Effect of a micronutrient fortificant mixture and 2 amounts of calcium on iron and zinc absorption from a processed food supplement

Calcium is a noncompetitive inhibitor of DMT1 on the intestinal iron absorption process: empirical evidence and mathematical modeling analysis

Iron absorption is a complex and highly controlled process where DMT1 transports nonheme iron through the brush-border membrane of enterocytes to the cytoplasm but does not transport alkaline-earth metals such as calcium. However, it has been proposed that high concentrations of calcium in the diet could reduce iron bioavailability. In this work, we investigate the effect of intracellular and extracellular calcium on iron uptake by Caco-2 cells, as determined by calcein fluorescence quenching. We found that extracellular calcium inhibits iron uptake by Caco-2 cells in a concentration-dependent manner. Chelation of intracellular calcium with BAPTA did not affect iron uptake, which indicates that the inhibitory effect of calcium is not exerted through intracellular calcium signaling. Kinetic studies performed, provided evidence that calcium acts as a reversible noncompetitive inhibitor of the iron transport activity of DMT1. Based on these experimental results, a mathematical model was developed that considers the dynamics of noncompetitive inhibition using a four-state mechanism to describe the inhibitory effect of calcium on the DMT1 iron transport process in intestinal cells. The model accurately predicts the calcein fluorescence quenching dynamics observed experimentally after an iron challenge. Therefore, the proposed model structure is capable of representing the inhibitory effect of extracellular calcium on DMT1-mediated iron entry into the cLIP of Caco-2 cells. Considering the range of calcium concentrations that can inhibit iron uptake, the possible inhibition of dietary calcium on intestinal iron uptake is discussed.

Dual-Fortified Lentil Products-A Sustainable New Approach to Provide Additional Bioavailable Iron and Zinc in Humans

BACKGROUND

Iron (Fe) and zinc (Zn) deficiencies are global health problems affecting 20% and 33% of the world's population, respectively. Lentil (Lens culinaris Medik.), part of the staple food supply in many countries, can be a potential vehicle for Fe and Zn fortification.

OBJECTIVE

We developed a dual-fortification protocol to fortify 3 milled lentil product types (LPTs) [red-football (RF), red-split (RS), and yellow-split (YS)], with NaFeEDTA and ZnSO4.H2O to increase the bioavailable content of Fe and Zn.

METHODS

Appropriate Fe and Zn doses were determined to fortify lentils based on RDAs. Relative Fe bioavailability (RFeB%) and phytic acid (PA) content were assessed using an in vitro Caco-2 cell bioassay and PA analysis, respectively. One-factor ANOVA determined the differences in colorimetric score; concentrations of Fe, Zn, and PA; and RFeB% among samples. The least significant difference was calculated with significance level set at P < 0.05.

RESULTS

Fe and Zn concentration and RFeB% increased and PA concentration decreased significantly in dual-fortified lentils. Dual-fortified lentil samples had higher RFeB% compared with Fe-fortified (single) samples in all 3 LPTs, whereas RFeB% decreased in Zn-fortified (single) RF and YS samples by 43.4% and 36%, respectively. The RF, RS, and YS samples, fortified with 16 mg Fe and 8 mg Zn/100 g of lentils, provided 27 mg Fe and 14 mg Zn, 28 mg Fe and 13.4 mg Zn, and 29.9 mg Fe and 12.1 mg Zn, respectively. RFeB% of RF, RS, and YS lentil samples increased by 91-307%, 114-522%, and 122-520%, respectively. Again, PA concentrations of RF, RS, and YS lentils were reduced by 0.63-0.53, 0.83-0.71, and 0.96-0.79 mg/g, respectively.

CONCLUSIONS

Dual-fortified lentil consumption can cost-effectively provide a significant part of the daily bioavailable Fe and Zn requirements of people with these 2 globally important micronutrient deficiencies.

Pengaruh Konsumsi Buah jeruk (Citrus reticulata) dan Suplementasi Zinc terhadap Kadar Glukosa Darah Puasa pada Wanita Diabetes Melitus Tipe 2

 Background: Patients with Diabetes Mellitus (DM) Type 2 are at risk of micronutrient loss related to metabolic diseases, one of them is zinc. It plays an important role since it affects the function of pancreatic cell β, insulin activities, glucose homeostasis and pathogenesis of DM. Low zinc levels are associated with higher complications of DM. One of the nutrients that helps absorbing zinc is organic acids such as citric acid and ascorbic acid contained in citrus fruits.Objective: to analyze the effect of citrus fruits (Citrus reticulata) and zinc supplements consumption on fasting blood glucose in women with DM Type 2.Method: This study was an experimental study using pretest and posttest method with control group. The subjects were 30 people with DM Type 2 in Prolanis club in three Puskesmas in Surabaya who had been selected using consecutive sampling, and divided into 2 groups, namely the treatment group that consumed 200 g of orange and 20 mg of zinc supplement per day and the control group that consumed only 20 mg zinc per day. Citrus fruits and zinc supplements were consumed daily for four weeks. Fasting blood glucose was analyzed using automatic chemistry analyzer. Data analysis included univariate analysis with Shapiro-Wilk and bivariate analysis with Independent t-test, Mann-Whitney and Paired t-testResults: Fasting blood glucose in the subjects consuming citrus fruits and zinc supplements was decreased by 16.67 mg/dl (from 155.87 mg/dl to 139.20 mg/dl) (p = 0.121), while the group with zinc consumption was decreased by 9.85 mg/dl (from 140.93 mg/dl to 131.13 mg/dl) (p = 0.095). The decrease in fasting blood glucose in both groups was not statistically significant.Conclusion: Consumption of citrus fruits and zinc supplements did not significantly reduce fasting blood glucose in women with DM Type 2. Further research is needed with a longer period of intervention to better reflect the changes in zinc metabolism related to blood glucose control.ABSTRAKLatar Belakang : Pasien Diabetes Mellitus (DM) Tipe 2 beresiko kehilangan zat gizi mikro terkait metabolik penyakitnya, salah satunya adalah zinc. Zinc berperan penting karena mempengaruhi fungsi sel β pankreas, aktifitas insulin, homeostasis glukosa dan patogenesis DM. Kadar zinc yang rendah terkait dengan komplikasi DM yang lebih tinggi. Salah satu zat gizi yang membantu penyerapan zinc adalah asam organik seperti asam sitrat dan asam askorbat yang terkandung dalam buah jeruk.Tujuan : Menganalisa pengaruh konsumsi buah jeruk (Citrus reticulata) dan suplementasi zinc terhadap kadar gula darah puasa wanita DM tipe 2.Metode : Rancangan berupa quasi eksperimental dengan metode pretest and posttest with control group. Jumlah subjek 30 orang wanita DM tipe 2 anggota klub Prolanis di 3 Puskesmas di Kota Surabaya yang dipilih secara consecutive sampling, terbagi dalam 2 kelompok yaitu kelompok perlakuan yang mengkonsumsi 200 gram jeruk dan suplementasi zinc 20 mg/hari serta kelompok kontrol hanya mengkonsumsi zinc 20 mg/hari. Intervensi dilakukan 4 minggu. Gula darah puasa dianalisa menggunakan automatic chemistry analizer. Analisis data meliputi univariat dengan Shapiro-Wilk, analisa bivariat meliputi Independent t-test dan Mann-Whitney.Hasil : Meskipun rata-rata penurunan gula darah puasa sebesar 16,67 mg/dl pada subjek yang mengkonsumsi jeruk dan suplementasi zinc (p=0,121), namun tidak signifikan secara statistik.Kesimpulan : Konsumsi buah jeruk dan suplementasi zinc tidak signifikan menurunkan gula darah puasa wanita DM Tipe 2. Diperlukan penelitian lanjutan dengan jangka waktu intervensi yang lebih lama.

Food fortification with multiple micronutrients: impact on health outcomes in general population

BACKGROUND

Vitamins and minerals are essential for growth and maintenance of a healthy body, and have a role in the functioning of almost every organ. Multiple interventions have been designed to improve micronutrient deficiency, and food fortification is one of them.

OBJECTIVES

To assess the impact of food fortification with multiple micronutrients on health outcomes in the general population, including men, women and children.

SEARCH METHODS

We searched electronic databases up to 29 August 2018, including the Cochrane Central Register of Controlled Trial (CENTRAL), the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register and Cochrane Public Health Specialised Register; MEDLINE; Embase, and 20 other databases, including clinical trial registries. There were no date or language restrictions. We checked reference lists of included studies and relevant systematic reviews for additional papers to be considered for inclusion.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-RCTs, quasi-randomised trials, controlled before-after (CBA) studies and interrupted time series (ITS) studies that assessed the impact of food fortification with multiple micronutrients (MMNs). Primary outcomes included anaemia, micronutrient deficiencies, anthropometric measures, morbidity, all-cause mortality and cause-specific mortality. Secondary outcomes included potential adverse outcomes, serum concentration of specific micronutrients, serum haemoglobin levels and neurodevelopmental and cognitive outcomes. We included food fortification studies from both high-income and low- and middle-income countries (LMICs).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened, extracted and quality-appraised the data from eligible studies. We carried out statistical analysis using Review Manager 5 software. We used random-effects meta-analysis for combining data, as the characteristics of study participants and interventions differed significantly. We set out the main findings of the review in 'Summary of findings' tables, using the GRADE approach.

MAIN RESULTS

We identified 127 studies as relevant through title/abstract screening, and included 43 studies (48 papers) with 19,585 participants (17,878 children) in the review. All the included studies except three compared MMN fortification with placebo/no intervention. Two studies compared MMN fortification versus iodised salt and one study compared MMN fortification versus calcium fortification alone. Thirty-six studies targeted children; 20 studies were conducted in LMICs. Food vehicles used included staple foods, such as rice and flour; dairy products, including milk and yogurt; non-dairy beverages; biscuits; spreads; and salt. Fourteen of the studies were fully commercially funded, 13 had partial-commercial funding, 14 had non-commercial funding and two studies did not specify the source of funding. We rated all the evidence as of low to very low quality due to study limitations, imprecision, high heterogeneity and small sample size. When compared with placebo/no intervention, MMN fortification may reduce anaemia by 32% (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.56 to 0.84; 11 studies, 3746 participants; low-quality evidence), iron deficiency anaemia by 72% (RR 0.28, 95% CI 0.19 to 0.39; 6 studies, 2189 participants; low-quality evidence), iron deficiency by 56% (RR 0.44, 95% CI 0.32 to 0.60; 11 studies, 3289 participants; low-quality evidence); vitamin A deficiency by 58% (RR 0.42, 95% CI 0.28 to 0.62; 6 studies, 1482 participants; low-quality evidence), vitamin B2 deficiency by 64% (RR 0.36, 95% CI 0.19 to 0.68; 1 study, 296 participants; low-quality evidence), vitamin B6 deficiency by 91% (RR 0.09, 95% CI 0.02 to 0.38; 2 studies, 301 participants; low-quality evidence), vitamin B12 deficiency by 58% (RR 0.42, 95% CI 0.25 to 0.71; 3 studies, 728 participants; low-quality evidence), weight-for-age z-scores (WAZ) (mean difference (MD) 0.1, 95% CI 0.02 to 0.17; 8 studies, 2889 participants; low-quality evidence) and weight-for-height/length z-score (WHZ/WLZ) (MD 0.1, 95% CI 0.02 to 0.18; 6 studies, 1758 participants; low-quality evidence). We are uncertain about the effect of MMN fortification on zinc deficiency (RR 0.84, 95% CI 0.65 to 1.08; 5 studies, 1490 participants; low-quality evidence) and height/length-for-age z-score (HAZ/LAZ) (MD 0.09, 95% CI 0.01 to 0.18; 8 studies, 2889 participants; low-quality evidence). Most of the studies in this comparison were conducted in children. Subgroup analyses of funding sources (commercial versus non-commercial) and duration of intervention did not demonstrate any difference in effects, although this was a relatively small number of studies and the possible association between commercial funding and increased effect estimates has been demonstrated in the wider health literature. We could not conduct subgroup analysis by food vehicle and funding; since there were too few studies in each subgroup to draw any meaningful conclusions. When we compared MMNs versus iodised salt, we are uncertain about the effect of MMN fortification on anaemia (R 0.86, 95% CI 0.37 to 2.01; 1 study, 88 participants; very low-quality evidence), iron deficiency anaemia (RR 0.40, 95% CI 0.09 to 1.83; 2 studies, 245 participants; very low-quality evidence), iron deficiency (RR 0.98, 95% CI 0.82 to 1.17; 1 study, 88 participants; very low-quality evidence) and vitamin A deficiency (RR 0.19, 95% CI 0.07 to 0.55; 2 studies, 363 participants; very low-quality evidence). Both of the studies were conducted in children. Only one study conducted in children compared MMN fortification versus calcium fortification. None of the primary outcomes were reported in the study. None of the included studies reported on morbidity, adverse events, all-cause or cause-specific mortality.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that MMN fortification when compared to placebo/no intervention may reduce anaemia, iron deficiency anaemia and micronutrient deficiencies (iron, vitamin A, vitamin B2 and vitamin B6). We are uncertain of the effect of MMN fortification on anthropometric measures (HAZ/LAZ, WAZ and WHZ/WLZ). There are no data to suggest possible adverse effects of MMN fortification, and we could not draw reliable conclusions from various subgroup analyses due to a limited number of studies in each subgroup. We remain cautious about the level of commercial funding in this field, and the possibility that this may be associated with higher effect estimates, although subgroup analysis in this review did not demonstrate any impact of commercial funding. These findings are subject to study limitations, imprecision, high heterogeneity and small sample sizes, and we rated most of the evidence low to very low quality. and hence no concrete conclusions could be drawn from the findings of this review.

Inhibition of iron absorption by calcium is modest in an iron-fortified, casein- and whey-based drink in Indian children and is easily compensated for by addition of ascorbic acid

BACKGROUND

Calcium inhibits and ascorbic acid (AA) enhances iron absorption from iron-fortified foods. Absorption efficiency depends on iron status, although the interaction is unclear.

OBJECTIVE

We investigated the ability of AA to overcome calcium-induced inhibition of iron absorption in children differing in iron status.

METHODS

The effect of calcium (0, 100, and 200 mg/test meal) on iron absorption in the absence and presence of AA (0, 42.5, and 85 mg/test meal) from a casein/whey-based drink fortified with ferrous sulfate was assessed in a series of randomized crossover studies both in iron-replete (IR) Indian schoolchildren and in children with iron deficiency anemia (IDA) (6-11 y; n = 14-16/group) by using stable isotopes.

RESULTS

In the absence of calcium and AA, iron absorption from the casein/whey-based drink was 20% lower in IR children than in children with IDA. The addition of calcium reduced mean iron absorption by 18-27%, with the effect being stronger for high added calcium (P < 0.01). AA at a 2:1 or 4:1 molar ratio enhanced iron absorption by a factor of 2-4 and greatly overcompensated for the inhibitory effect of calcium on iron absorption in a dose-dependent manner (P < 0.001). The dose-response effect tended to be stronger (P < 0.1) in the IDA group, and iron status was of far less influence on iron absorption than the enhancing effect of AA.

CONCLUSION

When adding AA to iron-fortified milk products, care should be taken not to provide absorbable iron in excess of needs.

Influence of phytase, EDTA, and polyphenols on zinc absorption in adults from porridges fortified with zinc sulfate or zinc oxide

Fortification of cereal staples with zinc is recommended to combat zinc deficiency. To optimize zinc absorption, strategies are needed to overcome the inhibitory effect of phytic acid (PA) and perhaps polyphenols. Five zinc absorption studies were conducted in young adults consuming maize or sorghum porridges fortified with 2 mg zinc as zinc sulfate (ZnSO4) or zinc oxide (ZnO) and containing combinations of PA or polyphenols as potential inhibitors and EDTA and phytase as potential enhancers. Fractional absorption of zinc (FAZ) was measured by using the double isotopic tracer ratio method. Adding phytase to the maize porridge immediately before consumption or using phytase for dephytinization during meal preparation both increased FAZ by >80% (both P < 0.001). Adding Na2EDTA at an EDTA:zinc molar ratio of 1:1 increased FAZ from maize porridge fortified with ZnSO4 by 30% (P = 0.01) but had no influence at higher EDTA ratios or on absorption from ZnO. FAZ was slightly higher from ZnSO4 than from ZnO (P = 0.02). Sorghum polyphenols had no effect on FAZ from dephytinized sorghum porridges but decreased FAZ by 20% from PA-rich sorghum porridges (P < 0.02). The combined inhibitory effect of polyphenols and PA was overcome by EDTA. In conclusion, ZnSO4 was better absorbed than ZnO, phytase used to degrade PA during digestion or during food preparation substantially increased zinc absorption from zinc-fortified cereals, EDTA at a 1:1 molar ratio modestly enhanced zinc absorption from ZnSO4-fortified cereals but not ZnO-fortified cereals, and sorghum polyphenols inhibited zinc absorption in the presence, but not absence, of PA. This trial was registered at clinicaltrials.gov as NCT01210794.

Bioavailability of iron, zinc, folic acid, and vitamin A from fortified maize

Several strategies appear suitable to improve iron and zinc bioavailability from fortified maize, and fortification per se will increase the intake of bioavailable iron and zinc. Corn masa flour or whole maize should be fortified with sodium iron ethylenediaminetetraacetate (NaFeEDTA), ferrous fumarate, or ferrous sulfate, and degermed corn flour should be fortified with ferrous sulfate or ferrous fumarate. The choice of zinc fortificant appears to have a limited impact on zinc bioavailability. Phytic acid is a major inhibitor of both iron and zinc absorption. Degermination at the mill will reduce phytic acid content, and degermed maize appears to be a suitable vehicle for iron and zinc fortification. Enzymatic phytate degradation may be a suitable home-based technique to enhance the bioavailability of iron and zinc from fortified maize. Bioavailability experiments with low phytic acid-containing maize varieties have suggested an improved zinc bioavailability compared to wild-type counterparts. The bioavailability of folic acid from maize porridge was reported to be slightly higher than from baked wheat bread. The bioavailability of vitamin A provided as encapsulated retinyl esters is generally high and is typically not strongly influenced by the food matrix, but has not been fully investigated in maize.

Probiotics Lactobacillus reuteri DSM 17938 and Lactobacillus casei CRL 431 modestly increase growth, but not iron and zinc status, among Indonesian children aged 1-6 years

Probiotics and milk calcium may increase resistance to intestinal infection, but their effect on growth and iron and zinc status of Indonesian children is uncertain. We investigated the hypotheses that cow milk with added probiotics would improve growth and iron and zinc status of Indonesian children, whereas milk calcium alone would improve growth but reduce iron and zinc status. A 6-mo randomized trial was conducted in low-socioeconomic urban communities of Jakarta. Healthy children (n = 494) were randomly assigned to receive low-lactose milk with a low calcium content of ∼50 mg/d (LC; n = 124), a regular calcium content of ∼440 mg/d (RC group; n = 126), regular calcium with 5 × 10(8) CFU/d Lactobacillus casei CRL 431 (casei; n = 120), or regular calcium with 5 × 10(8) CFU/d Lactobacillus reuteri DSM 17938 (reuteri; n = 124). Growth, anemia, and iron and zinc status were assessed before and after the intervention. Compared with the RC group, the reuteri group had significantly greater weight gain [0.22 (95% CI: 0.02, 0.42) kg], weight-for-age Z-score (WAZ) changes [0.09 (95% CI: 0.01, 0.17)], and monthly weight [0.03 (95% CI: 0.002, 0.05) kg/mo] and height [0.03 (95% CI: 0.01, 0.05) cm/mo] velocities. Casei significantly increased monthly weight velocity [0.03 (95% CI: 0.001, 0.05) kg/mo], but not height. However, the changes in underweight, stunting, anemia prevalence, and iron and zinc status were similar between groups. In conclusion, L. reuteri DSM 17938 modestly improved growth by increasing weight gain, WAZ changes, and weight and height velocity, whereas L. casei CRL 431 modestly improved weight velocity. Independent from probiotics supplementation, regular milk calcium did not affect growth or iron and zinc status.

EDTA disodium zinc has superior bioavailability compared to common inorganic or chelated zinc compounds in rats fed a high phytic acid diet

Different zinc (Zn) compounds have unique properties that may influence the amount of Zn absorbed particularly in the presence of phytic acid (PA), a common food component that binds Zn and decreases its bioavailability. In this study, 30-day-old male rats (n=12/diet group) were fed diets supplemented with PA (0.8%) and low levels (8mg Zn/kg diet) of inorganic (Zn oxide, Zn sulphate) or chelated (Zn gluconate, Zn acetate, Zn citrate, EDTA disodium Zn, Zn orotate) Zn compounds for 5 weeks. Two control groups were fed diets supplemented with low or normal (30mg Zn/kg diet) Zn (as Zn oxide) without added PA. Control rats fed the low Zn oxide diet showed depressed Zn status. Addition of PA to this diet exacerbated the Zn deficiency in rats. Growth (body weight gain and femur length) and Zn concentrations in plasma and tissues were similar in rats fed Zn oxide, Zn sulphate, Zn gluconate, Zn acetate, Zn citrate or Zn orotate. Rats fed EDTA disodium Zn showed enhanced growth compared to rats fed Zn oxide or Zn gluconate and had higher Zn concentrations in plasma and femur compared to rats fed all other Zn compounds. Only the haematological profile of rats fed EDTA disodium Zn did not differ from control rats fed normal Zn. These data indicate that in rats fed a high PA diet, bioavailability of commonly used inorganic or chelated Zn compounds does not differ appreciably, but Zn supplied as an EDTA disodium salt has superior bioavailability.

Effect of multiple fortification on the bioavailability of minerals in wheat meal bread

Bioavailability of calcium, iron and zinc as calcium carbonate (CaCO3), ferrous sulfate (FeSO4) and zinc sulphate (ZnSO4) @ 1,000, 40 and 20 mg kg(-1) respectively from fortified bread of 72% extraction straight grade flour was assessed. Fortified bread diets were fed to 64 female Sprague-Dawley Albino rats for a period of 28 days. The retention of Ca, Fe and Zn was measured in plasma, femur and liver tissues of rats. The results showed that the feed intake and live body weight of the experimental animals increased significantly with the time period. The Ca levels in plasma and liver did not change significantly while in femur, Ca retention changed significantly with changing type of the fortificants. Similarly, the results for percent apparent absorption (AA) of Ca also remained unchanged (P < 0.05). The Fe and Zn levels were significantly higher in the plasma, liver and femur of rats fed Fe and Zn fortified bread. Interaction of Ca, Fe and Zn resulted in their decreased bioavailability. However Ca, Fe and Zn absorption was higher in the rats fed triple fortified diet compared with those fed unfortified bread diet. This negative interaction did not appear to be great enough to discourage multiple fortification of flour to address minerals malnutrition in the vulnerable groups.

Zinc fortification of cereal flours: current recommendations and research needs

BACKGROUND

Zinc fortification is recommended as an appropriate strategy to enhance population zinc status, but guidelines are needed on the appropriate types and levels of zinc fortification of cereal flours for mass fortification programs.

OBJECTIVE

To review available information on the scientific rationale, efficacy, and effectiveness of zinc fortification programs, and to develop guidelines on appropriate levels of fortification of cereal flours, based on simulations of the amount of zinc absorbed under different dietary conditions and information on possible adverse effects.

METHODS

Systematic review of scientific literature and application of an existing prediction equation to estimate zinc absorption.

RESULTS

Previously completed research demonstrates that zinc intake and absorption are increased when zinc-fortified foods are consumed, but little information is, as yet, available on the biologic impact of large-scale fortification programs. Studies suggest that there are no disadvantages of the recommended ranges of zinc fortification with regard to the sensory properties of zinc-fortified foods, and most research indicates that there are no adverse effects of zinc fortification on the utilization of other minerals.

CONCLUSIONS

Zinc fortification of cereal flour is a safe and appropriate strategy for enhancing the zinc status of population subgroups who consume adequate amounts of fortified cereal flour, although additional information is needed to confirm the efficacy and effectiveness of large-scale zinc fortification programs to control zinc deficiency. The appropriate level of fortification depends on the population subgroup, their usual amount of flour intake, the degree of milling and fermentation that is practiced, and the usual intakes of zinc and phytate from other food sources. Fortification recommendations are presented for different dietary scenarios.

Multiple micronutrients including iron are not more effective than iron alone for improving hemoglobin and iron status of Malian school children

Iron deficiency and anemia remain among the most important global public health problems facing school children. Helminth infections often peak at school age and aggravate nutritional risks. We conducted a 12-wk randomized controlled trial in 406 Malian anemic schoolchildren infected with Schistosoma hematobium to examine the effects of 2 doses of praziquantel (P) (40 mg/kg body weight), P + 60 mg/d iron (Fe), and/or a multiple micronutrient supplement (MM) that included 18 mg/d Fe. Supplements were administered to the children each school day (5 d/wk) throughout the study. Changes in hemoglobin (Hb), serum ferritin (SF), and serum transferrin receptors (s-TfR) were followed. We also examined interactions between Fe and MM supplements on Hb and SF concentrations and malaria incidence. The effects of Fe on Hb and SF concentrations were greater than the effects of P alone and MM with or without added Fe at 6 and 12 wk (P < 0.001). In all groups, s-TfR decreased at 6 and 12 wk compared with baseline. The decrease was most pronounced in the P + Fe group compared with the other 3 groups at wk 6 (P = 0.05). Fe and MM interacted negatively at wk 6 and 12 to affect Hb (beta = -0.43, 95% CI = -0.77, -0.09; P = 0.01 and beta = -0.47, 95% CI = -0.83, -0.11; P = 0.01, respectively) and SF (beta = -0.42, 95% CI = -25.60, 12.31; P < 0.001, and beta = -0.37, 95% CI = -0.63, -0.12; P = 0.004, respectively). Malaria incidence was higher in the groups treated with added Fe (relative risk: 1.66; 95% CI: 0.75, 3.67). In this context, MM with added iron were not more effective than Fe without MM. Fe supplementation of schoolchildren with 60 mg/d for anemia control should be considered carefully.

Impact of Zinc Fortification on Zinc Nutrition

Food fortification is increasingly recognized as an effective approach to improve a population's micronutrient status. The present report provides a critical review of the scientific evidence currently available on the impact of zinc fortification on zinc nutrition.

The available studies clearly show that zinc fortification can increase dietary zinc intake and total daily zinc absorption. Most absorption studies also indicate that adding zinc to food does not adversely affect the absorption of other minerals, such as iron. Despite the positive effect of zinc fortification on total zinc absorption, only a few studies have found positive impacts of zinc fortification on serum zinc concentrations or functional indicators of zinc status. The reasons for these inconsistent results are uncertain but may relate to the choice of food vehicles, the age group and zinc status of the study populations, or particular aspects of the study design. Thus, additional research is needed to determine the impact of zinc fortification, with or without other micronutrients, in populations at risk for zinc deficiency.

Because of the benefits of increasing intake in populations at high risk for zinc deficiency, the documented increase in total zinc absorption that occurs following zinc fortification, the absence of any adverse effects, and the relatively low cost of adding zinc, public health planners should consider including zinc in mass and targeted fortification programs in such populations. Because of the limited available information on program impact, it will be important to evaluate the outcomes of such programs.

Demonstrating zinc and iron bioavailability from intrinsically labeled microencapsulated ferrous fumarate and zinc gluconate Sprinkles in young children

Nutrient-nutrient interactions are an important consideration for any multiple-micronutrient formulation, including Sprinkles, a home-fortification strategy to control anemia. The objectives of this randomized controlled trial were as follows: 1) to compare the absorption of zinc at 2 doses given as Sprinkles; and 2) to examine the effect of zinc and ascorbic acid (AA) on iron absorption from Sprinkles. Seventy-five children aged 12-24 mo were randomly assigned to the following groups: 1) 5 mg of labeled zinc (67Zn) with 50 mg AA (LoZn group); b) 10 mg of labeled zinc (67Zn) with 50 mg AA (HiZn group); or 3) 5 mg zinc with no AA (control). All groups contained 30 mg of labeled iron (57Fe). Intravenous infusions labeled with 70Zn (LoZn and HiZn groups) and 58Fe (control) were administered. Blood was drawn at baseline, 48 h and 14 d later. The percentage of zinc absorbed did not differ between LoZn (geometric mean = 6.4%; min-max: 1.7-14.6) and HiZn (geometric mean = 7.5%; min-max: 3.3-18.0) groups. However, total zinc absorbed was significantly different between the LoZn (geometric mean = 0.31 mg; min-max: 0.08-0.73) and HiZn (geometric mean = 0.82 mg; min-max: 0.33-1.82) groups (P = 0.0004). Geometric mean percentage iron absorption values did not differ between the LoZn (5.9%; min-max: 0.8-21) and HiZn (4.4%; min-max: 0.6-12.3) groups and between the LoZn and control groups (5.0%; min-max: 1.4-24). We conclude that zinc in the form of Sprinkles has a low bioavailability, yet provides adequate amounts of absorbed zinc in young children, and that there is no effect of zinc or AA on iron absorption from the given formulations of Sprinkles.

The addition of milk or yogurt to a plant-based diet increases zinc bioavailability but does not affect iron bioavailability in women

The addition of milk and milk-based products to the diets of individuals subsisting on plant-based diets was reported to have positive effects on nutritional status and functional outcomes such as growth, morbidity, and cognition. We examined the effect of the addition of milk or yogurt on the bioavailability of zinc and iron from a plant-based rural diet. The subjects were 48 Mexican women (30.9 +/- 5.7 y) who habitually consumed a plant-based diet. The women were assigned to 1 of 3 groups: 1) the typical rural Mexican diet, 2) that diet with milk added, or 3) that diet with yogurt for 13 d. Zinc absorption was measured after extrinsically labeling meals with (67)Zn and an i.v. dose of (70)Zn; iron absorption was measured by extrinsically labeling meals with (58)Fe and a reference oral dose of (57)Fe. Including milk and yogurt in the diet increased zinc absorption by 50 and 68%, respectively (P < 0.05). The 3 groups did not differ in the percentage iron absorption. The total amount of zinc absorbed was increased (P < 0.05) by 70% when milk was added to the meal and 78% when yogurt was added. The total amount of iron absorbed did not differ among the groups. The addition of milk and yogurt to a plant-based diet high in phytate increases zinc bioavailability without affecting iron bioavailability.