Nutrient and nontraditional food intakes by Zambian children in a controlled feeding trial

Inadequate Niacin Intake Disrupts Growth and Retinol Homeostasis Resulting in Higher Liver and Lower Serum Retinol Concentrations in Male Rats

BACKGROUND

Niacin-derived nicotinamide adenine dinucleotide is an essential cofactor for many dehydrogenase enzymes involved in vitamin A (VA) metabolism. Several countries with high prevalence of VA deficiency rely on maize, a poor source of available niacin, as a dietary staple.

OBJECTIVES

This study evaluated the interaction of dietary niacin on VA homeostasis using male Sprague-Dawley rats, aged 21 d (baseline body weight 88.3 ± 6.6 g).

METHODS

After 1 wk of acclimation, baseline samples were collected (n = 4). Remaining rats (n = 54) were split into 9 groups to receive low tryptophan, VA-deficient feed with 3 different amounts of niacin (0, 15, or 30 mg/kg) and 3 different oral VA doses (50, 350, or 3500 nmol/d) in a 3 × 3 design. After 4 wk, the study was terminated. Serum, livers, and small intestine were analyzed for retinoids using high-performance liquid chromatography. Niacin and metabolites were evaluated with nuclear magnetic resonance. Plasma pyridoxal-P (PLP) was measured with high-performance liquid chromatography.

RESULTS

Niacin intake correlated with serum retinol concentrations (r = 0.853, P < 0.001). For rats receiving the highest VA dose, liver retinol concentrations were lower in the 30-mg/kg niacin group (5.39 ± 0.27 μmol/g) than those in the 0-mg/kg and 15-mg/kg groups (9.18 ± 0.62 and 8.75 ± 0.07 μmol/g, respectively; P ≤ 0.05 for both). This phenomenon also occurred in the lower VA doses (P ≤ 0.05 for all). Growth and tissue weight at endline were associated with niacin intake (P ≤ 0.001 for all). Plasma PLP correlated with estimated niacin intake (r = 0.814, P < 0.001).

CONCLUSIONS

Optimal niacin intake is associated with lower liver VA and higher serum retinol and plasma PLP concentrations. The extent to which vitamin B intake affects VA homeostasis requires further investigation to determine if the effects are maintained in humans.

Comparison of Total Body Vitamin A Stores Using Individual versus Population 13C-Natural Abundance of Serum Retinol in Preschool Children and Women Residing in 6 Diverse African Countries

BACKGROUND

Stable isotope techniques using 13C to assess vitamin A (VA) dietary sources, absorption, and total body VA stores (TBSs) require determination of baseline 13C abundance. 13C-natural abundance is approximately 1.1% total carbon, but varies with foods consumed, supplements taken, and food fortification with synthetic retinyl palmitate.

OBJECTIVES

We determined 13C variation from purified serum retinol and the resulting impact on TBSs using pooled data from preschool children in Burkina Faso, Cameroon, Ethiopia, South Africa, Tanzania, and Zambia and Zambian women.

METHODS

Seven studies included children (n = 639; 56 ± 25 mo; 48% female) and one in women (n = 138; 29 ± 8.5 y). Serum retinol 13C-natural abundance was determined using GC-C-IRMS. TBSs were available in 7 studies that employed retinol isotope dilution (RID). Serum CRP and α1-acid-glycoprotein (AGP) were available from 6 studies in children. Multivariate mixed models assessed the impact of covariates on retinol 13C. Spearman correlations and Bland-Altman analysis compared serum and milk retinol 13C and evaluated the impact of using study- or global-retinol 13C estimates on calculated TBSs.

RESULTS

13C-natural abundance (%, median [Q1, Q3]) differed among countries (low: Zambia, 1.0744 [1.0736, 1.0753]; high: South Africa, 1.0773 [1.0769, 1.0779]) and was associated with TBSs, CRP, and AGP in children and with TBSs in women. 13C-enrichment from serum and milk retinol were correlated (r = 0.52; P = 0.0001). RID in children and women using study and global estimates had low mean bias (range, -3.7% to 2.2%), but larger 95% limits of agreement (range, -23% to 37%).

CONCLUSIONS

13C-natural abundance is different among human cohorts in Africa. Collecting this information in subgroups is recommended for surveys using RID. When TBSs are needed on individuals in clinical applications, baseline 13C measures are important and should be measured in all enrolled subjects.

Evolution of energy and nutrient supply in Zambia (1961–2013) in the context of policy, political, social, economic, and climatic changes

An adequate supply of energy, micronutrients and macronutrients is essential to achieve food and nutrition security to prevent malnutrition. Socio-economic, political, and climatic events, however, can affect the supply of food and nutrients. We assessed country-level supply trends of food and nutrients and their sources within the context of policy changes and political, socio-economic and climatic events from 1961 to 2013 in Zambia. Due to the lack of national food consumption data, food supply data from the FAO food balance sheets, matched to food composition tables, were used to estimate the energy, macronutrient and micronutrient content of 264 food items available to Zambia. We calculated historical nutrient supplies based on demographic characteristics and population-level dietary requirements. Results showed that Zambia was nutrition insecure from 1961 to 2013 for key micronutrients vitamin A, folate, riboflavin, vitamin B12, calcium, zinc, iron, and energy-deficient from the late-1980s. The diet has not substantially changed over time, with maize being the dominant food source. However, refined energy-dense food has steadily increased in the diet coupled with a reduction in fibre. These nutrient supply and dietary pattern trends coincide with specific socio-economic, policy, political, and climatic events from the 1970s to the early-mid 2000s, such as population growth, maize subsidy and crop diversification policies, regime change and drought. This study shows how policy, political and climatic events have been central features shaping nutrient supplies and the consequences for nutrition security. The study provides a context to inform future food policies to improve food and nutrition security.

Global Trends in the Availability of Dietary Data in Low and Middle-Income Countries

Individual-level quantitative dietary data can provide suitably disaggregated information to identify the needs of all population sub-groups, which can in turn inform agricultural, nutrition, food safety, and environmental policies and programs. The purpose of this discussion paper is to provide an overview of dietary surveys conducted in low- and middle-income countries (LMICs) from 1980 to 2019, analyzing their key characteristics to understand the trends in dietary data collection across time. The present study analyzes the information gathered by the Food and Agriculture Organization of the United Nations/World Health Organization Global Individual Food consumption data Tool (FAO/WHO GIFT). FAO/WHO GIFT is a growing repository of individual-level dietary data and contains information about dietary surveys from around the world, collected through published survey results, literature reviews, and direct contact with data owners. The analysis indicates an important increase in the number of dietary surveys conducted in LMICs in the past four decades and a notable increase in the number of national dietary surveys. It is hoped that this trend continues, together with associated efforts to validate and standardize the dietary methods used. The regular implementation of dietary surveys in LMICs is key to support evidence-based policies for improved nutrition.

Findings in 3 clinical trials challenge the accuracy of the Institute of Medicine's estimated average requirements for vitamin A in children and women

BACKGROUND

Vitamin A (VA) estimated average requirements (EARs) for women and children are extrapolated from rats and adult males. The retinol isotope dilution (RID) test can sensitively characterize VA status and intake requirements.

OBJECTIVES

These studies evaluated current EARs for children 4-8 y and women 19-30 y old.

METHODS

Zambian children (n = 133, ages 5-7 y), US women (n = 51, ages 19-27 y), and Indonesian women (n = 29, ages 19-30 y) were provided diets or supplements containing 30%-155% of VA EARs for 42-90 d. RID was performed before and after the intervention to quantify changes in total body VA stores (TBSs) and total liver VA reserves (TLRs). Linear regression was performed between VA intake and change in TBSs or TLRs.

RESULTS

Baseline mean ± SD TLRs were hypervitaminotic in Zambian children (1.13 ± 0.41 μmol VA/g liver), optimal in US women (0.46 ± 0.32 μmol/g VA/g liver), and deficient to marginal in Indonesian women (0.10 ± 0.08 μmol VA/g liver). VA intakes, resulting in no change in TBSs or TLRs, were 185 (95% CI: 18, 288) or 257 (95% CI: 124, 411) and 285 or 330 (CIs undefined) μg retinol activity equivalents (RAE)/d in the Zambian and US trials, respectively, but inconclusive in Indonesian women. The regression was not significant in either group of women.

CONCLUSIONS

Point estimates of VA intakes to maintain stores were below the current EARs of 275 (children) and 500 (women) μg RAE/d despite the TLRs being higher than the EARs were formulated to maintain (i.e., 0.07 μmol VA/g liver). Interventions based on these EARs may need to be scaled back. Lack of change in VA stores in women taking lower doses may result from physiological adaptation resulting in lower VA utilization. Longer, larger, and controlled studies are needed to accurately define EARs for VA.These trials were registered at Clinicaltrials.gov as NCT04123210 and NCT01814891.

Overlapping Vitamin A Interventions with Provitamin A Carotenoids and Preformed Vitamin A Cause Excessive Liver Retinol Stores in Male Mongolian Gerbils

BACKGROUND

Vitamin A (VA) deficiency is a public health problem in some countries. Fortification, supplementation, and increased provitamin A consumption through biofortification are efficacious, but monitoring is needed due to risk of excessive VA intake when interventions overlap.

OBJECTIVES

Two studies in 28-36-d-old male Mongolian gerbils simulated exposure to multiple VA interventions to determine the effects of provitamin A carotenoid consumption from biofortified maize and carrots and preformed VA fortificant on status.

METHODS

Study 1 was a 2 × 2 × 2 factorial design (n = 85) with high-β-carotene maize, orange carrots, and VA fortification at 50% estimated gerbil needs, compared with white maize and white carrot controls. Study 2 was a 2 × 3 factorial design (n = 66) evaluating orange carrot and VA consumption through fortification at 100% and 200% estimated needs. Both studies utilized 2-wk VA depletion, baseline evaluation, 9-wk treatments, and liver VA stores by HPLC. Intestinal scavenger receptor class B member 1 (Scarb1), β-carotene 15,15'-dioxygenase (Bco1), β-carotene 9',10'-oxygenase (Bco2), intestine-specific homeobox (Isx), and cytochrome P450 26A1 isoform α1 (Cyp26a1) expression was analyzed by qRT-PCR in study 2.

RESULTS

In study 1, liver VA concentrations were significantly higher in orange carrot (0.69 ± 0.12 μmol/g) and orange maize groups (0.52 ± 0.21 μmol/g) compared with baseline (0.23 ± 0.069 μmol/g) and controls. Liver VA concentrations from VA fortificant alone (0.11 ± 0.053 μmol/g) did not differ from negative control. In study 2, orange carrot significantly enhanced liver VA concentrations (0.85 ± 0.24 μmol/g) relative to baseline (0.43 ± 0.14 μmol/g), but VA fortificant alone (0.42 ± 0.21 μmol/g) did not. Intestinal Scarb1 and Bco1 were negatively correlated with increasing liver VA concentrations (P < 0.01, r2 = 0.25-0.27). Serum retinol concentrations did not differ.

CONCLUSIONS

Biofortified carrots and maize without fortification prevented VA deficiency in gerbils. During adequate provitamin A dietary intake, preformed VA intake resulted in excessive liver stores in gerbils, despite downregulation of carotenoid absorption and cleavage gene expression.

Assessment of Dietary Diversity of Mothers and Children of 6–24 Months from Eastern and Southern Provinces of Zambia

In-depth information on dietary diversity and food consumption patterns in Zambian households is still scarce. This study, therefore, probed dietary intakes of mothers and their children living in households of two Zambian districts, Chipata and Monze, located in the eastern and southern provinces of Zambia, respectively. After assessing their diet, Dietary Diversity Scores (DDSs) were calculated and classified into low and high categories, while correlations were used to test determinants of DDS. The assessment revealed that the consumption of cereal-based products ranked highest in frequency. Specifically, the consumption of maize-based foods was highest in Chipata (55.43%) and then in Monze (43.56%) households. There was an observed low preference for mixed dishes that were not either maize or groundnut porridges. We also found positive and negative correlations of DDS with the educational level of household heads and age of mothers, respectively. We, therefore, suggest that increased nutrition education may improve dietary preferences, so also further investigation into other factors hindering low choices for mixed recipes will be useful in increasing overall diet quality.

Restricting vitamin A intake increases bone formation in Zambian children with high liver stores of vitamin

This analysis was performed in Zambian children who had a high prevalence of hypervitaminosis A, defined as > 1.0 μmol retinol/g liver. Bone parameters included markers of bone formation (P1NP), bone resorption (CTX), parathyroid hormone, calcium, vitamin A, and vitamin D. Low dietary vitamin A intake increased P1NP.

PURPOSE

Vitamin A (VA) interacts with bone health, but mechanisms require clarification. In countries where multiple interventions exist to eradicate VA deficiency, some groups are consuming excessive VA. Bone metabolism and inflammatory parameters were measured in Zambian children who had high prevalence of hypervitaminosis A determined by ¹³C-retinol isotope dilution.

METHODS

Children (n = 143), 5 to 7 years, were recruited into a placebo-controlled biofortified orange maize feeding study for 90 days. Bone turnover (P1NP and CTX) and inflammatory (C-reactive protein (CRP) and alpha-1-acid glycoprotein) biomarkers were measured in fasting blood samples before and/or after intervention with the following: (1) VA at the recommended dietary allowance (400 μg retinol activity equivalents/day (as retinyl palmitate)), (2) maize enhanced with the provitamin A carotenoid β-carotene (2.86 mg/day), or (3) a placebo. Parathyroid hormone, calcium, and 25(OH)-vitamin D were measured at end line.

RESULTS

Bone formation, as measured by P1NP, increased (P < 0.0001) in the placebo group who consumed low preformed VA during the intervention. Bone resorption, measured by CTX, was not affected. P1NP and CTX were negatively associated with inflammation, most strongly with CRP. Serum calcium did not differ among groups and was low (7.29 ± 0.87 μg/dL). Serum 25(OH) D did not differ among groups (54.5 ± 15 nmol/L), with 91% < 75 nmol/L and 38% < 50 nmol/L.

CONCLUSIONS

Reduction of dietary preformed VA in Zambian children for 4 months improved bone formation. Chronic consumption of preformed VA caused hypervitaminosis A and may impair bone formation. In children, this could be associated with failure to accrue optimal peak bone mass.

TRIAL REGISTRATION

The NIH Clinical Trial registry number is NCT01814891; https://clinicaltrials.gov/ct2/show/NCT01814891 .

Community mobilization during biofortified orange maize feeding trials in Zambia

In some societies, studies involving blood draws, oral vaccinations, or supplementation are surrounded by myths and disbeliefs. If not clarified, they may affect study implementation and negatively impact the outcome of well-intended studies from inadequate participation. Through participatory action research, this paper suggests how future trials could be enhanced with reference to community mobilization, drawing from the experience of two interventions in Zambian children with nutritionally enhanced, biofortified orange maize conducted by the National Food and Nutrition Commission and Tropical Diseases Research Center (Zambia), and University of Wisconsin-Madison (USA). The preparatory phase included site visits, signing of a Memorandum of Understanding, equipment inventory, hiring staff, and community meetings. Prior results were shared before the second intervention. After Institutional Review Boards' approval of procedures, written informed consent was obtained from caregivers. There was overwhelming community participation attributed to the demystification that the project was run by satanists prior to and during the study. Participation led to excellent compliance with 92.8 and 96.4% of subjects completing the final blood draw in 2010 and 2012, respectively. The results of the trials were successfully shared with the district officials and communities from where the study participants were drawn. The positive response by partners and communities, including information sharing, suggests that community mobilization, with the use of varied methods, is effective for full participation of the target groups in feeding trials and would be the case in similar trials if effectively carried out. Community participation in research studies may result in long-term adoption of biofortified foods.

Dietary Intake Patterns among Lactating and Non-Lactating Women of Reproductive Age in Rural Zambia

Insufficient dietary intake, micronutrient deficiencies, and infection may result in malnutrition. In Zambia, an estimated 14% of women are vitamin A-deficient, ~50% are anemic, 10% are underweight, and 23% are overweight/obese. A cross-sectional survey determined food and nutrient intakes of randomly selected Zambian women (n = 530) of reproductive age (15–49 years). Dietary intake data were collected using interactive multiple-pass 24-h recalls. Carbohydrate, fat, protein, and selected micronutrient intakes were estimated. Prevalence of adequate intakes were determined using the estimated average requirement (EAR) cut-point method and comparisons between lactating and non-lactating women were made by two-sample t-tests. The response rate was 98.7%. Overweight/obesity occurred in 20.7% (95% confidence interval (CI: 17.2, 24.5)). Almost all micronutrient intakes were inadequate, with values between 22.3% and 99.9%. Mean iron intake was >EAR, and 8.2% of women tested (12/146, 95% CI: 4.1, 13.0) were anemic (hemoglobin <115 g/L). Calcium intake was higher in lactating than non-lactating women (p = 0.004), but all intakes need improvement. Vitamin intakes in rural Zambian women are inadequate, suggesting a need for health promotion messages to encourage intake of locally available micronutrient-dense foods as well as supplementation, fortification, and biofortification initiatives. Nutritional support is important because maternal nutrition directly impacts child health.

β-Cryptoxanthin-Biofortified Hen Eggs Enhance Vitamin A Status When Fed to Male Mongolian Gerbils

Background

Consumption of provitamin A carotenoid biofortified crops, such as maize, supports vitamin A (VA) status in animals and humans. Laying hens that consume β-cryptoxanthin-biofortified maize deposit β-cryptoxanthin into egg yolk.

Objective

We investigated whether β-cryptoxanthin-biofortified egg consumption would affect VA status of male Mongolian gerbils (Meriones unguiculatus) compared with white-yolked eggs.

Methods

β-Cryptoxanthin-biofortified egg yolk, produced in hens fed biofortified orange maize or tangerine-fortified maize feeds, was freeze-dried and fed to gerbils. White-yolked eggs were produced by feeding white maize to hens. Gerbils (n = 57) were fed VA-deficient feed for 28 d. After baseline (n = 7), treatments (n = 10/group) included oil control (VA-); 16.7% orange maize-biofortified, tangerine-fortified, or white-yolk egg feeds; or retinyl acetate as positive control (VA+) matched to daily preformed retinol intake from the eggs for 30 d. Preformed retinol did not differ between the egg yolks. Gerbil liver retinol, lipid, fatty acids, and cholesterol were determined.

Results

Liver retinol concentration (0.13 ± 0.03 µmol/g) and total hepatic VA (0.52 ± 0.12 µmol) were higher in gerbils fed orange maize-biofortified eggs than in all other groups. The VA- group was severely VA deficient (0.018 ±0.010 µmol/g; P < 0.05). Liver retinol was similar among VA+, tangerine-egg-, and white-egg-fed gerbils, but retinol reserves were higher in tangerine-egg-fed gerbils (0.35 ± 0.11 μmol) than in VA+ or VA- gerbils or at baseline (P < 0.05). Liver fat was 3.6 times (P < 0.0001) and cholesterol was 2.1 times (P < 0.004) higher in egg-fed groups that experienced hepatosteatosis. Liver fatty acid profiles reflected feed, but retinyl ester fatty acids did not.

Conclusions

The preformed retinol in the eggs enhanced gerbil VA status, and the β-cryptoxanthin-biofortified eggs from hens fed orange maize prevented deficiency. Biofortified maize can enhance VA status when consumed directly or through products from livestock fed orange maize.

Suboptimal Vitamin B Intakes of Zambian Preschool Children: Evaluation of 24-Hour Dietary Recalls

Background:

Hidden hunger affects individuals who chronically consume an inadequate intake of at least 1 micronutrient and is associated with low dietary diversity. Little data are available on dietary intake or status assessment of B vitamins among preschool children in Zambia.

Objectives:

The aim of this study was to assess 24-hour dietary recall records obtained from Zambian children aged 3 to 7 years for B vitamin intake in relation to adequacy and change over time in the same community.

Methods:

Twenty-four-hour dietary recalls were collected from 2 studies that were 2 years apart in the same district of Zambia. Data were retrospectively analyzed for B vitamin intake, that is, biotin, vitamin B12, folate, niacin, pantothenic acid, vitamin B6, riboflavin, and thiamin. The estimated average requirement (EAR) cut point method was used to assess inadequacy prevalence for EARs established by the Institute of Medicine in the United States.

Results:

For all B vitamins, mean values were below the EARs established for children 4 to 8 years old. Relative to the EAR, children had the highest intakes of vitamin B6 with inadequacies of 77.9% and 60.1% in 2010 and 2012, respectively. The highest prevalence of inadequate intake was associated with folate, where ≥95% of the children had intakes below the EAR in both studies.

Conclusions:

All median vitamin B intakes were inadequate among these young children in rural Zambia. Future researchers and policy makers may need to consider B vitamin status in resource-poor areas of the country.

Retention of Carotenoids in Biofortified Maize Flour and β-Cryptoxanthin-Enhanced Eggs after Household Cooking

Biofortification of crops to enhance provitamin A carotenoids is a strategy to increase the intake where vitamin A deficiency presents a widespread problem. Heat, light, and oxygen cause isomerization and oxidation of carotenoids, reducing provitamin A activity. Understanding provitamin A retention is important for assessing efficacy of biofortified foods. Retention of carotenoids in high-xanthophyll and high-β-carotene maize was assessed after a long-term storage at three temperatures. Carotenoid retention in high-β-cryptoxanthin maize was determined in muffins, non-nixtamalized tortillas, porridge, and fried puffs made from whole-grain and sifted flour. Retention in eggs from hens fed high-β-cryptoxanthin maize was assessed after frying, scrambling, boiling, and microwaving. Loss during storage in maize was accelerated with increasing temperature and affected by genotype. Boiling whole-grain maize into porridge resulted in the highest retention of all cooking and sifting methods (112%). Deep-fried maize and scrambled eggs had the lowest carotenoid retention rates of 67-78 and 84-86%, respectively.

Acceptance and adoption of biofortified crops in low- and middle-income countries: a systematic review

CONTEXT

Biofortification of staple crops is a promising strategy for increasing the nutrient density of diets in order to improve human health. The willingness of consumers and producers to accept new crop varieties will determine whether biofortification can be successfully implemented. This review assessed sensory acceptance and adoption of biofortified crops and the determining factors for acceptance and adoption among consumers and producers in low- and middle-income countries. PubMed, Scopus, and Web of Science were searched for published reports. Unpublished studies were identified using an internet search. From a total of 1669 records found, 72 primary human research studies published in English or Spanish met the criteria for inclusion. : Data were extracted from each identified study using a standardized form. Sensory acceptability (n = 40) was the most common topic of the studies, followed by determinants of acceptance (n = 25) and adoption (n = 21). Of crops included in the studies, sweet potato and maize were the most studied, whereas rice and pearl-millet were the least investigated. Overall, sensory acceptance was good, and availability and information on health benefits of the crops were the most important determinants of acceptance and adoption. : Changes to the sensory qualities of a crop, including changes in color, did not act as an obstacle to acceptance of biofortified crops. Future studies should look at acceptance of biofortified crops after they have been disseminated and introduced on a wide-scale.

The research and implementation continuum of biofortified sweet potato and maize in Africa

The enhancement of sweet potato and maize with provitamin A carotenoids has been part of HarvestPlus's research continuum since the formation of the biofortification project. This review includes case studies of biofortification strategies used for sweet potato in Uganda and orange maize in Zambia. The current status of the science and release of biofortified varieties was reviewed by three scientists who were part of the HarvestPlus program for more than a decade with input from a scientist who experienced orange maize dissemination in Zambia. High β-carotene varieties of sweet potato were introduced into South Africa and Mozambique, and efficacy and effectiveness studies, respectively, showed promise to improve vitamin A status, followed by dissemination efforts in Uganda. A randomized, controlled effectiveness trial tested extension models to promote sweet potato and assessed vitamin A intake among Ugandans. Orange maize breeding was initially a challenge, but considering that the carotenoid biosynthetic pathway was present in maize germplasm, breeders quickly bred higher amounts of provitamin A into the maize that was ultimately released in Zambia. Initial resistance occurred because orange maize was associated with yellow maize, which had negative connotations associated with food aid and animal feed, and consumers preferred white maize. Currently, both orange crops are available on the market.

The Nutritional Contribution of Foods and Beverages Provided by Government-Sponsored Day Care Centers in Guatemala

BACKGROUND

Meals served at government-run day care centers must be nutritionally adequate to ensure good health and proper development of preschool-aged children. They can provide a controlled opportunity to complement the daily diet of children in vulnerable populations.

OBJECTIVE

To determine the nutrient adequacy and leading food sources of nutrients provided by the diet served in government-sponsored day care centers.

METHODS

Estimated daily energy and nutrient intakes of a theoretical 40-day day care center menu were calculated, and the nutrient adequacy was assessed. Nutrient densities and critical nutrient densities of the menu were computed to identify nutrient inadequacies. Furthermore, main sources of nutrients were identified, and energy and nutrient distributions were examined by meal time.

RESULTS

The menu provides approximately 90% of daily energy requirement and more than 100% of Recommended Nutrient Intakes (RNIs), with the exception of vitamin D and calcium. Sugar was the first leading source of energy, whereas milk was the first leading contributor of vitamin D.

CONCLUSION

Within an environment of budgetary constraints, the Guatemalan government developed and advocated an exemplary menu offering for children in the vulnerable preschool period. We have demonstrated that, if prepared and served as planned, the items from the official, standard menu would supply most of the nutrients needed. High vitamin A intake related to the mandated national fortification program is a potential problem. From the analysis, it was found that vitamin D emerges as the most prominent candidate for a problem nutrient of deficient intake.

High provitamin A carotenoid serum concentrations, elevated retinyl esters, and saturated retinol-binding protein in Zambian preschool children are consistent with the presence of high liver vitamin A stores

BACKGROUND

Biomarkers of micronutrient status are needed to best define deficiencies and excesses of essential nutrients.

OBJECTIVE

We evaluated several supporting biomarkers of vitamin A status in Zambian children to determine whether any of the biomarkers were consistent with high liver retinol stores determined by using retinol isotope dilution (RID).

DESIGN

A randomized, placebo-controlled, biofortified maize efficacy trial was conducted in 140 rural Zambian children from 4 villages. A series of biomarkers were investigated to better define the vitamin A status of these children. In addition to the assessment of total-body retinol stores (TBSs) by using RID, tests included analyses of serum carotenoids, retinyl esters, and pyridoxal-5'-phosphate (PLP) by using high-pressure liquid chromatography, retinol-binding protein by using ELISA, and alanine aminotransferase (ALT) activity by using a colorimetric assay.

RESULTS

Children (n = 133) were analyzed quantitatively for TBSs by using RID. TBSs, retinyl esters, some carotenoids, and PLP differed by village site. Serum carotenoids were elevated above most nonintervened reference values for children. α-Carotene, β-carotene, and lutein values were >95th percentile from children in the US NHANES III, and 13% of children had hypercarotenemia (defined as total carotenoid concentration >3.7 μmol/L). Although only 2% of children had serum retinyl esters >10% of total retinol plus retinyl esters, 16% of children had >5% as esters, which was consistent with high liver retinol stores. Ratios of serum retinol to retinol-binding protein did not deviate from 1.0, which indicated full saturation. ALT activity was low, which was likely due to underlying vitamin B-6 deficiency, which was confirmed by very low serum PLP concentrations.

CONCLUSIONS

The finding of hypervitaminosis A in Zambian children was supported by high circulating concentrations of carotenoids and mildly elevated serum retinyl esters. ALT-activity assays may be compromised with co-existing vitamin B-6 deficiency. Nutrition education to improve intakes of whole grains and animal-source foods may enhance vitamin B-6 status in Zambians.

Biofortified orange maize is as efficacious as a vitamin A supplement in Zambian children even in the presence of high liver reserves of vitamin A: a community-based, randomized placebo-controlled trial

BACKGROUND

Biofortification is a strategy to relieve vitamin A (VA) deficiency. Biofortified maize contains enhanced provitamin A concentrations and has been bioefficacious in animal and small human studies.

OBJECTIVE

The study sought to determine changes in total body reserves (TBRs) of vitamin A with consumption of biofortified maize.

DESIGN

A randomized, placebo-controlled biofortified maize efficacy trial was conducted in 140 rural Zambian children. The paired (13)C-retinol isotope dilution test, a sensitive biomarker for VA status, was used to measure TBRs before and after a 90-d intervention. Treatments were white maize with placebo oil (VA-), orange maize with placebo (orange), and white maize with VA in oil [400 μg retinol activity equivalents (RAEs) in 214 μL daily] (VA+).

RESULTS

In total, 133 children completed the trial and were analyzed for TBRs (n = 44 or 45/group). Change in TBR residuals were not normally distributed (P < 0.0001); median changes (95% CI) were as follows: VA-, 13 (-19, 44) μmol; orange, 84 (21, 146) μmol; and VA+, 98 (24, 171) μmol. Nonparametric analysis showed no statistical difference between VA+ and orange (P = 0.34); both were higher than VA- (P = 0.0034). Median (95% CI) calculated liver reserves at baseline were 1.04 (0.97, 1.12) μmol/g liver, with 59% >1 μmol/g, the subtoxicity cutoff; none were <0.1 μmol/g, the deficiency cutoff. The calculated bioconversion factor was 10.4 μg β-carotene equivalents/1 μg retinol by using the middle 3 quintiles of change in TBRs from each group. Serum retinol did not change in response to intervention (P = 0.16) but was reduced with elevated C-reactive protein (P = 0.0029) and α-1-acid glycoprotein (P = 0.0023) at baseline.

CONCLUSIONS

β-Carotene from maize was efficacious when consumed as a staple food in this population and could avoid the potential for hypervitaminosis A that was observed with the use of preformed VA from supplementation and fortification. Use of more sensitive methods other than serum retinol alone, such as isotope dilution, is required to accurately assess VA status, evaluate interventions, and investigate the interaction of VA status and infection. This trial was registered at clinicaltrials.gov as NCT01814891.

The acute phase response affected traditional measures of micronutrient status in rural Zambian children during a randomized, controlled feeding trial

The acute phase response (APR) to infection can alter blood-based indicators of micronutrient status. Data from a 3-mo randomized, controlled feeding trial in rural Zambian children (n = 181, aged 3-5 y) were used to determine the impact of the APR on indicators of vitamin A and iron status using baseline and final blood samples. Concentrations of acute phase proteins were categorized as raised C-reactive protein (CRP; >5 and >10 mg/L) only, both raised CRP and α1-acid glycoprotein (AGP; >1.2 g/L), raised AGP only, and neither CRP nor AGP raised to identify the respective stages of infection: incubation, early convalescence, convalescence, and healthy state. Data were insufficient to examine the incubation stage of infection. A CRP concentration of >5 mg/L was an effective elevation cutoff point in this population to show impact on micronutrient markers. Time did not affect hemoglobin, serum ferritin, or serum retinol concentrations (P > 0.05). During early convalescence, hemoglobin decreased (14-16%; P ≤ 0.05), serum ferritin increased (279-356%; P ≤ 0.05), and serum retinol decreased (20-30%; P ≤ 0.05). Serum retinol concentrations did not change during convalescence; however, hemoglobin remained depressed (4-9%) and serum ferritin was elevated (67-132%) (both P ≤ 0.05). Modified relative dose response values were unaffected by the APR (P > 0.05) but increased between time points (16%; P ≤ 0.05), indicating a decrease in liver vitamin A reserves on the background of a semiannual vitamin A supplementation program. The observed prevalence of anemia and vitamin A deficiency assessed by serum retinol concentration was higher during the APR (P ≤ 0.05). It is important to consider the impact of infection on dietary interventions and to adjust for acute phase proteins when assessing iron status or vitamin A status by serum retinol concentration alone in children.

Maize genotype and food matrix affect the provitamin A carotenoid bioefficacy from staple and carrot-fortified feeds in Mongolian gerbils (Meriones unguiculatus)

Biofortification to increase provitamin A carotenoids is an agronomic approach to alleviate vitamin A deficiency. Two studies compared biofortified foods using in vitro and in vivo methods. Study 1 screened maize genotypes (n = 44) using in vitro analysis, which demonstrated decreasing micellarization with increasing provitamin A. Thereafter, seven 50% biofortified maize feeds that hypothesized a one-to-one equivalency between β-cryptoxanthin and β-carotene were fed to Mongolian gerbils. Total liver retinol differed among the maize groups (P = 0.0043). Study 2 assessed provitamin A bioefficacy from 0.5% high-carotene carrots added to 60% staple-food feeds, followed by in vitro screening. Liver retinol was highest in the potato and banana groups, maize group retinol did not differ from baseline, and all treatments differed from control (P < 0.0001). In conclusion, β-cryptoxanthin and β-carotene have similar bioefficacy; meal matrix effects influence provitamin A absorption from carrot; and in vitro micellarization does not predict bioefficacy.