Coexisting micronutrient deficiencies among Sri Lankan pre-school children: a community-based study

Prevalence of low vitamin D status in an urban district in Sri Lanka: a population-based study

BACKGROUND

Vitamin D deficiency (VDD) is conventionally associated with inadequate sunlight exposure. Ironically, recent evidence suggests a rising prevalence in urban areas of tropical regions like Sri Lanka, where comprehensive data are unavailable. This study aimed to estimate the prevalence of low vitamin D status in urban adults and its impact on serum calcium.

METHODS

A population-based cross-sectional study was conducted among 1260 adults aged 35-74 years, living in Colombo, the most urban district in Sri Lanka. They were recruited from 63 administrative divisions, using multi-stage, probability-proportionate-to-size, cluster sampling. Non-fasting venous blood was collected without tourniquet. Low vitamin D (< 30.0 ng/mL), VDD (< 20 ng/mL) and vitamin D insufficiency (20.0-29.9 ng/mL) were determined using chemiluminescence assay method, and serum calcium using Calcium Gen2 reagent.

RESULTS

Among the population (53.3% females; mean age = 51.8 years), the prevalence of low vitamin D was 93.9% (95% CI: 92.5-95.2). This was primarily due to VDD (67.5%; 95% CI: 64.9.0-70.1%), with some insufficiency (26.4%; 95% CI: 24.0-28.9%). Most VDD cases (53.9.0%) were 'mild' (10.0- < 20.0 ng/mL) in severity, with fewer 'moderate' (12.8%) and 'severe' (0.8%) cases. Prevalence of VDD was highest in females, aged 35-44-years, living in 'highly urban' areas and of Tamil ethnicity. Further, VDD showed a decreasing trend with older age groups, while it was significantly more prevalent in females than males (72.6% vs. 61.7%; p < 0.01), across all age groups. Low serum calcium levels were observed in 9.8% of adults with low vitamin D, compared to 22.4% with normal vitamin D, implying that there could be factors other than vitamin D in maintaining serum calcium levels.

CONCLUSIONS

Colombo District, representing urban settings in Sri Lanka faces a high prevalence of low vitamin D, primarily VDD, with higher rates in females, younger individuals and highly urban areas. These findings challenge assumptions about tropical regions being guaranteed of optimal vitamin D levels; and underscore the need for national vitamin D supplementation and food fortification programs, especially in high-risk urban settings in South Asian countries like Sri Lanka.

Dietary diversity and nutritional status of children attending early childhood development centres in Vhembe District, Limpopo province, South Africa

The present study assessed dietary diversity and anthropometric status of children attending early development centres in South Africa. In the Vhembe District of Limpopo province, South Africa, 273 children were conveniently chosen from 8 randomly selected early childhood development centres for a cross-sectional study. Data were gathered via a questionnaire administered by the interviewer in June 2021. Height, body weight and mid-upper arm circumference were measured to assess anthropometric status. A 24-h dietary recall was obtained to provide information on dietary diversity. The prevalence of underweight, wasting and stunting was 9, 4 and 26 %, respectively. More than half of the children had a low dietary diversity score, according to the Food and Agriculture Organization scoring system for children. Grains, roots, tubers, dairy products, other fruits and vegetables, and flesh-based foods were the highest consumed food groups. The lowest consumption was for eggs, vitamin A-rich fruits and vegetables, legumes and nuts. Height for age and weight for age were significantly associated with dietary diversity score, but not weight for height. Children who did not meet the reference value of greater than 4 for dietary diversity had a significant risk of being underweight (AOR 0⋅25, 95 % CI 0⋅08, 0⋅75) and stunted (AOR 0⋅32, 95 % CI 0⋅14, 0⋅74). The nutritional status of the children was impacted by a lack of adequate dietary diversity. Young children in rural areas need to receive a wide range of food to promote greater diversification of diets in order to diminish the risk of undernutrition.

Anemia in Sri Lanka: A Literature Review

Anemia is a global health problem. This paper reviews literature on the prevalence of anemia in Sri Lanka. We searched EBSCO (Elton Bryson Stephens Company), Cochrane Library, and Medline for articles on prevalence and molecular basis of anemia in Sri Lanka from January 2000 to May 2021. Forty articles were selected. Most of the studies were on prevalence of anemia among children and pregnant women. All the studies had restricted themselves to assess the contributing factors for anemia in limited age categories. Most articles had attempted to determine the overall prevalence of anemia and the contribution of iron deficiency to it. There were only a few studies on prevalence and molecular basis of hemoglobinopathies and even fewer on the prevalence of anemia of chronic disease. None of the studies had attempted to assess the national prevalence of red cell membranopathies and enzymopathies. The published data on prevalence of anemia in Sri Lanka are incomplete. This review emphasizes the value of a much broader survey on anemia covering all age categories including the elderly and conducting a national survey including anemia of chronic disease and on red cell membranopathies and enzymopathies in Sri Lanka.

Inadequate Vitamin C Intake and Intestinal Inflammation Are Associated with Multiple Micronutrient Deficiency in Young Children: Results from a Multi-Country Birth Cohort Study

Children living in resource-limited settings often suffer from multiple micronutrient deficiencies (MMD). However, there lacks evidence on the correlates of MMD in young children. We investigated the role of diets, water, sanitation and hygiene practice, enteric infections, and impaired gut health on MMD in children at 24 months of age using data from the multi-country MAL-ED birth cohort study. Co-existence of more than one micronutrient deficiency (e.g., anemia, iron, zinc, or retinol deficiency) was considered as MMD. We characterized intestinal inflammation by fecal concentrations of myeloperoxidase (MPO) and neopterin (NEO) measured in the non-diarrheal stool samples. Bayesian network analysis was applied to investigate the factors associated with MMD. A total of 1093 children were included in this analysis. Overall, 47.6% of the children had MMD, with the highest prevalence in Pakistan (90.1%) and lowest in Brazil (6.3%). MMD was inversely associated with the female sex [OR: 0.72, 95% CI: 0.54, 0.92]. A greater risk of MMD was associated with lower vitamin C intake [OR: 0.70, 95% CI: 0.48, 0.94] and increased fecal concentrations of MPO [OR: 1.31, 95% CI: 1.08, 1.51]. The study results imply the importance of effective strategies to ameliorate gut health and improve nutrient intake during the early years of life.

High burden of hypovitaminosis D among the children and adolescents in South Asia: a systematic review and meta-analysis

BACKGROUND

Vitamin D is vital for the growth and development of children. While deficiency and/or insufficiency of vitamin D among South Asian children are frequently reported in the literature, the lack of a meta-analysis has left its true extent poorly characterized. In this study, we aimed to conduct a systematic review and perform meta-analyses of the prevalence of hypovitaminosis D among the children of the South Asian countries.

METHODS

Two major electronic search engines (PubMed and Scopus) and one database (Google scholar) were used; original studies, conducted among South Asian children and adolescents and published between 1 January 2001 and 31 December 2019. A random-effect meta-analysis was also performed to calculate the pooled prevalence of hypovitaminosis D followed by subgroup analyses for countries and age groups.

RESULTS

After applying inclusion and exclusion criteria, a total of 41 studies with a total population size of 18,233 were finally selected. The overall prevalence of hypovitaminosis D was 61% [95% CI: 46% to 71%] with highly significant heterogeneity (I2 = 99.72%; p < 0.0001). The average level of serum vitamin D ranged from 5 ng/mL to 34 ng/mL, with a weighted mean of 19.15 ng/mL (weighted standard deviation 11.59 ng/mL). Country-wise analysis showed that hypovitaminosis D in Afghanistan was the highest [96.2%; 95% CI: 91% to 99%], followed by Pakistan [94%; 95% CI: 90% to 96%], India [64%; 95% CI: 46% to 79%], Bangladesh [35.48%; 95% CI: 32% to 39%], Nepal [35%; 95% CI: 1% to 83%], and Sri Lanka [25%; 95% CI: 16% to 36%]. Age group analyses revealed that hypovitaminosis D was most prevalent among neonates [85%; 95% CI: 76% to 91%], followed by school-going children [57%; 95% CI: 33% to 80%], and preschool children [55%; 95% CI: 35% to 75%].

CONCLUSION

This study generates quantitative evidence and specific extent of hypovitaminosis D in the South Asian countries as a public health concern. Being the first systematic review for this region, results from this study will create awareness and will facilitate adopting mitigation strategies by the policymakers and the governments to address this problem.

Micronutrient status and associated factors of adiposity in primary school children with normal and high body fat in Colombo municipal area, Sri Lanka

BACKGROUND

The prevalence of obesity and associated risk of chronic diseases are increasing among the paediatric population. The effectiveness of preventive measures and interventions are likely to improve when all factors which associate with obesity in a specific target group are considered. Currently such comprehensive data is unavailable for Sri Lankan children aged 8-9 years.

METHODS

This paper pertains to the data collected from August-2015 to November-2016 for a case-control study which included cases (high body fat) (N = 160; males-81) and controls (normal body fat) (N = 164; males-80) recruited from primary schools in the Colombo Municipal area. Anthropometry and body composition (Bioelectrical impedance analysis-BIA) were measured. Diet, physical activity and socio-demographic data were collected using validated interviewer administered questionnaires. Serum concentrations of vitamins A, D [25(OH)D], E, folate (serum and red blood cell-RBC), zinc (Zn), selenium (Se), copper (Cu), iron (Fe), magnesium (Mg), calcium (Ca), chromium (Cr), manganese (Mn), cobalt (Co), ferritin, leptin and high sensitivity C-reactive protein (hs-CRP) were assessed using fasting blood samples.

RESULTS

Cases were from higher socio-economic strata and spent significantly less time on physical activities, more time on sedentary behaviours and consumed higher energy compared to the controls. Cases from both genders had significantly lower levels of vitamin D [25 (OH)D], Fe and Mg (all p < 0.05) and higher levels of Cu and Ca (all p < 0.01) compared to controls. Higher levels of ferritin and Cr were seen among male (p < 0.001) and female (p > 0.05) cases compared to the controls. However, total serum folate levels were lower in male (p < 0.01) and female (p > 0.05) cases while the RBC folate levels were higher among male (p < 0.01) and female (p > 0.05) cases compared with controls. Vitamins A, E, Se, Mn and Co (p > 0.05) were not significantly different between groups. The inflammatory markers, both hs-CRP and leptin levels were higher among cases (p < 0.001) compared to the controls.

CONCLUSIONS

This study highlights higher socio-economic status, lower physical activity, more sedentary behaviours, higher energy intake and inconsistent distribution of micronutrients among the children with high body fat when compared with the control group. Increased levels of inflammatory markers indicate the presence of the risk of chronic inflammation in children with high body fat.

Vitamin D supplementation in obese Sri Lankan children: a randomized controlled trial

Background

Micronutrient deficiencies are identified among obese individuals. Vitamin D deficiency (VDD) is prevalent in obese children, and is hypothesized to cause insulin resistance and metabolic abnormalities. This study aimed to determine the effect of vitamin D supplementation on obesity and related metabolic abnormalities among obese Sri Lankan children with VDD.

Methods

A triple-blind randomized controlled trial was conducted among vitamin D deficient (< 20 ng/ml), obese children (n = 96), randomly allocated to three intervention arms - treatment arm receiving weekly vitamin D₂ 50,000 IU; supplementation arm receiving 2500 IU weekly and control arm, receiving placebo. Anthropometry, percentage fat mass (%FM) and blood pressure were assessed and fasting blood glucose, fasting insulin, lipid profile, aspartate transaminase (ALT), alanine transaminase (AST), vitamin D, parathyroid hormone (PTH) and hs-CRP and OGTT with 2-h random blood glucose and insulin was performed at baseline and after 24 weeks of treatment. Ethics Review Committee of Faculty of Medicine, University of Colombo approved the protocol.

Results

Waist circumference Z-score, %FM and serum calcium significantly improved across all three arms, ALT significantly improved in treatment and supplementation arms while, BMI Z-score, PTH and vitamin D significantly improved in the treatment arm. Biceps (p = 0.035) and subscapular (0.048) skin fold thickness, vitamin D (p = 0.004) and ALT (p = 0.012) significantly improved in the treatment arm.

Conclusions

A strict dietary and physical activity regimen could improve some of the anthropometric, body composition and metabolic profiles, but high dose vitamin D, enhances those improvements. Therefore high dose vitamin D seems to potentiate management outcomes of obese children with vitamin D deficiency.

Trial registration

The study was registered at the Sri Lanka Clinical Trials Registry (SLCTR/2015/017) on 12th September 2015 at https://slctr.lk/trials/slctr-2015-017.

Prevalence of vitamin D deficiency and its association with metabolic derangements among children with obesity

Background

It is known that obesity is associated with vitamin D deficiency and observational studies have shown vitamin D deficiency to be linked with the development of type 2 diabetes. There are no comprehensive data regarding vitamin D deficiency in children with obesity in Sri Lanka and the objective of the study was to assess the prevalence of Vitamin D deficiency and its association with metabolic derangements among children with obesity.

Methodology

Two hundred and two children between 5 and 15 years of age attending the obesity clinic Lady Ridgeway Hospital (LRH) were recruited excluding those having possible secondary causes for obesity. Blood was drawn after 12-h overnight fast for fasting blood glucose(FBG), lipid profile, serum insulin, alanine aminotransferase (ALT),aspartate aminotransferase(AST), Vitamin D, parathyroid hormone(PTH),high sensitivity C reactive protein(hs-CRP). Oral glucose tolerance test (OGTT) was done with 2 h random blood glucose. Anthropometry, blood pressure were measured, and body fat mass was assessed using bio-impedance.

Results

Vitamin D deficiency (< 20 ng/ml) was seen in 152(75.2%) children and 43(21.3%) had insufficient (20-30 ng/ml) levels. Skin fold thickness, fasting and post-glucose insulin, HOMA-IR, PTH, LDL, Serum cholesterol and hs-CRP showed statistically significant negative correlations with Vitamin D levels.

Conclusions

Vitamin D deficiency was significantly high in Sri Lankan children with obesity and showed significant negative correlations with indicators of insulin resistance and adiposity.

Zinc deficiency in children with Dengue viral infection

Zinc deficiency is highly prevalent in low-income countries, with dramatic consequences to child health, in particular by impairing the immune system resulting in infection. This cross-sectional study aimed to determine the prevalence of zinc deficiency in Thai children who were admitted to hospital with a diagnosis of the dengue viral infection. Standard cut-off values according to age, sex, time of blood collection, and fasting status were used to define zinc levels. 32 patients were included in the analysis: The mean age was 7.3 years, of whom 56.3% were males. 11 (34.4%) patients were diagnosed with dengue hemorrhagic fever and the remaining had dengue fever. The prevalence of zinc deficiency was 46.7%, with boys having a higher risk of zinc deficiency than girls (OR=7.3: 95%CI: 1.5-36.6). Fever duration and length of hospital stay were longer in children with zinc deficiency compared to those who had normal levels, albeit without a significant difference. The results of this study provide the rationale for larger studies that will better elucidate the relationship between zinc levels and the clinical outcomes of dengue disease.

Supplementation of micronutrients in children and food fortification initiatives in Sri Lanka: benefits versus risks

In recent decades, Sri Lanka has made substantial progress in reducing the burden of micronutrient deficiencies in children by the provision of vitamin A megadose and micronutrient supplementation programs for children of 6-23 months, along with universal iodization of salt. Consumption of voluntarily fortified foods by children was also considerably increased. The objective of our study here was to review such interventions, which are beneficial in childhood, and to assess the risk of toxicity due to excessive intakes of iron, vitamin A, and iodine. Our analysis was performed using data from two national micronutrient surveys, market surveys, and key informant interviews. Data on coverage, usage, and nutrient content of certain foods were compiled to gauge consumption of iron, vitamin A, and iodine among children. We found that the severity of anemia and vitamin A and iodine deficiencies declined from moderate-to-severe and that supplementation and fortification can lead to an excess of vitamin A that may cause toxicity, while iron and iodine deficiency appears to be no longer a public health concern in Sri Lanka. We recommend review and scaling back of national supplementation programs and monitoring of fortification initiatives to prevent micronutrient toxicity in the future.

Micronutrient Status in Sri Lanka: A Review

Micronutrients include vitamins, minerals and, trace elements that are required in minute quantities but play a vital role in normal human growth, development and physiological functioning. Micronutrient deficiencies, also known as hidden hunger, are a global issue, with particularly high prevalence rates in developing countries. Currently, Sri Lanka is experiencing the double burden of over- and undernutrition. This review describes the micronutrient status of Sri Lanka based on results of national surveys and related articles published from 2000. The available data suggest a higher prevalence of iron, zinc, calcium, folate, and vitamin A deficiencies. The prevalence of iodine deficiency has declined gradually following the implementation of a universal salt iodization program. Iron deficiency is the most common cause of anemia and low red blood cell indices. Females are more vulnerable to micronutrient deficiencies than males. The coexistence of multiple micronutrient deficiencies and concurrent macro- and micronutrient deficiencies is common. Studies have shown an association between micronutrient deficiencies and different demographic, socioeconomic, and dietary factors. Therefore, there is a need for comprehensive studies, nutritional policies, and nationwide intervention programs in Sri Lanka to improve the micronutrient status of the population.

A systematic review and meta-analysis of prevalence of vitamin D deficiency among adolescent girls in selected Indian states

BACKGROUND:

Vitamin D deficiency among adolescents is an emerging public health priority as adolescence marks a period of rapid growth and the onset of the reproductive phase. However, lack of national prevalence data and intervention strategies is of public health concern.

OBJECTIVE:

The objective of this study was to determine the pooled prevalence of vitamin D deficiency among adolescent girls in selected Indian states.

METHODS:

A systematic literature review was performed using three different search engines. The searches yielded nine eligible articles. Study quality was assessed for 10 different criteria. Meta-analysis was performed to estimate pooled prevalence of vitamin D deficiency among adolescent girls and to assess the heterogeneity among selected studies.

RESULTS:

A sample of n=1352 was used to study prevalence among adolescent girls. The random effects combined estimate for overall prevalence was 25.70% (95% CI 3.89-2137.9). High heterogeneity (tau²=1.71, I²=100%) was observed and seven out of nine studies showed low to moderate risk and two showed high risk of bias. The test for overall effect was observed to be Z=0.77 ( p=0.44).

CONCLUSIONS:

High prevalence of vitamin D deficiency among adolescent girls identifies the need to introduce screening of adolescents and introduce proven public-health interventions such as fortification of foods to address deficiency.

Is vitamin D deficiency a public health concern for low middle income countries? A systematic literature review

PURPOSE

Vitamin D deficiency has been receiving increasing attention as a potential public health concern in low and lower-middle income countries (LMICs), of which there are currently 83. We aimed to conduct a comprehensive systematic literature review (SLR) of available data on vitamin D status and prevalence of vitamin D deficiency in all 83 LMICs.

METHODS

We followed the general methodology for SLRs in the area of serum 25-hydroxyvitamin D. Highest priority was placed on identifying relevant population-based studies, followed by cross-sectional studies, and to a lesser extent case-control studies. We adopted the public health convention that a prevalence of vitamin D deficiency (serum 25-hydroxyvitamin D < 25/30 nmol/L) at > 20% in the entire population and/or at-risk population subgroups (infants, children, women of child-bearing age, pregnancy) constitutes a public health issue that may warrant intervention.

RESULTS

Our SLR revealed that of the 83 LMICs, 65% (n = 54 countries) had no published studies with vitamin D data suitable for inclusion. Using data from the remaining third, a number of LMICs had evidence of excess burden of vitamin D deficiency in one or more population subgroup(s) using the above convention (Afghanistan, Pakistan, India, Tunisia and Mongolia) as well as possibly other LMICs, albeit with much more limited data. Several LMICs had no evidence of excess burden.

CONCLUSION

Vitamin D deficiency is a public health issue in some, but certainly not all, LMICs. There is a clear need for targeting public health strategies for prevention of vitamin D deficiency in those LMICs with excess burden.

Micronutrient Deficiencies among Breastfeeding Infants in Tanzania

Infant mortality accounts for the majority of child deaths in Tanzania, and malnutrition is an important underlying cause. The objectives of this cross-sectional study were to describe the micronutrient status of infants in Tanzania and assess predictors of infant micronutrient deficiency. We analyzed serum vitamin D, vitamin B12, folate, and ferritin levels from 446 infants at two weeks of age, 408 infants at three months of age, and 427 mothers three months post-partum. We used log-Poisson regression to estimate relative risk of being deficient in vitamin D and vitamin B12 for infants in each age group. The prevalence of vitamin D and vitamin B12 deficiency decreased from 60% and 30% at two weeks to 9% and 13% at three months respectively. Yet, the prevalence of insufficiency at three months was 49% for vitamin D and 17% for vitamin B12. Predictors of infant vitamin D deficiency were low birthweight, urban residence, maternal education, and maternal vitamin D status. Maternal vitamin B12 status was the main predictor for infant vitamin B12 deficiency. The majority of infants had sufficient levels of folate or ferritin. Further research is necessary to examine the potential benefits of improving infants’ nutritional status through vitamin D and B12 supplements.

Factors associated with anemia among Sri Lankan primary school children in rural North Central Province

Background

Despite interventions, childhood anemia is still a major public health problem in low and middle income countries. Purpose of the present study is to determine factors associated with anemia among rural primary school children in Sri Lanka, a country undergoing rapid socioeconomic changes.

Methods

Multi stage cluster sampling was used to select 100 rural schools in NCP and a maximum of 50 children aged 60–131 months were enrolled from each school. Self-administered questionnaires were sent to parents. Anthropometric measurements and blood samples were obtained by trained investigators. Blood reports were analyzed in a commercial laboratory with external quality control measures.

Results

Total of 4412 children were included in the analysis. A Multiple regression was performed for hemoglobin. Only 4.2% of the change in hemoglobin could be explained by the model. District (p > 0.001), age (p > 0.001), timing of warm treatment(p = 0.026) and BMI for age (p = 0.002) uniquely contributed 1.12%, 1.19%, 0.13% and 0.26% to change in hemoglobin level respectively whereas, sex, monthly family income and frequency of meat and green leaf consumption didn’t contribute significantly.

Peripheral blood film analyses were available for 146 anemic children. Blood film was reported as normal in 19.9% while evidence of iron deficiency (18.5%), early iron deficiency (32.5%) and thalassemia trait with iron deficiency (29.5%) were reported in the rest.

Serum ferritin level was available for 417 children with hemoglobin less than 12 g/dl. Mean ferritin level was 63.7 microgram/l. Only 0.5% had depleted iron stores. A multiple regression was performed for serum ferritin and R² was 0.123 (p < 0.001). Area under the curve for serum ferritin and anemia was 0.436.

Conclusion

Anemia among rural primary school children in NCP cannot be well explained by routinely assessed socioeconomic characteristics which mainly provide clues to access for food. Commonly used anemia related investigations have low validity in detecting and explaining anemia in this population. Since behavioral factors have been shown to affect nutrition of younger children in Sri Lanka, studying weather behaviors are related to anemia in primary school children is important. Possible etiologies including but not limited to nutritional deficiencies need to be studied further.

Vitamin D Status in South Asian Populations - Risks and Opportunities

Human body acquires a significant amount of vitamin D by cutaneous synthesis under the action of sunlight and less is supplied through nutritional sources. Diversified sociocultural and economic determinants have been identified that limit the dietary intake of vitamin D and enough distribution of sunlight to maintain optimal levels of 25-hydroxyvitamin D (25(OH)D). Consequently, the world has witnessed a high prevalence of hypovitaminosis D in resource-limited South Asian countries. The purpose of this review is to provide a South Asian perspective of vitamin D status, critically examining India, Pakistan, Bangladesh, and Sri Lanka, and to shed light on potential determinants (latitude and season, sunshine exposure habits, age, gender, and genetic factors) leading to hypovitaminosis D among a variety of population groups. Literature search was carried out using bibliographic databases "PubMed," "Google Scholar," and "ScienceDirect.com." Serum 25(OH)D level, 20-50 nmol/L, was mainly taken as vitamin D deficiency, and determinants of low serum 25(OH)D concentration of the population under study were also considered. The review concludes that vitamin D deficiency is highly prevalent among South Asian populations and global efforts are needed to overcome hypovitaminosis in the region. In addition, dietary diversification, supplementation and fortification of foods with vitamin D, adequate exposure to sunlight, and consumption of animal foods were suggested as viable approaches to maintain 25(OH)D levels for optimal health.

Subclinical inflammation influences the association between vitamin A- and iron status among schoolchildren in Ghana

BACKGROUND AND OBJECTIVE

In resource-poor settings, micronutrient deficiencies such as vitamin A deficiency may co-exist with iron-deficiency. In this study we assessed the iron and vitamin A status of schoolchildren and the association between vitamin A and iron status.

METHODS

A cross-sectional design using the baseline data of a dietary intervention trial conducted among randomly selected 5-12 years old schoolchildren (n = 224) from 2 rural schools in northern Ghana. Hemoglobin (Hb), serum ferritin (SF) and serum transferrin receptor (sTfR) concentrations were used as measures of iron status. Retinol binding protein (RBP) was used as a measure of vitamin A status. Subclinical inflammation (SCI) was measured using C-reactive protein (CRP) and α1-acid glycoprotein (AGP) concentrations. We examined the cross-sectional association between vitamin A and iron status biomarkers with multiple linear regressions.

RESULTS

The proportions of schoolchildren with anemia (WHO criteria), iron-deficiency (ID, SF <15μg/l and/or sTfR >8.5mg/l) and iron-deficiency anemia (IDA, concurrent anemia and ID) were 63.8%, 68.3% and 46.4% respectively. Low or marginal vitamin A status (0.70 μmol/l ≤ RBP < 1.05μmol/l) was present in 48.2% while 37.5% of the schoolchildren had vitamin A deficiency (VAD, RBP <0.70 μmol/l). The prevalence of SCI as well as concurrent VAD and ID were 48.7% and 25% respectively. RBP was associated with Hb (β = 7.2, P = 0.05) but not SF (β = 20.7, P = 0.33) and sTfR concentration (β = 12.0, P = 0.63). In the presence of SCI, RBP was not associated with hemoglobin status but a significant positive association was observed among children without SCI.

CONCLUSIONS

The study shows that RBP is significantly associated with Hb concentration but not with SF and sTfR. The observed relationship between RBP and Hb is only significant in the absence of SCI.

Vitamin D deficiency in India: prevalence, causalities and interventions

Vitamin D deficiency prevails in epidemic proportions all over the Indian subcontinent, with a prevalence of 70%-100% in the general population. In India, widely consumed food items such as dairy products are rarely fortified with vitamin D. Indian socioreligious and cultural practices do not facilitate adequate sun exposure, thereby negating potential benefits of plentiful sunshine. Consequently, subclinical vitamin D deficiency is highly prevalent in both urban and rural settings, and across all socioeconomic and geographic strata. Vitamin D deficiency is likely to play an important role in the very high prevalence of rickets, osteoporosis, cardiovascular diseases, diabetes, cancer and infections such as tuberculosis in India. Fortification of staple foods with vitamin D is the most viable population based strategy to achieve vitamin D sufficiency. Unfortunately, even in advanced countries like USA and Canada, food fortification strategies with vitamin D have been only partially effective and have largely failed to attain vitamin D sufficiency. This article reviews the status of vitamin D nutrition in the Indian subcontinent and also the underlying causes for this epidemic. Implementation of population based educational and interventional strategies to combat this scourge require recognition of vitamin D deficiency as a public health problem by the governing bodies so that healthcare funds can be allocated appropriately.

Engineering complex metabolic pathways in plants

Metabolic engineering can be used to modulate endogenous metabolic pathways in plants or introduce new metabolic capabilities in order to increase the production of a desirable compound or reduce the accumulation of an undesirable one. In practice, there are several major challenges that need to be overcome, such as gaining enough knowledge about the endogenous pathways to understand the best intervention points, identifying and sourcing the most suitable metabolic genes, expressing those genes in such a way as to produce a functional enzyme in a heterologous background, and, finally, achieving the accumulation of target compounds without harming the host plant. This article discusses the strategies that have been developed to engineer complex metabolic pathways in plants, focusing on recent technological developments that allow the most significant bottlenecks to be overcome.

Zinc status in South Asian populations--an update

This article attempts to highlight the prevalence of zinc deficiency and its health and economic consequences in South Asian developing countries and to shed light on possible approaches to combating zinc deficiency. A computer-based search was performed on PubMed, Google, and ScienceDirect.com to retrieve relevant scientific literature published between 2000 and 2012. The search yielded 194 articles, of which 71 were culled. Studies were further screened on the basis of population groups, age and sex, pregnancy, and lactation. The most relevant articles were included in the review. Cutoffs for serum zinc concentration defined for zinc deficiency were 65 microg/dL for males and females aged < 10 years, 66 microg/dL for non-pregnant females, and 70 microg/dL for males aged > or = 10 years. Population segments from rural and urban areas of South Asian developing countries were included in the analysis. They comprised pregnant and lactating women, preschool and school children. The analysis reveals that zinc deficiency is high among children, pregnant and lactating women in India, Pakistan, Bangladesh, Sri Lanka, and Nepal. Diarrhoea has been established as a leading cause to intensify zinc deficiency in Bangladesh. Little has been done in Sri Lanka and Nepal to estimate the prevalence of zinc deficiency precisely. A substantial population segment of the South Asian developing countries is predisposed to zinc deficiency which is further provoked by increased requirements for zinc under certain physiological conditions. Supplementation, fortification, and dietary diversification are the most viable strategies to enhancing zinc status among various population groups.