Vitamin A and iron status are improved by vitamin A and iron supplementation in pregnant Indonesian women

Vitamin A deficiency among pregnant women in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Vitamin A deficiency (VAD) during pregnancy is a public health challenge in low-income countries. There are inconsistent findings that can affect policy in planning appropriate intervention. This systematic review and meta-analysis were conducted to summarize the evidence in order to identify existing gaps and propose strategies to reduce VAD during pregnancy in Ethiopia.

METHODS

This study included published and unpublished observational studies searched from different databases (PubMed, CINHAL [EBSCO], Embase, Google Scholar, Directory of Open Access Journals, Web of Sciences, MEDLINE, Cochrane Library, Scopus, Google Search and MedNar). Statistical analysis was conducted using Stata version 14 software. Heterogeneity and publication bias were assessed. Forest plots were used to present the pooled prevalence using the random effects model.

RESULTS

A total of 37 618 pregnant women from 15 studies were included. The overall pooled prevalence of VAD was 29% (95% confidence interval 21 to 36) with I2=99.67% and p<0.001. Socio-economic and sociodemographic factors were identified as affecting vitamin A deficiencies among pregnant women.

CONCLUSIONS

Nearly one-third of pregnant women in Ethiopia had VAD. Strengthening intervention modalities that aimed to increase the uptake of vitamin A-rich foods can avert VAD among pregnant women in Ethiopia.

Iron preparations for women of reproductive age with iron deficiency anaemia in pregnancy (FRIDA): a systematic review and network meta-analysis

BACKGROUND

Numerous iron preparations are available for the treatment of iron deficiency anaemia in pregnancy. We aimed to provide a summary of the effectiveness and safety of iron preparations used in this setting.

METHODS

We did a systematic review and network meta-analysis of randomised trials. We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, trial registers, and grey literature for trials published in any language from Jan 1, 2011, to Feb 28, 2021. We included trials including pregnant women with iron deficiency anaemia and evaluating iron preparations, irrespective of administration route, with at least 60 mg of elemental iron, in comparison with another iron or non-iron preparation. Three authors independently selected studies, extracted data, and did a risk of bias assessment using the Cochrane tool (version 1.0). The primary outcome was the effectiveness of iron preparations, evaluated by changes in haemoglobin concentration at 4 weeks from baseline. The secondary outcomes were change in serum ferritin concentration at 4 weeks from baseline and treatment-related severe and non-severe adverse events. We did random-effects pairwise and network meta-analyses. Side-effects were reported descriptively for each trial. This study is registered with PROSPERO, CRD42018100822.

FINDINGS

Among 3037 records screened, 128 full-text articles were further assessed for eligibility. Of the 53 eligible trials (reporting on 9145 women), 30 (15 interventions; 3243 women) contributed data to the network meta-analysis for haemoglobin and 15 (nine interventions; 1396 women) for serum ferritin. The risk of bias varied across the trials contributing to network meta-analysis, with 22 of 30 trials in the network meta-analysis for haemoglobin judged to have a high or medium global risk of bias. Compared with oral ferrous sulfate, intravenous iron sucrose improved both haemoglobin (mean difference 7·17 g/L, 95% CI 2·62-11·73; seven trials) and serum ferritin (mean difference 49·66 μg/L, 13·63-85·69; four trials), and intravenous ferric carboxymaltose improved haemoglobin (mean difference 8·52 g/L, 0·51-16·53; one trial). The evidence for other interventions compared with ferrous sulfate was insufficient. The most common side-effects with oral iron preparations were gastrointestinal effects (nausea, vomiting, and altered bowel movements). Side-effects were less common with parenteral iron preparations, although these included local pain, skin irratation, and, on rare occasions, allergic reactions.

INTERPRETATION

Iron preparations for treatment of iron deficiency anaemia in pregnancy vary in effectiveness, with good evidence of benefit for intravenous iron sucrose and some evidence for intravenous ferric carboxymaltose. Clinicians and policy makers should consider the effectiveness of individual preparations before administration, to ensure effective treatment.

FUNDING

None.

Effects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review

Background

Almost two billion people who are deficient in vitamins and minerals are women and children in low- and middle-income countries (LMIC). These deficiencies are worsened during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child. To reduce micronutrient deficiencies, several strategies have been implemented, including diet diversification, large-scale and targeted fortification, staple crop bio-fortification and micronutrient supplementation.

Objectives

To evaluate and summarize the available evidence on the effects of micronutrient supplementation during pregnancy in LMIC on maternal, fetal, child health and child development outcomes. This review will assess the impact of single micronutrient supplementation (calcium, vitamin A, iron, vitamin D, iodine, zinc, vitamin B12), iron-folic acid (IFA) supplementation, multiple micronutrient (MMN) supplementation, and lipid-based nutrient supplementation (LNS) during pregnancy.

Search Methods

We searched papers published from 1995 to 31 October 2019 (related programmes and good quality studies pre-1995 were limited) in CAB Abstracts, CINAHL, Cochrane Central Register of Controlled Trials, Embase, International Initiative for Impact Evaluations, LILACS, Medline, POPLINE, Web of Science, WHOLIS, ProQuest Dissertations & Theses Global, R4D, WHO International Clinical Trials Registry Platform. Non-indexed grey literature searches were conducted using Google, Google Scholar, and web pages of key international nutrition agencies.

Selection Criteria

We included randomized controlled trials (individual and cluster-randomized) and quasi-experimental studies that evaluated micronutrient supplementation in healthy, pregnant women of any age and parity living in a LMIC. LMIC were defined by the World Bank Group at the time of the search for this review. While the aim was to include healthy pregnant women, it is likely that these populations had one or more micronutrient deficiencies at baseline; women were not excluded on this basis.

Data Collection and Analysis

Two authors independently assessed studies for inclusion and risk of bias, and conducted data extraction. Data were matched to check for accuracy. Quality of evidence was assessed using the GRADE approach.

Main Results

A total of 314 papers across 72 studies (451,723 women) were eligible for inclusion, of which 64 studies (439,649 women) contributed to meta-analyses. Seven studies assessed iron-folic acid (IFA) supplementation versus folic acid; 34 studies assessed MMN vs. IFA; 4 studies assessed LNS vs. MMN; 13 evaluated iron; 13 assessed zinc; 9 evaluated vitamin A; 11 assessed vitamin D; and 6 assessed calcium. Several studies were eligible for inclusion in multiple types of supplementation. IFA compared to folic acid showed a large and significant (48%) reduction in the risk of maternal anaemia (average risk ratio (RR) 0.52, 95% CI 0.41 to 0.66; studies = 5; participants = 15,540; moderate-quality evidence). As well, IFA supplementation demonstrated a smaller but significant, 12% reduction in risk of low birthweight (LBW) babies (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). MMN supplementation was defined as any supplement that contained at least 3 micronutrients. Post-hoc analyses were conducted, where possible, comparing the differences in effect of MMN with 4+ components and MMN with 3 or 4 components. When compared to iron with or without FA, MMN supplementation reduced the risk of LBW by 15% (average RR 0.85, 95% CI 0.77 to 0.93; studies = 28; participants = 79,972); this effect was greater in MMN with >4 micronutrients (average RR 0.79, 95% CI 0.71 to 0.88; studies = 19; participants = 68,138 versus average RR 1.01, 95% CI 0.92 to 1.11; studies = 9; participants = 11,834). There was a small and significant reduction in the risk of stillbirths (average RR 0.91; 95% CI 0.86 to 0.98; studies = 22; participants = 96,772) and a small and significant effect on the risk of small-for-gestational age (SGA) (average RR 0.93; 95% CI 0.88 to 0.98; studies = 19; participants = 52,965). For stillbirths and SGA, the effects were greater among those provided MMN with 4+ micronutrients. Children whose mothers had been supplemented with MMN, compared to IFA, demonstrated a 16% reduced risk of diarrhea (average RR 0.84; 95% CI 0.76 to 0.92; studies = 4; participants = 3,142). LNS supplementation, compared to MMN, made no difference to any outcome; however, the evidence is limited. Iron supplementation, when compared to no iron or placebo, showed a large and significant effect on maternal anaemia, a reduction of 47% (average RR 0.53, 95% CI 0.43 to 0.65; studies = 6; participants = 15,737; moderate-quality evidence) and a small and significant effect on LBW (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). Zinc and vitamin A supplementation, each both compared to placebo, had no impact on any outcome examined with the exception of potentially improving serum/plasma zinc (mean difference (MD) 0.43 umol/L; 95% CI -0.04 to 0.89; studies = 5; participants = 1,202) and serum/plasma retinol (MD 0.13 umol/L; 95% CI -0.03 to 0.30; studies = 6; participants = 1,654), respectively. When compared to placebo, vitamin D supplementation may have reduced the risk of preterm births (average RR 0.64; 95% CI 0.40 to 1.04; studies = 7; participants = 1,262), though the upper CI just crosses the line of no effect. Similarly, calcium supplementation versus placebo may have improved rates of pre-eclampsia/eclampsia (average RR 0.45; 95% CI 0.19 to 1.06; studies = 4; participants = 9,616), though the upper CI just crosses 1.

Authors' Conclusions

The findings suggest that MMN and vitamin supplementation improve maternal and child health outcomes, including maternal anaemia, LBW, preterm birth, SGA, stillbirths, micronutrient deficiencies, and morbidities, including pre-eclampsia/eclampsia and diarrhea among children. MMN supplementation demonstrated a beneficial impact on the most number of outcomes. In addition, MMN with >4 micronutrients appeared to be more impactful than MMN with only 3 or 4 micronutrients included in the tablet. Very few studies conducted longitudinal analysis on longer-term health outcomes for the child, such as anthropometric measures and developmental outcomes; this may be an important area for future research. This review may provide some basis to guide continual discourse around replacing IFA supplementation with MMN along with the use of single micronutrient supplementation programs for specific outcomes.

Systematic Review and Meta-Analysis of the Relative Dose-Response Tests to Assess Vitamin A Status

Vitamin A (VA) is an essential nutrient often lacking in the diets of people in developing countries. Accurate biomarkers of VA status are vital to inform public health policy and monitor interventions. The relative dose-response (RDR) and modified-RDR (MRDR) tests are semi-quantitative screening tests for VA deficiency that have been used in Demographic and Health Surveys and VA intervention studies. A systematic review and meta-analysis of sensitivity and specificity were conducted to summarize the physiological evidence to support the RDR tests as methods to assess VA status and investigate the impact of different pathological and physiological states on the tests. A total of 190 studies were screened for inclusion, with 21 studies comparing the RDR tests with the gold-standard biomarker, liver VA concentration (68% and 80% sensitivity and 85% and 69% specificity for the RDR and MRDR, respectively). Nearly all studies with VA interventions in VA-deficient populations demonstrated a response of the tests to VA intake that would be expected to improve VA status. The impacts of chronic liver disease, protein malnutrition, age, pregnancy and lactation, infection and inflammation, and various other conditions were examined in 51 studies. The RDR and MRDR tests were reported to have been used in 39 observational studies, and the MRDR has been used in at least 6 national micronutrient surveys. The RDR and MRDR are sensitive tests for determining population VA status and assessing VA interventions. Although they are robust to most physiological and pathological states, caution may be warranted when using the tests in neonates, individuals with chronic liver disease, and those with protein or iron malnutrition. Research on further improvements to the tests to increase accessibility, such as sampling breast milk instead of blood or using intramuscular doses in subjects with malabsorption, will allow wider adoption. This review was registered with PROSPERO as CRD42019124180.

Differences in Micronutrient Intakes of Exclusive and Partially Breastfed Indonesian Infants from Resource-Poor Households are Not Accompanied by Differences in Micronutrient Status, Morbidity, or Growth

BACKGROUND

When maternal micronutrient intakes and statuses are compromised, reductions in micronutrient concentrations in neonatal stores and human milk may result in suboptimal micronutrient intakes, statuses, and functional outcomes of breastfed infants during the critical first 6-month period.

OBJECTIVES

We compared the adequacy of micronutrient intakes and statuses at 2 and/or 5 months and morbidity and growth faltering at 2, 5, and 12 months in a cohort of exclusively breastfed (EBF) and partially breastfed (PBF) infants from low-resource Indonesian households.

METHODS

At 2 and 5 months, the breastfeeding status and human milk intake of 212 infants were determined using the deuterium oxide dose-to-mother technique, and intakes were calculated from milk micronutrient concentrations and 3-d weighed food intakes. At 5 months, five infant micronutrient biomarkers, hemoglobin, C-reactive protein, and α-1-acid-glycoprotein were measured. Infant morbidity, weight, and length were measured at 2, 5, and 12 months. Means, medians, or proportions were reported for each group and differences between groups were statistically determined.

RESULTS

Median intakes of iron, thiamin, niacin, and vitamin B-12 were higher in PBF than EBF infants at 5 months (all P values < 0.05), but intakes in all infants were below adequate intakes. At 5 months, anemia was <20% in both groups, although fewer PBF versus EBF infants had vitamin B-12 deficiency (11.5% vs. 28.6%, respectively; P = 0.011). The mean ± SD length-for-age z-scores for EBF versus PBF infants at 2 months were 0.7 ± 0.9 versus -0.5 ± 1.1, respectively  (P = 0.158), declining to -1.4 ± 0.9 versus -1.1 ± 1.2, respectively, at 12 months (P = 0.059). Reported morbidity rates were generally low, with no evidence of a difference between infant groups (all P values > 0.126).

CONCLUSIONS

Irrespective of exclusive or partial breastfeeding status, micronutrient intakes of infants were low, statuses were compromised, and growth faltering during the critical 6 months period of early infancy was present. The findings highlight the importance of improving maternal nutritional statuses and evaluating their impacts on infant outcomes.

Vitamin A Requirements in Pregnancy and Lactation

Pregnancy and lactation are critical life stages with unique nutritional requirements, including for vitamin A (VA). Current DRIs for VA were published in 2001. The objective of this review was to identify and categorize evidence related to VA requirements in pregnancy and lactation since these DRIs were formulated. We searched MEDLINE and included articles according to an analytic framework of maternal VA exposure on status and health outcomes in the mother-child dyad. Intermediate and indirect evidence supports that maternal VA intakes can impact the mother's VA status, breastmilk, and health outcomes, as well as the child's VA status and select health outcomes. Food-based approaches can lead to more sustained, sufficient VA status in mothers and children. Research needs include further study linking maternal VA intakes on maternal and child VA status, and further associations with outcomes to determine intake requirements to optimize health.

Diagnosis of night blindness through standardized interview and electroretinography

Introduction

Objective: To compare the diagnosis of NB through the use of the standardized interview of the World Health Organization/Pan American Health Organization (WHO/PAHO) with electroretinography, and also to evaluate the association of these diagnoses with serum concentrations of retinol in class III obesity individuals. Methods: Adult patients of both genders, in the 20-60 age group, with BMI ≥ 40 kg/m² were studied. NB was diagnosed through electroretinography and the standardized interview validated by the WHO/PAHO. Serum level of retinol was quantified by the HPLC-UV method, and VAD was diagnosed when levels were <1.05 µmol /L, and severity was also evaluated. Statistical analysis was carried out through the Statistical Package for the Social Sciences, version 21.0 (p < 0.05). Results: Mean BMI was 44.9  11.8 kg/m², and a negative correlation was found in serum levels of retinol (p= 0.01). The prevalence of VAD, according to the serum concentrations of retinol, was 14%, and of this percentage 23.3% had NB according to the standardized interview, and 22.0% according to electroretinography. NB diagnosed by both methods showed an association with VAD according to the serum concentrations of retinol. Of these individuals with NB, according to the standardized interview, 6.9% showed severe VAD, 10.3% moderate VAD and 82.8% marginal VAD. Conclusion: The standardized interview for the diagnosis of NB can be a good strategy to evaluate the nutritional status of vitamin A, and it is a simple, non-invasive and low-cost method.

Vitamin and Mineral Supplementation During Pregnancy on Maternal, Birth, Child Health and Development Outcomes in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Almost two billion people are deficient in key vitamins and minerals, mostly women and children in low- and middle-income countries (LMICs). Deficiencies worsen during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child, but could be mitigated by interventions like micronutrient supplementation. To our knowledge, this is the first systematic review that aimed to compile evidence from both efficacy and effectiveness trials, evaluating different supplementation interventions on maternal, birth, child health, and developmental outcomes. We evaluated randomized controlled trials and quasi-experimental studies published since 1995 in peer-reviewed and grey literature that assessed the effects of calcium, vitamin A, iron, vitamin D, and zinc supplementation compared to placebo/no treatment; iron-folic (IFA) supplementation compared to folic acid only; multiple micronutrient (MMN) supplementation compared to IFA; and lipid-based nutrient supplementation (LNS) compared to MMN supplementation. Seventy-two studies, which collectively involved 314 papers (451,723 women), were included. Meta-analyses showed improvement in several key birth outcomes, such as preterm birth, small-for-gestational age (SGA) and low birthweight with MMN supplementation, compared to IFA. MMN also improved child outcomes, including diarrhea incidence and retinol concentration, which are findings not previously reported. Across all comparisons, micronutrient supplementation had little to no effect on mortality (maternal, neonatal, perinatal, and infant) outcomes, which is consistent with other systematic reviews. IFA supplementation showed notable improvement in maternal anemia and the reduction in low birthweight, whereas LNS supplementation had no apparent effect on outcomes; further research that compares LNS and MMN supplementation could help understand differences with these commodities. For single micronutrient supplementation, improvements were noted in only a few outcomes, mainly pre-eclampsia/eclampsia (calcium), maternal anemia (iron), preterm births (vitamin D), and maternal serum zinc concentration (zinc). These findings highlight that micronutrient-specific supplementation should be tailored to specific groups or needs for maximum benefit. In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.

Multiple-micronutrient supplementation for women during pregnancy

BACKGROUND

Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- and middle-income countries. They are exacerbated in pregnancy due to the increased demands of the developing fetus, leading to potentially adverse effects on the mother and baby. A consensus is yet to be reached regarding the replacement of iron and folic acid supplementation with MMNs. Since the last update of this Cochrane Review in 2017, evidence from several trials has become available. The findings of this review will be critical to inform policy on micronutrient supplementation in pregnancy.

OBJECTIVES

To evaluate the benefits of oral multiple-micronutrient supplementation during pregnancy on maternal, fetal and infant health outcomes.

SEARCH METHODS

For this 2018 update, on 23 February 2018 we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies. We also contacted experts in the field for additional and ongoing trials.

SELECTION CRITERIA

All prospective randomised controlled trials evaluating MMN supplementation with iron and folic acid during pregnancy and its effects on pregnancy outcomes were eligible, irrespective of language or the publication status of the trials. We included cluster-randomised trials, but excluded quasi-randomised trials. Trial reports that were published as abstracts were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We identified 21 trials (involving 142,496 women) as eligible for inclusion in this review, but only 20 trials (involving 141,849 women) contributed data. Of these 20 trials, 19 were conducted in low- and middle-income countries and compared MMN supplements with iron and folic acid to iron, with or without folic acid. One trial conducted in the UK compared MMN supplementation with placebo. In total, eight trials were cluster-randomised.MMN with iron and folic acid versus iron, with or without folic acid (19 trials)MMN supplementation probably led to a slight reduction in preterm births (average risk ratio (RR) 0.95, 95% confidence interval (CI) 0.90 to 1.01; 18 trials, 91,425 participants; moderate-quality evidence), and babies considered small-for-gestational age (SGA) (average RR 0.92, 95% CI 0.88 to 0.97; 17 trials; 57,348 participants; moderate-quality evidence), though the CI for the pooled effect for preterm births just crossed the line of no effect. MMN reduced the number of newborn infants identified as low birthweight (LBW) (average RR 0.88, 95% CI 0.85 to 0.91; 18 trials, 68,801 participants; high-quality evidence). We did not observe any differences between groups for perinatal mortality (average RR 1.00, 95% CI 0.90 to 1.11; 15 trials, 63,922 participants; high-quality evidence). MMN supplementation led to slightly fewer stillbirths (average RR 0.95, 95% CI 0.86 to 1.04; 17 trials, 97,927 participants; high-quality evidence) but, again, the CI for the pooled effect just crossed the line of no effect. MMN supplementation did not have an important effect on neonatal mortality (average RR 1.00, 95% CI 0.89 to 1.12; 14 trials, 80,964 participants; high-quality evidence). We observed little or no difference between groups for the other maternal and pregnancy outcomes: maternal anaemia in the third trimester (average RR 1.04, 95% CI 0.94 to 1.15; 9 trials, 5912 participants), maternal mortality (average RR 1.06, 95% CI 0.72 to 1.54; 6 trials, 106,275 participants), miscarriage (average RR 0.99, 95% CI 0.94 to 1.04; 12 trials, 100,565 participants), delivery via a caesarean section (average RR 1.13, 95% CI 0.99 to 1.29; 5 trials, 12,836 participants), and congenital anomalies (average RR 1.34, 95% CI 0.25 to 7.12; 2 trials, 1958 participants). However, MMN supplementation probably led to a reduction in very preterm births (average RR 0.81, 95% CI 0.71 to 0.93; 4 trials, 37,701 participants). We were unable to assess a number of prespecified, clinically important outcomes due to insufficient or non-available data.When we assessed primary outcomes according to GRADE criteria, the quality of evidence for the review overall was moderate to high. We graded the following outcomes as high quality: LBW, perinatal mortality, stillbirth, and neonatal mortality. The outcomes of preterm birth and SGA we graded as moderate quality; both were downgraded for funnel plot asymmetry, indicating possible publication bias.We carried out sensitivity analyses excluding trials with high levels of sample attrition (> 20%). We found that results were consistent with the main analyses for all outcomes. We explored heterogeneity through subgroup analyses by maternal height, maternal body mass index (BMI), timing of supplementation, dose of iron, and MMN supplement formulation (UNIMMAP versus non-UNIMMAP). There was a greater reduction in preterm births for women with low BMI and among those who took non-UNIMMAP supplements. We also observed subgroup differences for maternal BMI and maternal height for SGA, indicating greater impact among women with greater BMI and height. Though we found that MMN supplementation made little or no difference to perinatal mortality, the analysis demonstrated substantial statistical heterogeneity. We explored this heterogeneity using subgroup analysis and found differences for timing of supplementation, whereby higher impact was observed with later initiation of supplementation. For all other subgroup analyses, the findings were inconclusive.MMN versus placebo (1 trial)A single trial in the UK found little or no important effect of MMN supplementation on preterm births, SGA, or LBW but did find a reduction in maternal anaemia in the third trimester (RR 0.66, 95% CI 0.51 to 0.85), when compared to placebo. This trial did not measure our other outcomes.

AUTHORS' CONCLUSIONS

Our findings suggest a positive impact of MMN supplementation with iron and folic acid on several birth outcomes. MMN supplementation in pregnancy led to a reduction in babies considered LBW, and probably led to a reduction in babies considered SGA. In addition, MMN probably reduced preterm births. No important benefits or harms of MMN supplementation were found for mortality outcomes (stillbirths, perinatal and neonatal mortality). These findings may provide some basis to guide the replacement of iron and folic acid supplements with MMN supplements for pregnant women residing in low- and middle-income countries.

Effect of green leafy vegetables powder on anaemia and vitamin-A status of Ghanaian school children

BACKGROUND

Nutritional anaemia and vitamin-A deficiency are public health issues confronting Ghanaian children. Their adverse effects are likely pronounced during the dry season when green leafy vegetables, rich-sources of iron and provitamin-A are scarce. This study assessed the effect of dried green leafy vegetables on anaemia and vitamin-A status of Ghanaian school children.

METHOD

This was 3 months pretest, posttest nutrition intervention study. Children 4-9 years were randomized to receive or not receive supplement. High Performance Liquid Chromatography and Haemocue hemoglobinometer were used to determine vitamin-A and haemoglobin concentrations respectively. Malaria-parasitaemia and helminthes were examined by Giemsa-staining and Kato-Katz respectively. Nutritional status was assessed by anthropometry. Student's t-test was used to establish significant differences between groups.

RESULTS

At baseline, the mean haemoglobin concentrations of control and supplemental were 116.9 ± 9.9 g/l and 117.6 ± 12.7 g/l respectively. At end-line, it was 121.9 ± 13.5 g/l for supplemental and 113.4 ± 8.5 g/l for control, significant at p = 0.001. At baseline prevalence of anaemia was 37.3 and 41.5% in control and supplemental respectively. At end-line it was 33.3% in supplemental against 57.5% in control, significant at p = 0.024. At baseline mean retinol concentrations were 16.79 ± 8.74 μg/dl and 16.97 ± 7.74 μg/dl for control and supplemental respectively. Mean retinol concentrations for control and supplemental were 24.35 ± 5.50 μg/dl and 26.96 ± 6.86 μg/dl respectively at end-line. At end-line 60% of control against 64.0% of supplemental had low vitamin-A status. At end-line, anaemic-control had mean retinol concentration of 23.78 ± 5.23 μg/dl and anaemic-supplemental had 27.46 ± 7.28 μg/dl. Prevalence of low vitamin-A status was 64.3 and 84.2% in anaemic-control and anaemic-supplemental respectively at baseline but it became 23.1 and 21.1% respectively, at end-line. The mean haemoglobin concentrations of anaemic-control and supplemental were 105.7 ± 7.5 g/l and 113.6 ± 13.6 g/l respectively at end-line. The change in prevalence of anaemia between the anaemic groups was 12.2%, significant at p = 0.042.

CONCLUSION

Consumption of green leafy vegetables powder increased mean haemoglobin and retinol concentrations of the study participants. It had the potential to minimize prevalence of anaemia and low vitamin-A status of study participants.

Effect of vitamin A supplementation on iron status in humans: A systematic review and meta-analysis

Anemia is a worldwide public health problem that can be related to many causes, including vitamin A deficiency. The aim of this study was to assess and estimate the effect of vitamin A supplementation (VAS) on iron status biomarkers and anemia in humans. Six databases, including Cochrane, EMBASE, LILACS, Pubmed, Scopus and Web of Science, were searched for clinical trials and cohort studies that investigated the effect of vitamin A supplementation alone on iron status and anemia, without time-restriction. The search yielded 23 eligible studies, 21 clinical trials and 2 cohort studies, with children, teenagers, pregnant or lactating women. The meta-analysis of the clinical trials showed that VAS reduces the risk of anemia by 26% and raises hemoglobin levels, compared to non-treated group, independent of the life stage. VAS did not alter the prevalence of iron deficiency among the clinical trials conducted with children and teenagers (RR 0.82, 95% CI 0.60 to 1.12, p = 0.204), whereas a significant increase in serum ferritin levels was observed in trials conducted with pregnant and lactating women (WMD 6.61 μg/L; 95% CI 6.00 to 7.21 μg/L; p < 0.001). Therefore, vitamin A supplementation alone may reduce the risk of anemia, by improving hemoglobin and ferritin levels in individuals with low serum retinol levels.

Impact of Vitamin A Supplementation on Pregnant Women and on Women Who Have Just Given Birth: A Systematic Review

BACKGROUND

The aim of this review was to evaluate the impact of vitamin A supplementation on adult pregnant women and women who have just given birth in studies examining serum concentrations of vitamin A in breast milk and in maternal/child morbidity and mortality.

METHODS

This review followed the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). In November 2014, an electronic search was independently performed by two authors on the Medline, Scopus, Web of Science, and LILACS databases on studies published from January 2004 to November 2014. The methodological quality of the studies was assessed in accordance with the Jadad scale, which determines the exclusion of studies with scores lower than 3.

RESULTS

It was observed that when supplementation was provided only in the immediate postpartum period, it increased the liver stores of vitamin A. On the other hand, when supplementation was provided during pregnancy and puerperium5, the propensity for depleting the stores of vitamin A at the end of pregnancy decreased, the immune system improved, and cases of gestational night blindness decreased, but there were no changes in the outcomes at childbirth or in maternal, fetal, and child mortality. When supplementation was provided before and during pregnancy and in the immediate postpartum period, an additional improvement of lung function evaluated in preschool-aged children was found, but no significant changes in cognitive and motor development were noted.

CONCLUSIONS

Studies show the benefits of vitamin A supplementation, not just in the immediate postpartum period but, above all, when it is provided before and/or during pregnancy. Considering the positive repercussions observed, we suggest supplementation both in the gestational period and in the immediate postpartum period as a way to enhance the safety of mother-child care.

Multiple-micronutrient supplementation for women during pregnancy

BACKGROUND

Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- to middle-income countries. They are exacerbated in pregnancy due to the increased demands, leading to potentially adverse effects on the mother and developing fetus. Though supplementation with MMNs has been recommended earlier because of the evidence of impact on pregnancy outcomes, a consensus is yet to be reached regarding the replacement of iron and folic acid supplementation with MMNs. Since the last update of this Cochrane review, evidence from a few large trials has recently been made available, the inclusion of which is critical to inform policy.

OBJECTIVES

To evaluate the benefits of oral multiple-micronutrient supplementation during pregnancy on maternal, fetal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 March 2015) and reference lists of retrieved articles and key reviews. We also contacted experts in the field for additional and ongoing trials.

SELECTION CRITERIA

All prospective randomised controlled trials evaluating MMN supplementation with iron and folic acid during pregnancy and its effects on the pregnancy outcome were eligible, irrespective of language or the publication status of the trials. We included cluster-randomised trials, but quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Nineteen trials (involving 138,538 women) were identified as eligible for inclusion in this review but only 17 trials (involving 137,791 women) contributed data to the review. Fifteen of these 17 trials were carried out in low and middle-income countries and compared MMN supplements with iron and folic acid versus iron with or without folic acid. Two trials carried out in the UK compared MMN with a placebo. MMN with iron and folic acid versus iron, with or without folic acid (15 trials): MMN resulted in a significant decrease in the number of newborn infants identified as low birthweight (LBW) (average risk ratio (RR) 0.88, 95% confidence interval (CI) 0.85 to 0.91; high-quality evidence) or small-for-gestational age (SGA) (average RR 0.92, 95% CI 0.86 to 0.98; moderate-quality evidence). No significant differences were shown for other maternal and pregnancy outcomes: preterm births (average RR 0.96, 95% CI 0.90 to 1.03; high-quality evidence), stillbirth (average RR 0.97, 95% CI 0.87, 1.09; high-quality evidence), maternal anaemia in the third trimester (average RR 1.03, 95% CI 0.85 to 1.24), miscarriage (average RR 0.91, 95% CI 0.80 to 1.03), maternal mortality (average RR 0.97, 95% CI 0.63 to 1.48), perinatal mortality (average RR 1.01, 95% CI 0.91 to 1.13; high-quality evidence), neonatal mortality (average RR 1.06, 95% CI 0.92 to 1.22; high-quality evidence), or risk of delivery via a caesarean section (average RR 1.04; 95% CI 0.74 to 1.46).A number of prespecified, clinically important outcomes could not be assessed due to insufficient or non-available data. Single trials reported results for: very preterm birth < 34 weeks, macrosomia, side-effects of supplements, nutritional status of children, and congenital anomalies including neural tube defects and neurodevelopmental outcome: Bayley Scales of Infant Development (BSID) scores. None of these trials reported pre-eclampsia, placental abruption, premature rupture of membranes, cost of supplementation, and maternal well-being or satisfaction.When assessed according to GRADE criteria, the quality of evidence for the review's primary outcomes overall was good. Pooled results for primary outcomes were based on multiple trials with large sample sizes and precise estimates. The following outcomes were graded to be as of high quality: preterm birth, LBW, perinatal mortality, stillbirth and neonatal mortality. The outcome of SGA was graded to be of moderate quality, with evidence downgraded by one for funnel plot asymmetry and potential publication bias.We carried out sensitivity analysis excluding trials with high levels of sample attrition (> 20%); results were consistent with the main analysis except for the findings for SGA (average RR 0.91, 95% CI 0.84 to 1.00). We explored heterogeneity through subgroup analyses by maternal height and body mass index (BMI), timing of supplementation and dose of iron. Subgroup differences were observed for maternal BMI for the outcome preterm birth, with significant findings among women with low BMI. Subgroup differences were also observed for maternal BMI and maternal height for the outcome SGA, indicating a significant impact among women with higher maternal BMI and height. The overall analysis of perinatal mortality, although showed a non-significant effect of MMN supplements versus iron with or without folic acid, was found to have substantial statistical heterogeneity. Subgroup differences were observed for timing of supplementation for this outcome, indicating a significantly higher impact with late initiation of supplementation. The findings between subgroups for other primary outcomes were inconclusive. MMN versus placebo (two trials): A single trial in the UK found no clear differences between groups for preterm birth, SGA, LBW or maternal anaemia in the third trimester. A second trial reported the number of women with pre-eclampsia; there was no evidence of a difference between groups. Other outcomes were not reported.

AUTHORS' CONCLUSIONS

Our findings support the effect of MMN supplements with iron and folic acid in improving some birth outcomes. Overall, pregnant women who received MMN supplementation had fewer low birthweight babies and small-for-gestational-age babies. The findings, consistently observed in several systematic evaluations of evidence, provide a basis to guide the replacement of iron and folic acid with MMN supplements containing iron and folic acid for pregnant women in low and middle-income countries where MMN deficiencies are common among women of reproductive age. Efforts could focus on the integration of this intervention in maternal nutrition and antenatal care programs in low and middle-income countries.

Biomarkers of Nutrition for Development (BOND)-Vitamin A Review

The Biomarkers of Nutrition for Development (BOND) project is designed to provide evidence-informed advice to anyone with an interest in the role of nutrition in health. The BOND program provides information with regard to selection, use, and interpretation of biomarkers of nutrient exposure, status, function, and effect, which will be especially useful for readers who want to assess nutrient status. To accomplish this objective, expert panels are recruited to evaluate the literature and to draft comprehensive reports on the current state of the art with regard to specific nutrient biology and available biomarkers for assessing nutritional status at the individual and population levels. Phase I of the BOND project includes the evaluation of biomarkers for 6 nutrients: iodine, folate, zinc, iron, vitamin A, and vitamin B-12. This review of vitamin A is the current article in this series. Although the vitamin was discovered >100 y ago, vitamin A status assessment is not trivial. Serum retinol concentrations are under homeostatic control due in part to vitamin A's use in the body for growth and cellular differentiation and because of its toxic properties at high concentrations. Furthermore, serum retinol concentrations are depressed during infection and inflammation because retinol-binding protein (RBP) is a negative acute-phase reactant, which makes status assessment challenging. Thus, this review describes the clinical and functional indicators related to eye health and biochemical biomarkers of vitamin A status (i.e., serum retinol, RBP, breast-milk retinol, dose-response tests, isotope dilution methodology, and serum retinyl esters). These biomarkers are then related to liver vitamin A concentrations, which are usually considered the gold standard for vitamin A status. With regard to biomarkers, future research questions and gaps in our current understanding as well as limitations of the methods are described.

Vitamin supplementation for preventing miscarriage

BACKGROUND

Miscarriage is a common complication of pregnancy that can be caused by a wide range of factors. Poor dietary intake of vitamins has been associated with an increased risk of miscarriage, therefore supplementing women with vitamins either prior to or in early pregnancy may help prevent miscarriage.

OBJECTIVES

The objectives of this review were to determine the effectiveness and safety of any vitamin supplementation, on the risk of spontaneous miscarriage.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (6 November 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing supplementation during pregnancy with one or more vitamins with either placebo, other vitamins, no vitamins or other interventions. We have included supplementation that started prior to conception, periconceptionally or in early pregnancy (less than 20 weeks' gestation).

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion, extracted data and assessed trial quality. We assessed the quality of the evidence using the GRADE approach. The quality of evidence is included for numerical results of outcomes included in the 'Summary of findings' tables.

MAIN RESULTS

We included a total of 40 trials (involving 276,820 women and 278,413 pregnancies) assessing supplementation with any vitamin(s) starting prior to 20 weeks' gestation and reporting at least one primary outcome that was eligible for the review. Eight trials were cluster-randomised and contributed data for 217,726 women and 219,267 pregnancies in total.Approximately half of the included trials were assessed to have a low risk of bias for both random sequence generation and adequate concealment of participants to treatment and control groups. Vitamin C supplementation There was no difference in the risk of total fetal loss (risk ratio (RR) 1.14, 95% confidence interval (CI) 0.92 to 1.40, seven trials, 18,949 women; high-quality evidence); early or late miscarriage (RR 0.90, 95% CI 0.65 to 1.26, four trials, 13,346 women; moderate-quality evidence); stillbirth (RR 1.31, 95% CI 0.97 to 1.76, seven trials, 21,442 women; moderate-quality evidence) or adverse effects of vitamin supplementation (RR 1.16, 95% CI 0.39 to 3.41, one trial, 739 women; moderate-quality evidence) between women receiving vitamin C with vitamin E compared with placebo or no vitamin C groups. No clear differences were seen in the risk of total fetal loss or miscarriage between women receiving any other combination of vitamin C compared with placebo or no vitamin C groups. Vitamin A supplementation No difference was found in the risk of total fetal loss (RR 1.01, 95% CI 0.61 to 1.66, three trials, 1640 women; low-quality evidence); early or late miscarriage (RR 0.86, 95% CI 0.46 to 1.62, two trials, 1397 women; low-quality evidence) or stillbirth (RR 1.29, 95% CI 0.57 to 2.91, three trials, 1640 women; low-quality evidence) between women receiving vitamin A plus iron and folate compared with placebo or no vitamin A groups. There was no evidence of differences in the risk of total fetal loss or miscarriage between women receiving any other combination of vitamin A compared with placebo or no vitamin A groups. Multivitamin supplementation There was evidence of a decrease in the risk for stillbirth among women receiving multivitamins plus iron and folic acid compared iron and folate only groups (RR 0.92, 95% CI 0.85 to 0.99, 10 trials, 79,851 women; high-quality evidence). Although total fetal loss was lower in women who were given multivitamins without folic acid (RR 0.49, 95% CI 0.34 to 0.70, one trial, 907 women); and multivitamins with or without vitamin A (RR 0.60, 95% CI 0.39 to 0.92, one trial, 1074 women), these findings included one trial each with small numbers of women involved. Also, they include studies where the comparison groups included women receiving either vitamin A or placebo, and thus require caution in interpretation.We found no difference in the risk of total fetal loss (RR 0.96, 95% CI 0.93 to 1.00, 10 trials, 94,948 women; high-quality evidence) or early or late miscarriage (RR 0.98, 95% CI 0.94 to 1.03, 10 trials, 94,948 women; moderate-quality evidence) between women receiving multivitamins plus iron and folic acid compared with iron and folate only groups.There was no evidence of differences in the risk of total fetal loss or miscarriage between women receiving any other combination of multivitamins compared with placebo, folic acid or vitamin A groups. Folic acid supplementation There was no evidence of any difference in the risk of total fetal loss, early or late miscarriage, stillbirth or congenital malformations between women supplemented with folic acid with or without multivitamins and/or iron compared with no folic acid groups. Antioxidant vitamins supplementation There was no evidence of differences in early or late miscarriage between women given antioxidant compared with the low antioxidant group (RR 1.12, 95% CI 0.24 to 5.29, one trial, 110 women).

AUTHORS' CONCLUSIONS

Taking any vitamin supplements prior to pregnancy or in early pregnancy does not prevent women experiencing miscarriage. However, evidence showed that women receiving multivitamins plus iron and folic acid had reduced risk for stillbirth. There is insufficient evidence to examine the effects of different combinations of vitamins on miscarriage and miscarriage-related outcomes.

Current Capabilities and Limitations of Stable Isotope Techniques and Applied Mathematical Equations in Determining Whole-Body Vitamin A Status

BACKGROUND

Retinol isotope dilution (RID) methodology provides a quantitative estimate of total body vitamin A (VA) stores and is the best method currently available for assessing VA status in adults and children. The methodology has also been used to test the efficacy of VA interventions in a number of low-income countries. Infections, micronutrient deficiencies (eg, iron and zinc), liver disease, physiological age, pregnancy, and lactation are known or hypothesized to influence the accuracy of estimating total body VA stores using the isotope dilution technique.

OBJECTIVE

Our objectives were to review the strengths and limitations of RID methods, to discuss what is known about the impact of various factors on results, and to summarize contributions of model-based compartmental analysis to assessing VA status.

METHODS

Relevant published literature is reviewed and discussed.

RESULTS

Various equations and compartmental modeling have been used to estimate the total body VA stores using stable isotopes, including a newer 3-day equation that provides an estimate of total body VA stores in healthy adults. At present, there is insufficient information on absorption of the isotope tracer, and there is a need to further investigate how various factors impact the application of RID techniques in field studies.

CONCLUSIONS

Isotope dilution methodology can provide useful estimates of total body VA stores in apparently healthy populations under controlled study conditions. However, more research is needed to determine whether the method is suitable for use in settings where there is a high prevalence of infection, iron deficiency, and/or liver disease.

Multiple-micronutrient supplementation for women during pregnancy

BACKGROUND

Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- to middle-income countries. They are exacerbated in pregnancy due to the increased demands, leading to potentially adverse effects on the mother and developing fetus. Though supplementation with MMNs has been recommended earlier because of the evidence of impact on pregnancy outcomes, a consensus is yet to be reached regarding the replacement of iron and folic acid supplementation with MMNs. Since the last update of this Cochrane review, evidence from a few large trials has recently been made available, the inclusion of which is critical to inform policy.

OBJECTIVES

To evaluate the benefits of oral multiple-micronutrient supplementation during pregnancy on maternal, fetal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 March 2015) and reference lists of retrieved articles and key reviews. We also contacted experts in the field for additional and ongoing trials.

SELECTION CRITERIA

All prospective randomised controlled trials evaluating MMN supplementation during pregnancy and its effects on the pregnancy outcome were eligible, irrespective of language or the publication status of the trials. We included cluster-randomised trials, but quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Nineteen trials (involving 138,538 women) were identified as eligible for inclusion in this review but only 17 trials (involving 137,791 women) contributed data to the review. Fifteen of these 17 trials were carried out in low and middle-income countries and compared MMN supplements with iron and folic acid versus iron with or without folic acid. Two trials carried out in the UK compared MMN with a placebo. MMN with iron and folic acid versus iron, with or without folic acid (15 trials): MMN resulted in a significant decrease in the number of newborn infants identified as low birthweight (LBW) (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.85 to 0.91; high-quality evidence) or small-for-gestational age (SGA) (average RR 0.90, 95% CI 0.83 to 0.97; moderate-quality evidence), and a reduced rate of stillbirth (RR 0.91, 95% CI 0.85 to 0.98; high-quality evidence). No significant differences were shown for other maternal and pregnancy outcomes: preterm births (RR 0.96, 95% CI 0.89 to 1.03; high-quality evidence), maternal anaemia in the third trimester (RR 0.97, 95% CI 0.86 to 1.10), miscarriage (RR 0.89, 95% CI 0.78 to 1.01), maternal mortality (RR 0.97, 95% CI 0.63 to 1.48), perinatal mortality (RR 0.97, 95% CI 0.84 to 1.12; high-quality evidence), neonatal mortality (RR 0.98, 95% CI 0.90 to 1.07; high -quality evidence), or risk of delivery via a caesarean section (RR 1.03; 95% CI 0.75 to 1.43).A number of prespecified, clinically important outcomes could not be assessed due to insufficient or non-available data. Single trials reported results for: very preterm birth < 34 weeks, macrosomia, side-effects of supplements, nutritional status of children, and congenital anomalies including neural tube defects and neurodevelopmental outcome: Bayley Scales of Infant Development (BSID) scores. None of these trials reported pre-eclampsia, placental abruption, premature rupture of membranes, cost of supplementation, and maternal well-being or satisfaction.When assessed according to GRADE criteria, the quality of evidence for the review's primary outcomes overall was good. Pooled results for primary outcomes were based on multiple trials with large sample sizes and precise estimates. The following outcomes were graded to be as of high quality: preterm birth, LBW, perinatal mortality, stillbirth and neonatal mortality. The outcome of SGA was graded to be of moderate quality, with evidence downgraded by one for funnel plot asymmetry and potential publication bias.We carried out sensitivity analysis excluding trials with high levels of sample attrition (> 20%); results were consistent with the main analysis. We explored heterogeneity through subgroup analysis by maternal height and body mass index (BMI), timing of supplementation and dose of iron. Subgroup differences were observed for maternal BMI and timing of supplementation for the outcome preterm birth, with significant findings among women with low BMI and with earlier initiation of supplementation in the prenatal period. Subgroup differences were also observed for maternal BMI, maternal height and dose of iron for the outcome SGA, indicating a significant impact among women with higher maternal BMI and height, and with MMN supplement containing 30 mg of iron versus control receiving 60 mg of iron. The findings between subgroups for other primary outcomes were inconclusive. MMN versus placebo (two trials): A single trial in the UK found no clear differences between groups for preterm birth, SGA, LBW or maternal anaemia in the third trimester. A second trial reported the number of women with pre-eclampsia; there was no evidence of a difference between groups. Other outcomes were not reported.

AUTHORS' CONCLUSIONS

Our findings support the effect of MMN supplements with iron and folic acid in improving birth outcomes. The findings, consistently observed in several systematic evaluations of evidence, provide a strong basis to guide the replacement of iron and folic acid with MMN supplements containing iron and folic acid for pregnant women in developing countries where MMN deficiencies are common among women of reproductive age. Efforts should be focused on the integration of this intervention in maternal nutrition and antenatal care programs in developing countries.

Vitamin A supplementation during pregnancy for maternal and newborn outcomes

BACKGROUND

The World Health Organization recommends routine vitamin A supplementation during pregnancy or lactation in areas with endemic vitamin A deficiency (where night blindness occurs), based on the expectation that supplementation will improve maternal and newborn outcomes including mortality, morbidity and prevention of anaemia or infection.  

OBJECTIVES

To review the effects of supplementation of vitamin A, or one of its derivatives, during pregnancy, alone or in combination with other vitamins and micronutrients, on maternal and newborn clinical outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 March 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised or quasi-randomised trials, including cluster-randomised trials, evaluating the effect of vitamin A supplementation in pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

We reviewed 106 reports of 35 trials, published between 1931 and 2015. We included 19 trials including over 310,000 women, excluded 15 trials and one is ongoing. Overall, seven trials were judged to be of low risk of bias, three were high risk of bias and for nine it was unclear. 1) Vitamin A alone versus placebo or no treatmentOverall, when trial results are pooled, vitamin A supplementation does not affect the risk of maternal mortality (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.65 to 1.20; four trials Ghana, Nepal, Bangladesh, UK, high quality evidence), perinatal mortality (RR 1.01, 95% CI 0.95 to 1.07; one study, high quality evidence), neonatal mortality, stillbirth, neonatal anaemia, preterm birth (RR 0.98, 95% CI 0.94 to 1.01, five studies, high quality evidence), or the risk of having a low birthweight baby.Vitamin A supplementation reduces the risk of maternal night blindness (RR 0.79, 95% CI 0.64 to 0.98; two trials). There is evidence that vitamin A supplements may reduce maternal clinical infection (RR 0.45, 95% CI 0.20 to 0.99, five trials; South Africa, Nepal, Indonesia, Tanzania, UK, low quality evidence) and maternal anaemia (RR 0.64, 95% CI 0.43 to 0.94; three studies, moderate quality evidence). 2) Vitamin A alone versus micronutrient supplements without vitamin AVitamin A alone compared to micronutrient supplements without vitamin A does not decrease maternal clinical infection (RR 0.99, 95% CI 0.83 to 1.18, two trials, 591 women). No other primary or secondary outcomes were reported 3) Vitamin A with other micronutrients versus micronutrient supplements without vitamin AVitamin A supplementation (with other micronutrients) does not decrease perinatal mortality (RR 0.51, 95% CI 0.10 to 2.69; one study, low quality evidence), maternal anaemia (RR 0.86, 95% CI 0.68 to 1.09; three studies, low quality evidence), maternal clinical infection (RR 0.95, 95% CI 0.80 to 1.13; I² = 45%, two studies, low quality evidence) or preterm birth (RR 0.39, 95% CI 0.08 to 1.93; one study, low quality evidence).In HIV-positive women vitamin A supplementation given with other micronutrients was associated with fewer low birthweight babies (< 2.5 kg) in the supplemented group in one study (RR 0.67, 95% CI 0.47 to 0.96; one study, 594 women).

AUTHORS' CONCLUSIONS

The pooled results of three large trials in Nepal, Ghana and Bangladesh (with over 153,500 women) do not currently suggest a role for antenatal vitamin A supplementation to reduce maternal or perinatal mortality. However, the populations studied were probably different with regard to baseline vitamin A status and there were problems with follow-up of women. There is good evidence that antenatal vitamin A supplementation reduces maternal night blindness, maternal anaemia for women who live in areas where vitamin A deficiency is common or who are HIV-positive. In addition the available evidence suggests a reduction in maternal infection, but these data are not of a high quality.

Effects of vitamin A supplementation on iron status indices and iron deficiency anaemia: a randomized controlled trial

Iron deficiency anaemia (IDA) is the most common nutritional deficiency in the world including developed and developing countries. Despite intensive efforts to improve the quality of life of rural and aboriginal communities in Malaysia, anaemia and IDA are still major public health problems in these communities particularly among children. A randomized, double-blind, placebo-controlled trial was conducted on 250 Orang Asli (aboriginal) schoolchildren in Malaysia to investigate the effects of a single high-dose of vitamin A supplementation (200,000 IU) on iron status indices, anaemia and IDA status. The effect of the supplement was assessed after 3 months of receiving the supplements; after a complete 3-day deworming course of 400 mg/day of albendazole tablets. The prevalence of anaemia was found to be high: 48.5% (95% CI=42.3, 54.8). Moreover, 34% (95% CI=28.3, 40.2) of the children had IDA, which accounted for 70.1% of the anaemic cases. The findings showed that the reduction in serum ferritin level and the increments in haemoglobin, serum iron and transferrin saturation were found to be significant among children allocated to the vitamin A group compared to those allocated to the placebo group (p<0.01). Moreover, a significant reduction in the prevalence of IDA by almost 22% than prevalence at baseline was reported among children in the vitamin A group compared with only 2.3% reduction among children in the placebo group. In conclusion, vitamin A supplementation showed a significant impact on iron status indices and IDA among Orang Asli children. Hence, providing vitamin A supplementation and imparting the knowledge related to nutritious food should be considered in the efforts to improve the nutritional and health status of these children as a part of efforts to improve the quality of life in rural and aboriginal communities.

The influence of vitamin A supplementation on iron status

Vitamin A (VA) and iron deficiencies are important nutritional problems, affecting particularly preschool children, as well as pregnant and lactating women. A PubMed (National Library of Medicine, National Institutes of Health, Bethesda, MD, USA) literature review was carried out to search for clinical trials published from 1992 to 2013 that assessed the influence of vitamin A supplementation on iron status. Simultaneous use of iron and vitamin A supplements seemed to be more effective to prevent iron deficiency anemia than the use of these micronutrients alone. Some studies did not include a placebo group and only a few of them assessed vitamin A status of the individuals at baseline. Moreover, the studies did not consider any inflammatory marker and a reasonable number of iron parameters. Another important limitation was the lack of assessment of hemoglobin variants, especially in regions with a high prevalence of anemia. Assessment of hemoglobin variants, inflammatory markers and anemia of chronic inflammation would be important to the studies investigated. Studies involving different populations are necessary to elucidate the interaction between the two micronutrients, especially regarding iron absorption and modulation of erythropoiesis.

Anaemia, prenatal iron use, and risk of adverse pregnancy outcomes: systematic review and meta-analysis

OBJECTIVES

To summarise evidence on the associations of maternal anaemia and prenatal iron use with maternal haematological and adverse pregnancy outcomes; and to evaluate potential exposure-response relations of dose of iron, duration of use, and haemoglobin concentration in prenatal period with pregnancy outcomes.

DESIGN

Systematic review and meta-analysis

DATA SOURCES

Searches of PubMed and Embase for studies published up to May 2012 and references of review articles.

STUDY SELECTION CRITERIA

Randomised trials of prenatal iron use and prospective cohort studies of prenatal anaemia; cross sectional and case-control studies were excluded.

RESULTS

48 randomised trials (17 793 women) and 44 cohort studies (1 851 682 women) were included. Iron use increased maternal mean haemoglobin concentration by 4.59 (95% confidence interval 3.72 to 5.46) g/L compared with controls and significantly reduced the risk of anaemia (relative risk 0.50, 0.42 to 0.59), iron deficiency (0.59, 0.46 to 0.79), iron deficiency anaemia (0.40, 0.26 to 0.60), and low birth weight (0.81, 0.71 to 0.93). The effect of iron on preterm birth was not significant (relative risk 0.84, 0.68 to 1.03). Analysis of cohort studies showed a significantly higher risk of low birth weight (adjusted odds ratio 1.29, 1.09 to 1.53) and preterm birth (1.21, 1.13 to 1.30) with anaemia in the first or second trimester. Exposure-response analysis indicated that for every 10 mg increase in iron dose/day, up to 66 mg/day, the relative risk of maternal anaemia was 0.88 (0.84 to 0.92) (P for linear trend<0.001). Birth weight increased by 15.1 (6.0 to 24.2) g (P for linear trend=0.005) and risk of low birth weight decreased by 3% (relative risk 0.97, 0.95 to 0.98) for every 10 mg increase in dose/day (P for linear trend<0.001). Duration of use was not significantly associated with the outcomes after adjustment for dose. Furthermore, for each 1 g/L increase in mean haemoglobin, birth weight increased by 14.0 (6.8 to 21.8) g (P for linear trend=0.002); however, mean haemoglobin was not associated with the risk of low birth weight and preterm birth. No evidence of a significant effect on duration of gestation, small for gestational age births, and birth length was noted.

CONCLUSIONS

Daily prenatal use of iron substantially improved birth weight in a linear dose-response fashion, probably leading to a reduction in risk of low birth weight. An improvement in prenatal mean haemoglobin concentration linearly increased birth weight.

An evidence-based systematic review of vitamin A by the natural standard research collaboration

An evidence-based systematic review of vitamin A by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated and reproducible grading rationale. This paper includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Multiple-micronutrient supplementation for women during pregnancy

BACKGROUND

Multiple-micronutrient deficiencies often coexist in low- to middle-income countries. They are exacerbated in pregnancy due to the increased demands, leading to potentially adverse effects on the mother. Substantive evidence regarding the effectiveness of multiple-micronutrient supplements (MMS) during pregnancy is not available.

OBJECTIVES

To evaluate the benefits to both mother and infant of multiple-micronutrient supplements in pregnancy and to assess the risk of adverse events as a result of supplementation.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (17 February 2012) and reference lists of retrieved articles and key reviews. We also contacted experts in the field for additional and ongoing trials.

SELECTION CRITERIA

All prospective randomised controlled trials evaluating multiple-micronutrient supplementation during pregnancy and its effects on the pregnancy outcome, irrespective of language or publication status of the trials. We included cluster-randomised trials but quasi-randomised trials were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and trial quality. Two review authors independently extracted the data. Data were checked for accuracy.

MAIN RESULTS

Twenty-three trials (involving 76,532 women) were identified as eligible for inclusion in this review but only 21 trials (involving 75,785 women) contributed data to the review.When compared with iron and folate supplementation, MMS resulted in a statistically significant decrease in the number of low birthweight babies (risk ratio (RR) 0.89; 95% confidence interval (CI) 0.83 to 0.94) and small-for-gestational age (SGA) babies (RR 0.87; 95% CI 0.81 to 0.95). No statistically significant differences were shown for other maternal and pregnancy outcomes: preterm births RR 0.99 (95% CI 0.96 to 1.02), miscarriage RR 0.90 (95% CI 0.79 to 1.02), maternal mortality RR 0.97 (95% CI 0.63 to 1.48), perinatal mortality RR 0.99 (95% CI 0.84 to 1.16), stillbirths RR 0.96 (95% CI 0.86 to 1.07) and neonatal mortality RR 1.01 (95% CI 0.89 to 1.15).A number of prespecified clinically important outcomes could not be assessed due to insufficient or non-available data. These include placental abruption, congenital anomalies including neural tube defects, premature rupture of membranes, neurodevelopmental delay, very preterm births, cost of supplementation, side-effects of supplements, maternal well being or satisfaction, and nutritional status of children.

AUTHORS' CONCLUSIONS

Though multiple micronutrients have been found to have a significant beneficial impact on SGA and low birthweight babies, we still need more evidence to guide a universal policy change and to suggest replacement of routine iron and folate supplementation with a MMS. Future trials should be adequately powered to evaluate the effects on mortality and other morbidity outcomes. Trials should also assess the effect of variability between different combinations and dosages of micronutrients, keeping within the safe recommended levels. In regions with deficiency of a single micronutrient, evaluation of each micronutrient against a placebo in women already receiving iron with folic acid would be especially useful in justifying the inclusion of that micronutrient in routine antenatal care.

Vitamin A and carotenoids during pregnancy and maternal, neonatal and infant health outcomes: a systematic review and meta-analysis

Vitamin A (VA) deficiency during pregnancy is common in low-income countries and a growing number of intervention trials have examined the effects of supplementation during pregnancy on maternal, perinatal and infant health outcomes. We systematically reviewed the literature to identify trials isolating the effects of VA or carotenoid supplementation during pregnancy on maternal, fetal, neonatal and early infant health outcomes. Meta-analysis was used to pool effect estimates for outcomes with more than one comparable study. We used GRADE criteria to assess the quality of individual studies and the level of evidence available for each outcome. We identified 23 eligible trials of which 17 had suitable quality for inclusion in meta-analyses. VA or beta-carotene (βC) supplementation during pregnancy did not have a significant overall effect on birthweight indicators, preterm birth, stillbirth, miscarriage or fetal loss. Among HIV-positive women, supplementation was protective against low birthweight (<2.5 kg) [risk ratio (RR) = 0.79 [95% confidence interval (CI) 0.64, 0.99]], but no significant effects on preterm delivery or small-for-gestational age were observed. Pooled analysis of the results of three large randomised trials found no effects of VA supplementation on neonatal/infant mortality, or pregnancy-related maternal mortality (random-effects RR = 0.86 [0.60, 1.24]) although high heterogeneity was observed in the maternal mortality estimate (I(2) = 74%, P = 0.02). VA supplementation during pregnancy was found to improve haemoglobin levels and reduce anaemia risk (<11.0 g/dL) during pregnancy (random-effects RR = 0.81 [0.69, 0.94]), also with high heterogeneity (I(2) = 52%, P = 0.04). We found no effect of VA/βC supplementation on mother-to-child HIV transmission in pooled analysis, although some evidence suggests that it may increase transmission. There is little consistent evidence of benefit of maternal supplementation with VA or βC during pregnancy on maternal or infant mortality. While there may be beneficial effects for certain outcomes, there may also be potential for harm through increased HIV transmission in some populations.

Vitamin A intake and infection are associated with plasma retinol among pre-school children in rural Zambia

OBJECTIVE

To determine the prevalence of vitamin A deficiency, infection and adequacy of vitamin A intakes among Zambian children, and the contribution of dietary vitamin A and infection to vitamin A status.

DESIGN

A cross-sectional survey of vitamin A intakes by the 24 h recall method, vitamin A status by plasma retinol and the modified relative dose-response test, and infection by acute-phase proteins.

SETTING

Rural communities in Central and Eastern Provinces of Zambia.

SUBJECTS

Children 2-5 years of age.

RESULTS

The prevalence of vitamin A deficiency was 56 % by plasma retinol, 48 % with infection-adjusted plasma retinol and 22 % by the modified relative dose-response test. The majority of children (61 %) had a current infection. Vitamin A intakes were relatively high (331 to 585 μg retinol activity equivalents/d in the harvest/early post-harvest and late post-harvest seasons, respectively) and the prevalence of inadequate intakes was <1 % when compared with the Estimated Average Requirement (210 and 275 μg retinol activity equivalents/d for children aged 1-3 and 4-8 years, respectively). Elevated α-1-acid glycoprotein was negatively associated with plasma retinol (P < 0·0 0 1) and vitamin A intake was positively associated with plasma retinol (P < 0·05), but only when estimated assuming a 26:1 retinol equivalence for provitamin A from green and yellow vegetables.

CONCLUSIONS

Infection and vitamin A intakes were significant determinants of plasma retinol. We cannot conclude which indicator more accurately represents the true vitamin A status of the population. Reasons for the persistent high prevalence of vitamin A deficiency in the presence of adequate vitamin A intakes are unclear, but the high rates of infection may play a role.

Vitamin supplementation for preventing miscarriage

BACKGROUND

Miscarriage is a common complication of pregnancy that can be caused by a wide range of factors. Poor dietary intake of vitamins has been associated with an increased risk of miscarriage, therefore supplementing women with vitamins either prior to or in early pregnancy may help prevent miscarriage.

OBJECTIVES

The objectives of this review are to determine the effectiveness and safety of any vitamin supplementation, on the risk of spontaneous miscarriage, maternal adverse outcomes and fetal and infant adverse outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (21 June 2010).

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing one or more vitamins with either placebo, other vitamins, no vitamins or other interventions, prior to conception, periconceptionally or in early pregnancy (less than 20 weeks' gestation).

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trials for inclusion, extracted data and assessed trial quality.

MAIN RESULTS

We identified 28 trials assessing supplementation with any vitamin(s) starting prior to 20 weeks' gestation and reporting at least one primary outcome that was eligible for the review. Overall, the included trials involved 96,674 women and 98,267 pregnancies. Three trials were cluster randomised and combined contributed data for 62,669 women and 64,210 pregnancies in total. No significant differences were seen between women taking any vitamins compared with controls for total fetal loss (relative risk (RR) 1.04, 95% confidence interval (CI) 0.95 to 1.14), early or late miscarriage (RR 1.09, 95% CI 0.95 to 1.25) or stillbirth (RR 0.86, 95% CI 0.65 to 1.13) and most of the other primary outcomes, using fixed-effect models. Compared with controls, women given any type of vitamin(s) pre or peri-conception were more likely to have a multiple pregnancy (RR 1.38, 95% CI 1.12 to 1.70, three trials, 20,986 women).

AUTHORS' CONCLUSIONS

Taking any vitamin supplements prior to pregnancy or in early pregnancy does not prevent women experiencing miscarriage or stillbirth. However, women taking vitamin supplements may be more likely to have a multiple pregnancy. There is insufficient evidence to examine the effects of different combinations of vitamins on miscarriage, stillbirth or other maternal and infant outcomes.

Vitamin A supplementation during pregnancy for maternal and newborn outcomes

BACKGROUND

The World Health Organization recommends routine vitamin A supplementation during pregnancy or lactation in areas with endemic vitamin A deficiency (where night blindness occurs), based on the expectation that supplementation will improve maternal and newborn outcomes including mortality, morbidity and prevention of anaemia or infection.  

OBJECTIVES

To review the effects of supplementation of vitamin A, or one of its derivatives, during pregnancy, alone or in combination with other vitamins and micronutrients, on maternal and newborn clinical outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (15 July 2010).

SELECTION CRITERIA

All randomised or quasi-randomised trials, including cluster-randomised trials, evaluating the effect of vitamin A supplementation in pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all studies for inclusion and resolved any disagreement through discussion with a third person. We used pre-prepared data extraction sheets.

MAIN RESULTS

We examined 88 reports of 31 trials, published between 1931 and 2010, for inclusion in this review. We included 16 trials, excluded 14, and one is awaiting assessment.Overall when trial results are pooled, Vitamin A supplementation does not affect the risk of maternal mortality (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.55 to 1.10, 3 studies, Nepal, Ghana,UK ), perinatal mortality, neonatal mortality, stillbirth, neonatal anaemia, preterm birth or the risk of having a low birthweight baby. Vitamin A supplementation reduces the risk of maternal night blindness (risk ratio (RR) 0.70, 95% CI 0.60 to 0.82, 1 trial Nepal). In vitamin A deficient populations and HIV-positive women, vitamin A supplementation reduces maternal anaemia (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.43 to 0.94, 3 trials, Indonesia, Nepal,Tanzania ). There is evidence that vitamin A supplements may reduce maternal clinical infection (RR 0.37, 95% CI 0.18 to 0.77, 3 trials, South Africa, Nepal and UK).In HIV-positive women vitamin A supplementation given with other micronutrients was associated with fewer low birthweight babies (< 2.5 kg) in the supplemented group in one study (RR 0.67, CI 0.47 to 0.96).

AUTHORS' CONCLUSIONS

The pooled results of two large trials in Nepal and Ghana (with almost 95,000 women) do not currently suggest a role for antenatal vitamin A supplementation to reduce maternal or perinatal mortality. However the populations studied were probably different with regard to baseline vitamin A status and there were problems with follow-up of women. There is good evidence that antenatal vitamin A supplementation reduces maternal anaemia for women who live in areas where vitamin A deficiency is common or who are HIV-positive. In addition the available evidence suggests a reduction in maternal infection, but these data are not of a high quality.

Vitamin A deficiency increases hepcidin expression and oxidative stress in rat

OBJECTIVE

The interaction between vitamin A and iron status has been widely reported; however, the exact mechanism involved in this interaction has not been well characterized. The present study investigated the mechanism involved in tissue iron accumulation and changes in the oxidative status in vitamin A-deficient rats.

METHODS

Rats were treated with a control diet, a vitamin A-deficient diet, or a vitamin A/iron-deficient diet for 57 d. The animals were sacrificed; the blood, liver, and spleen were collected for biochemical analysis. Analysis of variance or Mann-Whitney tests were used to compare groups and Pearson's or Spearman's tests to investigate the bivariate correlation.

RESULTS

Vitamin A deficiency increased liver hepcidin mRNA and iron spleen concentrations; however, iron deficiency in vitamin A-deficient rats deeply inhibits liver hepcidin mRNA expression and significantly increases divalent metal transporter-1 mRNA levels. Liver ferroportin and hereditary hemochromatosis gene mRNA levels did not change in either treatment. In the vitamin A-deficient groups, liver carbonyl protein increased, whereas catalase and glutathione S-transferase activities decreased, suggesting that vitamin A protects the liver against protein oxidation. A significant positive correlation was found between lipid oxidative damage and iron concentration in the liver and spleen (r = 0.611, P = 0.007; r = 0.558, P = 0.025, respectively).

CONCLUSION

These results suggest that vitamin A maintains iron homeostasis by the modulation of liver hepcidin expression. The increase of lipid peroxidation in vitamin A deficiency seems to be iron dependent, whereas protein oxidation is not.

Determinants of anemia among preschool children in the Philippines

OBJECTIVE

Our objective was to identify the determinants of anemia among rural Filipino children aged 12-71 months.

METHODS

A cross-sectional survey was conducted among 2090 preschool children from 8 rural villages in Cebu, an area non-endemic for malaria and schistosomiasis. Hemoglobin (Hb) concentration was determined using a HemoCue hemoglobinometer and zinc protoporphyrin (ZPP) concentration was measured with a hematofluorometer. A 3-day non-consecutive 24-hour food recall interview with the child's primary caregiver was done to estimate the child's dietary intake. Stool analysis for presence of soil-transmitted helminths was performed through a concentration technique. A separate interview on household socio-economic status with the child's primary caregiver was conducted.

RESULTS

Mean Hb concentration was 12.0 g/dL (SD 1.3). 16.1% were anemic. Age and sex had a significant interaction in their effect on Hb concentration. Females had higher Hb concentration between 12 to 23 months of age. Hb levels equalize between the 2 genders at around 24 months and increase with similar increments until 71 months of age. All dietary parameters improved Hb concentration with increasing intake. In the multiple regression, however, only the index for bioavailable iron and vitamin C intakes remained independent factors. None of the helminths or combination of helminths had significant effects on Hb concentration. Among the socio-economic variables, maternal educational attainment and water supply were significant independent factors. Mean ZPP concentration was 72.07 (SD 46.45) and 30.8% were iron deficient. As with Hb concentration, age and sex had a significant interaction in their effect on ZPP concentration, with females having lower ZPP levels before 24 months of age. Bioavailable iron (animal iron + 0.3*plant iron) had a significant effect on ZPP concentration at levels of at least 15% of the iron requirement. This was seen even after controlling for multivitamin supplementation.

CONCLUSION

The control of anemia among preschoolers can be achieved through a combination of various nutritional interventions such as micronutrient supplementation, food fortification and nutrition education. Our findings emphasize the importance of a multi-sectoral approach to nutritional problems--the importance of empowering women (through engagement and education) and of maintaining a healthy physical environment (water and sanitation) are often peripheral concerns of nutritionists. Our study highlights the importance of supporting initiatives that address these issues not only for their core benefit, but also for the potential benefit to nutrition.

Poverty, obesity, and malnutrition: an international perspective recognizing the paradox

In the year 2000, multiple global health agencies and stakeholders convened and established eight tenets that, if followed, would make our world a vastly better place. These tenets are called the Millennium Development Goals. Most of these goals are either directly or indirectly related to nutrition. The United Nations has led an evaluation team to monitor and assess the progress toward achieving these goals until 2015. We are midway between when the goals were set and the year 2015. The first goal is to "eradicate extreme poverty and hunger." Our greatest responsibility as nutrition professionals is to understand the ramifications of poverty, chronic hunger, and food insecurity. Food insecurity is complex, and the paradox is that not only can it lead to undernutrition and recurring hunger, but also to overnutrition, which can lead to overweight and obesity. It is estimated that by the year 2015 noncommunicable diseases associated with overnutrition will surpass undernutrition as the leading causes of death in low-income communities. Therefore, we need to take heed of the double burden of malnutrition caused by poverty, hunger, and food insecurity. Informing current practitioners, educators, and policymakers and passing this information on to future generations of nutrition students is of paramount importance.

One-time graded doses of vitamin A to weanling piglets enhance hepatic retinol but do not always prevent vitamin A deficiency

BACKGROUND

Vitamin A supplements are administered to infants in developing countries at immunization contacts; doses of 50000 IU vitamin A are recommended. Doses of 100000 IU are given to children aged 0.5-1 y. The efficacy of these doses has not been adequately determined.

OBJECTIVE

We aimed to quantify liver vitamin A after the administration of vitamin A doses to piglets. Piglets are a good model for infants because of their similar size, gastrointestinal anatomy, and vitamin A requirements.

DESIGN

Castrated male piglets born to sows fed a vitamin A-depleted diet throughout 1 (parity A) or 3 (parity B) pregnancy and lactation cycles were randomly assigned to receive 1 of 4 oral vitamin A doses (ie, 0, 25000, 50000, or 100000 IU) at weaning (days 9-14). A vitamin A-depleted diet was fed until the piglets were killed on day 10. Serum retinol was measured on days 1, 2, 4, 7, and 10. The modified relative dose response was measured before supplementation and at the time of killing, and liver vitamin A concentration was measured.

RESULTS

In both parities, 25000 IU did not result in a mean liver retinol reserve > 0.07 micromol/g liver (the deficiency cutoff). The 50000-IU dose increased mean reserves above 0.07 micromol/g only in parity A. Liver vitamin A reserves with the 100000-IU treatment were only 5% above those with the 50000-IU treatment. The modified relative dose-response test reflected differences in liver vitamin A stores in parity B, and the 0-IU group differed significantly from the 100000-IU group (P = 0.011).

CONCLUSION

This piglet model suggests that, for supplementation to infants <6 mo old, a 50000-IU dose is likely to be more efficacious in mitigating deficiency than is a 25000-IU dose.

Vitamin A liver store: a case-control study

The present study aims to assess the vitamin A liver store in individuals who died of several causes and to compare them with those who died of violent causes. A case-control study was performed with 60 individuals, where 30 died of violent causes (control) and 30 of other causes (cardiovascular diseases, infections, other chronic degenerative diseases, several causes). According to the cause of death, the mean retinol from liver stores was 281.5 +/- 63.50 mg/g for individuals who died of violent causes--a significantly higher amount (P < 0.05) than those observed in the other group (105.4 +/- 87.54 mg/g by cardiovascular diseases, 88.1 +/-78.03 mg/g by infections, 162.4 +/- 119.19 mg/g by other chronic degenerative diseases and 205.5 + 126.63 mg/g by several causes). The highest prevalence of low vitamin A was observed in individuals who died of infections and cardiovascular diseases, which emphasizes the role of vitamin A in these pathological processes.

Supplementation with iron and riboflavin enhances dark adaptation response to vitamin A-fortified rice in iron-deficient, pregnant, nightblind Nepali women

BACKGROUND

Nightblindness affects 16-52% of pregnant women in areas of Nepal and in some cases persists after vitamin A treatment. Iron and riboflavin affect vitamin A utilization and photoreceptor function, respectively, and pilot data in the study population showed a high prevalence of iron and riboflavin deficiencies.

OBJECTIVE

The objective was to assess the effect of supplemental iron and riboflavin on pupillary threshold (PT) and plasma retinol in nightblind, pregnant Nepali women given vitamin A-fortified rice.

DESIGN

Nightblind pregnant women were randomly assigned to receive, 6 d/wk under supervision for 6 wk, a vitamin A-fortified rice curry dish providing 850 microg retinal activity equivalents/d with either a 30-mg Fe and 6-mg riboflavin (FeR + VA) capsule or a placebo control (VA only) capsule. Hemoglobin, erythrocyte riboflavin, and plasma ferritin and retinol were measured before and after the intervention. Dark adaptation was assessed by PT score.

RESULTS

Women who were iron deficient at baseline (n=38) had significantly greater improvement in PT score with iron and riboflavin supplementation than without (P=0.05). Iron and riboflavin supplements significantly reduced the prevalences of riboflavin deficiency (from 60% to 6%; P<0.0001), iron deficiency anemia (from 35% to 15%; P<0.007), and abnormal PT (from 87% to 30%; P<0.05) from baseline. Mean increases in erythrocyte riboflavin (P<0.0001) and plasma ferritin (P=0.01) were greater in the FeR + VA group than in the VA only group.

CONCLUSIONS

Iron deficiency may limit the efficacy of vitamin A to normalize dark adaptation in pregnant Nepali women. Further studies are needed to assess the effect of simultaneous delivery of iron and vitamin A for the treatment of nightblindness.

Interação entre vitamina A e ferro em diferentes grupos populacionais

A interação entre ferro e vitamina A tem sido alvo de pesquisas científicas, visto que existem questões ainda pouco esclarecidas. Através de um levantamento bibliográfico, mediante consulta à base de dados Medline da National Library of Medicine, Estados Unidos da America, foram selecionadas publicações que tratavam sobre a interação entre ferro e vitamina A em seres humanos, a partir da década de 80 até o ano de 2003. As palavras chave utilizadas no levantamento bibliográfico foram "ferro", "vitamina A" e "anemia" e seus correspondentes em língua inglesa. Os resultados indicam que existe correlação entre os indicadores do estado nutricional de vitamina A e ferro em crianças, adolescentes e gestantes e que a fortificação e suplementação com vitamina A têm efeito favorável no metabolismo do ferro nesses grupos. Entretanto, ainda são necessários mais estudos para se conseguir estabelecer quais as doses e o período necessário de suplementação de vitamina A para beneficiar significantemente o estado nutricional de ferro. Os mecanismos que explicam a associação entre vitamina A e ferro ainda são desconhecidos, entretanto alguns autores atribuem essa interação ao fato de a vitamina A beneficiar a eritropoese, prevenir infecções ou melhorar a absorção de ferro.

Multiple-micronutrient supplementation for women during pregnancy

BACKGROUND

Multiple-micronutrient deficiencies often coexist in low- to middle-income countries. They are exacerbated in pregnancy due to the increased demands, leading to potentially adverse effects on the mother. Substantive evidence regarding the effectiveness of multiple-micronutrient supplements (MMS) during pregnancy is not available.

OBJECTIVES

To evaluate the benefits to mother and infant of multiple-micronutrient supplements in pregnancy and assess the risk of excess supplementation and potential adverse interactions between micronutrients.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 December 2005).

SELECTION CRITERIA

All prospective randomised controlled trials evaluating micronutrient supplementation during pregnancy and its effects on the pregnancy outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the data.

MAIN RESULTS

Nine trials (15,378 women) are included. When compared with supplementation of two or less micronutrients or no supplementation or a placebo, multiple-micronutrient supplementation resulted in a statistically significant decrease in the number of low birthweight babies (relative risk (RR) 0.83; 95% confidence interval (CI) 0.76 to 0.91), small-for-gestational-age babies (RR 0.92; 95% CI 0.86 to 0.99) and in maternal anaemia (RR 0.61; CI 0.52 to 0.71). However, these differences lost statistical significance when multiple-micronutrient supplementation was compared with iron folic acid supplementation alone. No statistically significant differences were shown for the outcomes of preterm births and perinatal mortality in any of the comparisons. A number of prespecified clinically important outcomes could not be assessed due to insufficient or non-available data from the included trials. These include placental abruption, congenital anomalies including neural tube defects, premature rupture of membranes, pre-eclampsia, miscarriage, maternal mortality, neurodevelopmental delay, very preterm births, cost of supplementation, side-effects of supplements, maternal wellbeing or satisfaction and nutritional status of children.

AUTHORS' CONCLUSIONS

The evidence provided in this review is insufficient to suggest replacement of iron and folate supplementation with a multiple-micronutrient supplement. A reduction in the number of low birthweight and small-for-gestational-age babies and maternal anaemia has been found with a multiple-micronutrient supplement against supplementation with two or less micronutrients or none or a placebo, but analyses revealed no added benefit of multiple-micronutrient supplements compared with iron folic acid supplementation. These results are limited by the small number of studies available. There is also insufficient evidence to identify adverse effects and to say that excess multiple-micronutrient supplementation during pregnancy is harmful to the mother or the fetus. Further research is needed to find out the beneficial maternal or fetal effects and to assess the risk of excess supplementation and potential adverse interactions between the micronutrients.

Prevalence of infant Vitamin A deficiency and undernutrition in the Republic of Congo

OBJECTIVES

A representative sample of 5722 pre-school children living in rural and urban areas of the Congo was examined between July and September 1999 for assessing Vitamin A deficiency.

METHODS

Using a randomized two-level cluster sampling method, 190 clusters of 30 children aged from 6 months to 6 years were selected in order to assess the prevalence of active xerophthalmia (night blindness and/or Bitot spots). Concurrently, the children's height and weight were determined. A semi-quantitative seven-day dietary questionnaire was applied to the mothers of 5722 children to estimate the latter's consumption of Vitamin A rich foodstuffs. The prevalence of biochemical deficiency was assessed based on the serum retinol concentrations analyzed in dried blood spots from a sub-sample of 300 children living in the Pointe-Noire area.

RESULTS

Among the 5722 children studied, 0.7% were found to suffer from night blindness and 7.7% had Bitot spots. The weekly intake of Vitamin A rich foods was estimated in 5722 children. Our data suggest that Vitamin A rich food consumption was lower in rural zones than in urban area according to the food frequency method threshold values. The serum retinol levels were lower than 10 microg/dl in 18% (95% confidence interval [C.I.]: 13.7, 22.3) [8.04+/-2.87 microg/dl] and less than 20 microg/dl in 49% (95% C.I.: 43.4, 54.6) [15.05+/-2.76 microg/dl] of the 300 studied children. We have established a significant relation between mean serum retinol levels and high rate of Vitamin A food intake (chi-square=59.64, 2 d.d.l., p<0.05) in the sample studied. The mean serum retinol concentrations did not differ significantly between the various Z-scores of weight for age (W/A) and height for age (H/A) patterns. But children with a weight for height (W/H) ratio below -2 standard deviation (S.D.) had significantly lower serum retinol values [9.33+/-1.3 microg/dl] than those with a W/H ratio greater than or equal to -2S.D. [10.82+/-4.84 microg/dl].

CONCLUSION

These data suggest that Vitamin A deficiency is still a serious public health problem in rural areas of the Congo in which this study was carried out.

Anaemia, iron deficiency and vitamin A status among school-aged children in rural Kazakhstan

OBJECTIVES

To investigate the prevalence of anaemia and iron deficiency and vitamin A status among school-aged children in rural Kazakhstan and identify factors associated with anaemia in this population.

DESIGN

A cross-sectional design.

SETTING

School-aged children in rural Kazakhstan.

SUBJECTS

Socio-economic and anthropometric information was collected from 159 school-aged children living in the Kzyl-Orda region of Kazakhstan. Blood samples were collected and the concentrations of haemoglobin (Hb), serum iron, serum ferritin (SF), erythrocyte protoporphyrin (EP), serum retinol and beta-carotene, total iron binding capacity (TIBC), transferrin saturation (TS) and other haematological indices were measured.

RESULTS

Among the 159 children, the prevalence of anaemia and iron deficiency defined by the multiple criteria model (SF, TS and EP) was 27% and 13%, respectively. Nine per cent had iron-deficiency anaemia and 21% had serum retinol value < 1.05 micromol l(-1). Mean SF and serum iron concentrations and TS were significantly lower in anaemic children than in their non-anaemic peers, while TIBC and EP were significantly higher in children with anaemia. Hb was significantly correlated with serum iron and retinol concentrations. Serum retinol and SF concentrations and mean corpuscular volume were significantly correlated with Hb by multiple regression analysis.

CONCLUSIONS

Anaemia among school-aged children in rural Kazakhstan appears to be related to iron indices and vitamin A status.

Vitamin supplementation for preventing miscarriage

BACKGROUND

Miscarriage is a common complication of pregnancy that can be caused by a wide range of factors. Poor dietary intake of vitamins has been associated with an increased risk of miscarriage, therefore supplementing women with vitamins either prior to or in early pregnancy may help prevent miscarriage.

OBJECTIVES

The objectives of this review are to determine the effectiveness and safety of any vitamin supplementation, on the risk of spontaneous miscarriage, maternal adverse outcomes and fetal and infant adverse outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (8 September 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003) and MEDLINE (1966 to May 2003), Current Contents (1998 to May 2003) and EMBASE (1980 to May 2003).

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing one or more vitamins with either placebo, other vitamins, no vitamins or other interventions, prior to conception, periconceptionally or in early pregnancy (less than 20 weeks' gestation).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted data and assessed trial quality.

MAIN RESULTS

We identified seventeen trials assessing supplementation with any vitamin(s) starting prior to 20 weeks' gestation and reporting at least one primary outcome that were eligible for the review. Overall, the included trials involved 35,812 women and 37,353 pregnancies. Two trials were cluster randomised and contributed data for 20,758 women and 22,299 pregnancies in total. No difference was seen between women taking any vitamins compared with controls for total fetal loss (relative risk (RR) 1.05, 95% confidence interval (CI) 0.95 to 1.15), early or late miscarriage (RR 1.08, 95% CI 0.95 to 1.24) or stillbirth (RR 0.85, 95% CI 0.63 to 1.14) and most of the other primary outcomes, using fixed-effect models. For the other primary outcomes, women given any type of vitamin(s) compared with controls were less likely to develop pre-eclampsia (RR 0.68, 95% CI 0.54 to 0.85, four trials, 5580 women) and more likely to have a multiple pregnancy (RR 1.38, 95% CI 1.12 to 1.70, three trials, 20,986 women).

AUTHORS' CONCLUSIONS

Taking vitamin supplements, alone or in combination with other vitamins, prior to pregnancy or in early pregnancy, does not prevent women experiencing miscarriage or stillbirth. However, women taking vitamin supplements may be less likely to develop pre-eclampsia and more likely to have a multiple pregnancy.

Validity of the relative-dose-response test and the modified-relative-dose-response test as indicators of vitamin A stores in liver

BACKGROUND

Our group and many others have used the relative-dose-response (RDR) test and the modified-RDR (MRDR) test as proxy indicators of liver stores of vitamin A. However, we have become concerned about the validity of these indicators.

OBJECTIVE

Simulation models were used to assess effects of random variations in serum retinol concentration on the RDR and to assess effects of group differences in serum retinol concentration on the distribution of RDR and MRDR values.

DESIGN

Random and independent samples were drawn from normally distributed, computer-generated numbers whose distributions simulated serum concentrations of retinol and 3,4-didehydroretinol as obtained from published reports. The resulting data sets were used to compute surrogate RDR or MRDR values. In model 1, the relation between serum concentrations of retinol and RDR was examined within a fictitious population. In models 2 and 3, fictitious populations with different distributions of serum retinol concentration were compared with respect to their RDR and MRDR values.

RESULTS

Simulated RDR values and serum retinol concentrations were negatively related. Models 2 and 3 showed that group differences in serum retinol concentrations necessarily produced group differences in mean RDR or MRDR values. A mathematical artifact may explain the negative relation reported between MRDR and serum retinol concentration, and it dictates that this relation will necessarily vary between populations with different degrees of vitamin A deficiency.

CONCLUSION

A continued search for alternative blood indicators of liver stores of vitamin A is needed.

Vitamin A status and hemoglobin concentrations are improved in Indonesian children with vitamin A and deworming interventions

OBJECTIVE

Anemia is a major public health problem caused by multiple factors. Vitamin A (VA) depletion can affect hemoglobin concentration (Hb). This study investigated the improvement in Hb and VA status in preschool Indonesian children following supplementation with 210 micromol VA and deworming with 400 mg albendazole.

SUBJECTS AND DESIGN

Indonesian children (n = 131) infected with Ascaris lumbricoides and/or Trichuris trichiura were enrolled. The children were grouped by length of time since receiving 210 micromol VA through the local health system. Group 1 (VA administered > or = 4 month before baseline) included 51 children with Ascaris and 29 children with Trichuris. Group 2 had received VA < or = 1 month of baseline from the local health post and included 51 children.

INTERVENTION AND METHODS

Immediately following baseline Hb and VA status assessment (modified relative dose response (MRDR) test), Group 1 children were given 210 micromol VA and 400 mg albendazole. Group 2 were randomized to be dewormed either 1 week before, at the same time or 1 week after baseline MRDR and Hb measures. Follow-up assessment was 3-4 weeks after baseline.

RESULTS

VA status in Group 1 significantly improved in children with either Ascaris (P < 0.0001) or Trichuris (P = 0.028). Although the prevalence of anemia declined, the improvement in Hb was not significant (P = 0.08). In Group 2, improvement in VA status from the VA delivered through the public health system was maintained for more than 1 month. Hb improved (P = 0.0037) and this improvement appeared to be associated with the length of time between deworming and follow-up assessments.

CONCLUSION

Public health supplementation programs to improve VA status may also increase Hb concentrations and decrease anemia prevalence, especially when linked to deworming.

SPONSORSHIP

These studies were supported by the Thrasher Research Fund, SmithKline Beecham and Hatch-Wisconsin Agricultural Experiment Station number WIS04533.

Assessing vitamin A status: past, present and future

Xerophthalmia classification was traditionally used to identify populations with vitamin A deficiency. Currently, night blindness and dark adaptometry have been proposed as population assessment methods. While eye signs and function tests are still used in areas where vitamin A deficiency is severe, a subclinical vitamin A deficiency is more prevalent. Serum and breast milk retinol concentrations are used to identify vitamin A deficiency risk. However, in healthy individuals, serum retinol concentrations are homeostatically controlled and do not begin to decline until liver reserves of vitamin A are dangerously low. Moreover, serum retinol and retinol binding protein (RBP) concentrations fall during times of infection. The RBP:transthyretin ratio may help to determine if serum retinol concentrations are depressed by infection. Other methods better reflect liver reserves of vitamin A, the "gold" standard. The relative dose response and modified relative dose response tests involve giving a small dose of retinyl or dehydroretinyl ester, respectively, and determining a response in the serum at about 5 h. A new response test where retinoyl beta-glucuronide is administered and the degree of hydrolysis to retinoic acid is measured has been investigated. Unlike isotope dilution tests, the dose response tests lack utility in defining the total body reserve of vitamin A. The deuterated retinol isotope dilution test has been used in several different groups. Recently, a new isotope assay was developed using 13C-retinyl acetate and gas chromatography-combustion-isotope ratio mass spectrometry for analysis. Thus, having many choices of vitamin A assessment methods, laboratory sophistication and resources available will usually dictate which methods are chosen.

Vitamin A and infancy. Biochemical, functional, and clinical aspects

Vitamin A is a very intriguing natural compound. The molecule not only has a complex array of physiological functions, but also represents the precursor of promising and powerful new pharmacological agents. Although several aspects of human retinol metabolism, including absorption and tissue delivery, have been clarified, the type and amounts of vitamin A derivatives that are intracellularly produced remain quite elusive. In addition, their precise function and targets still need to be identified. Retinoic acids, undoubtedly, play a major role in explaining activities of retinol, but, recently, a large number of physiological functions have been attributed to different retinoids and to vitamin A itself. One of the primary roles this vitamin plays is in embryogenesis. Almost all steps in organogenesis are controlled by retinoic acids, thus suggesting that retinol is necessary for proper development of embryonic tissues. These considerations point to the dramatic importance of a sufficient intake of vitamin A and explain the consequences if intake of retinol is deficient. However, hypervitaminosis A also has a number of remarkable negative consequences, which, in same cases, could be fatal. Thus, the use of large doses of retinol in the treatment of some human diseases and the use of megavitamin therapy for certain chronic disorders as well as the growing tendency toward vitamin faddism should alert physicians to the possibility of vitamin overdose.