Liver intake in 24-59-month-old children from an impoverished South African community provides enough vitamin A to meet requirements

Total Liver Vitamin A Reserves, Determined With 13C2-Retinol Isotope Dilution, are Similar Among Tanzanian Preschool Children in Areas With Low and High Vitamin A Exposure

BACKGROUND

In Tanzania, some districts have single vitamin A (VA) interventions and others have multiple interventions. There is limited information on total liver VA reserves (TLRs) among preschool children (PSC) in Tanzania.

OBJECTIVES

We assessed total body VA stores (TBSs) and TLRs among PSC living in 2 districts with low and high exposures to VA interventions using 13C-retinol isotope dilution.

METHODS

A cross-sectional, health facility-based study was conducted in 2 districts with access to VA supplementation only (low exposure to VA interventions) or multiple interventions (high exposure to VA interventions) to determine TLRs in 120 PSC aged 36-59 months. A questionnaire was used to collect data. Height and weight were measured, and the prevalence of undernutrition was based on z-scores. Blood samples were collected for measurement of TBSs, TLRs, retinol, biomarkers of infection and inflammation, and hemoglobin. 13C2-retinyl acetate (1.0 μmol) was administered to each child after blood collection, and the second sample was taken 14 days later. Serum was analyzed with HPLC and gas chromatography-combustion-isotope ratio mass spectrometry. Mann-Whitney U test was used to compare medians of nonnormally distributed variables. Pearson χ2 test was used to assess associations between 2 categorical variables.

RESULTS

Median TBSs differed between PSC from low-exposure (196 μmol; IQR, 120 μmol) and high-exposure (231 μmol; IQR, 162 μmol) intervention areas (P = 0.015). Median TLRs were 0.23 μmol/g liver (IQR, 0.14 μmol/g liver) and 0.26 μmol/g liver (IQR, 0.16 μmol/g liver) from low- and high-exposure areas, respectively, which did not significantly differ (P = 0.12). Prevalences of VA deficiency (VAD; ≤0.1 μmol/g liver) were 6.3% and 1.7% for PSC from low- and high-exposure areas, respectively. There was no significant difference in VAD (P = 0.25). No child had hypervitaminosis A (≥1.0 μmol/g liver).

CONCLUSIONS

TLRs in Tanzanian PSC from 2 districts did not differ between low and high exposures to VA interventions. The majority had adequate VA stores. VAD in the study area presented a mild public health problem.

Chronic and acute hypervitaminosis A are associated with suboptimal anthropometric measurements in a cohort of South African preschool children

BACKGROUND

Excessive vitamin A (VA) can cause bone resorption and impair growth. Government-mandated VA supplementation (VAS) and adequate intake through dietary fortification and liver consumption led to excessive VA in South African children.

OBJECTIVES

We evaluated the relation between VAS and underlying hypervitaminosis A assessed by retinol isotope dilution (RID) with measures of growth and bone turnover in this cohort.

METHODS

Primary outcomes in these children (n = 94, 36-60 mo) were anthropometric measurements [height-for-age (HAZ), weight-for-age (WAZ), and weight-for-height (WHZ) z scores], serum bone turnover markers [C-terminal telopeptide of type I collagen (CTX) and N-terminal propeptide of type I procollagen (P1NP)], and inflammation defined as C-reactive protein (CRP; ≥5 mg/L) and/or α1-acid glycoprotein (AGP; ≥1 g/L). VA status was previously measured by RID-estimated total body VA stores (TBSs) and total liver VA reserves (TLRs), and serum retinol and carotenoid concentrations, before and 4 wk after children were administered 200,000 IU VAS. Serum 25-hydroxyvitamin D3 was measured by ultra-performance LC.

RESULTS

In this largely hypervitaminotic A cohort, HAZ, WAZ, and WHZ were negatively associated with increasing TLRs, where TLRs predicted 6-10% of the variation before VAS (P < 0.05), increasing to 14-19% 4 wk after VAS (P < 0.01). Bone resorption decreased after VAS (P < 0.0001), whereas formation was unaffected. Neither CTX nor P1NP were correlated with TLRs at either time. Serum carotenoids were low. One child at each time point was vitamin D deficient (<50 nmol/L). CRP and AGP were not associated with growth measurements.

CONCLUSIONS

Excessive TLRs due to dietary VA intake and VAS are associated with lower anthropometric measures and bone resorption decreased after supplementation. VA supplementation programs should monitor VA status with biomarkers sensitive to TLRs to avoid causing negative consequences in children with hypervitaminosis A. This trial is registered at clinicaltrials.gov as NCT02915731.

Mean ± Standard Deviation Intake Values for 1–<10-Year-Old South African Children for Application in the Assessment of the Inflammatory Potential of Their Diets Using the DII® Method: Developmental Research

This study aimed to develop a set of mean ± standard deviation (SD) intake values for South African (SA) children for 36 of the 45 food parameters included in the original Dietary Inflammatory Index (DII^®) tool. The SA food composition database contains 30 of the 45 food parameters included in the original DII^®, and a supplementary database was developed for six of the food parameters not included in the SA database. The SA child mean ± SD intake of macronutrients, micronutrients and select flavonoids was calculated by age in years, using eight data sets from dietary surveys conducted in SA in the last three decades. A total sample of 5412 children was included in the calculation of the mean ± SD. The current study sample was determined to be representative of 1–<10-year-old children in SA, and the plausibility of the mean intake values was confirmed by being in line with age-appropriate recommendations. Furthermore, an increase in energy, macronutrient, and most micronutrient intakes with increase in age was evident. The generated mean ± SD values for SA children can be used for calculation of the inflammatory potential of the dietary intake of SA children in the age range of 1–<10-year-old children.

Liver is widely eaten by preschool children in the Northern Cape province of South Africa: Implications for routine vitamin A supplementation

Previous research has demonstrated a virtual absence of vitamin A deficiency and adequacy of vitamin A intake through consumption of liver in preschool children of a community in the Northern Cape province of South Africa where sheep farming is common, and liver, an exceptionally rich source of vitamin A, is frequently eaten. Only 60-75 g of liver per month is needed to meet the vitamin A requirement of preschool children. Because this may have implications for routine vitamin A supplementation, and because liver consumption for the rest of the province is unknown, the study aim was to establish the prevalence and frequency of liver intake in a provincial-wide survey. An unquantified liver-specific food frequency questionnaire, covering a period of 1 month, complemented by a 1-year recall, was administered to mothers of 2- to 5-year-old children (n = 2,864) attending primary health care facilities in all five districts and 26 subdistricts. A total of 86% of children were reported to eat liver, which was eaten in all districts by at least 80% of children. The overall median frequency of liver intake was 1.0 [25th, 75th percentiles: 0.5, 3.0] times per month and ranged from 1.0 [0.3, 2.0] to 2.0 [1.0, 4.0] for the various districts. Based on a previously reported portion size of 66 g, these results suggest vitamin A dietary adequacy in all districts and possibly also vitamin A intake exceeding the Tolerable Upper Intake Level in some children. Routine vitamin A supplementation in this province may not be necessary and should be reconsidered.

Meat, fruit, and vegetable consumption in sub-Saharan Africa: a systematic review and meta-regression analysis

CONTEXT

The dietary choices people make affect personal health and have consequences for the environment, both of which have serious implications for the 2030 Sustainable Development Agenda. In global reviews, the literature on meat, fruit, and vegetable consumption in sub-Saharan Africa (SSA) is limited.

OBJECTIVE

This systematic review set out to quantify meat, fruit, and vegetable consumption in SSA populations and to answer the following question: How much meat, fruit, and/or vegetables are being consumed daily by which individuals in SSA over the years?

DATA SOURCES

Following the PRISMA guidelines, the authors systematically searched the MEDLINE, EMBASE, ASSIA CINAHL, Web of Science, POPLINE, and Google Scholar databases to identify 47 (out of 5922 search results) studies reporting meat, fruit, and/or vegetable consumption in SSA populations.

DATA EXTRACTION

Three independent investigators extracted data on year of data collection, study country, study population and geographical context, and population intake of meat, fruit, and/or vegetables.

DATA ANALYSIS

Using STATA SE version 15 software, random-effects meta-regression analyses were used to test the effect of year of data collection and method of data collection on population meat, fruit, and vegetable consumption. The analyses also tested any association between age, sex, rural/urban residence, or a country's economic development and population intake of meat, fruits, and/or vegetables. The review was started in 2017 and completed in 2019.

RESULTS

Richer SSA countries were likely to consume more meat (ß = 36.76, P = 0.04) and vegetables (ß =43.49, P  = 0.00) than poorer countries. Vegetable intake has increased dramatically over the last 3 decades from ≈10 g to ≈110 g (ß = 4.43, P  = 0.00). Vegetable (ß= -25.48, P  = 0.00) consumption was higher in rural than in urban residents. Although the trend of meat consumption has risen (≈25 g to ≈75 g), the trend is nonsignificant (ß = 0.63, N.S.). Daily average per capita meat consumption was 98 g - above the 70 g recommendation - while fruit and vegetable intake (268 g) remain below the World Health Organization's recommendation (400 g).

CONCLUSIONS

Given the low intake of plant-based foods, it is likely that SSA populations may be deficient in high-quality protein and micronutrients as suggested by the EAT-Lancet Commission. There is a need to promote both an adequate supply and demand of plant-based protein and micronutrients, including fruit, vegetables, nuts, seeds, and legumes, in SSA countries. While dietary changes in SSA may offer large absolute benefits, consideration of the magnitude of dietary change, particularly increasing or reducing meat consumption, will need to occur in a way that ensures that policy and interventions support the reduction of undernutrition and micronutrient deficiencies without worsening the prevalence and environmental impacts of noncommunicable diseases. There is also the need for preventive action that ensures that SSA populations do not increase their meat consumption as disposable incomes increase and countries' economic development rises, as is seen in most countries undergoing economic transformation.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018090497.

South African preschool children habitually consuming sheep liver and exposed to vitamin A supplementation and fortification have hypervitaminotic A liver stores: a cohort study

BACKGROUND

In some regions, multiple vitamin A (VA) interventions occur in the same target groups, which may lead to excessive stores. Retinol isotope dilution (RID) is a more sensitive technique than serum retinol to measure VA status.

OBJECTIVE

We evaluated VA status before and after a high-dose supplement in preschool children living in a region in South Africa with habitual liver consumption and exposed to VA supplementation and fortification.

METHODS

After baseline blood samples, subjects (46.7 ± 8.4 mo; n = 94) were administered 1.0 μmol [14,15]-13C2-retinyl acetate to estimate total liver retinol reserves by RID with a follow-up 14-d blood sample. Liver intake was assessed with a frequency questionnaire. In line with current practice, a routine 200,000 IU VA capsule was administered after the RID test. RID was repeated 1 mo later. Serum retinyl esters were evaluated using ultra-performance liquid chromatography.

RESULTS

At baseline, 63.6% of these children had hypervitaminosis A defined as total liver retinol reserves ≥1.0 μmol/g liver, which increased to 71.6% after supplementation (1.13 ± 0.43 to 1.29 ± 0.46 μmol/g; P < 0.001). Total serum VA as retinyl esters was elevated in 4.8% and 6.1% of children before and after supplementation. The odds of having hypervitaminosis A at baseline were higher in children consuming liver ≥1/mo (ratio 3.70 [95% CI: 1.08, 12.6]) and in children receiving 2 (4.28 [1.03, 17.9]) or 3 (6.45 [0.64, 65.41]) supplements in the past 12 mo. Total body stores decreased after the supplement in children in the highest quartile at baseline compared with children with lower stores, who showed an increase (P = 0.007).

CONCLUSIONS

In children, such as this cohort in South Africa, with adequate VA intake through diet, and overlapping VA fortification and supplementation, preschool VA capsule distribution should be re-evaluated. This trial was registered at https://clinicaltrials.gov/ct2/show/NCT02915731 as NCT02915731.

Overlapping vitamin A interventions in the United States, Guatemala, Zambia, and South Africa: case studies

Vitamin A (VA) deficiency is a serious public health problem, especially in preschool children who are at risk of increased mortality. In order to address this problem, the World Health Organization recommends periodic high-dose supplementation to children 6-59 months of age in areas of highest risk. Originally, supplementation was meant as a short-term solution until more sustainable interventions could be adopted. Currently, many countries are fortifying commercialized common staple and snack foods with retinyl palmitate. However, in some countries, overlapping programs may lead to excessive intakes. Our review uses case studies in the United States, Guatemala, Zambia, and South Africa to illustrate the potential for excessive intakes in some groups. For example, direct liver analysis from 27 U.S. adult cadavers revealed 33% prevalence of hypervitaminosis A (defined as ≥1 μmol/g liver). In 133 Zambian children, 59% were diagnosed with hypervitaminosis A using a retinol isotope dilution, and 16% had ≥5% total serum VA as retinyl esters, a measure of intoxication. In 40 South African children who frequently consumed liver, 72.5% had ≥5% total serum VA as retinyl esters. All four countries have mandatory fortified foods and a high percentage of supplement users or targeted supplementation to preschool children.

Micronutrient Status and Dietary Intake of Iron, Vitamin A, Iodine, Folate and Zinc in Women of Reproductive Age and Pregnant Women in Ethiopia, Kenya, Nigeria and South Africa: A Systematic Review of Data from 2005 to 2015

A systematic review was conducted to evaluate the status and intake of iron, vitamin A, iodine, folate and zinc in women of reproductive age (WRA) (≥15–49 years) and pregnant women (PW) in Ethiopia, Kenya, Nigeria and South Africa. National and subnational data published between 2005 and 2015 were searched via Medline, Scopus and national public health websites. Per micronutrient, relevant data were pooled into an average prevalence of deficiency, weighted by sample size (WAVG). Inadequate intakes were estimated from mean (SD) intakes. This review included 65 surveys and studies from Ethiopia (21), Kenya (11), Nigeria (21) and South Africa (12). In WRA, WAVG prevalence of anaemia ranged from 18–51%, iron deficiency 9–18%, and iron deficiency anaemia at 10%. In PW, the prevalence was higher, and ranged from 32–62%, 19–61%, and 9–47%, respectively. In WRA, prevalence of vitamin A, iodine, zinc and folate deficiencies ranged from 4–22%, 22–55%, 34% and 46%, while in PW these ranged from 21–48%, 87%, 46–76% and 3–12% respectively. Inadequate intakes of these micronutrients are high and corresponded with the prevalence figures. Our findings indicate that nationally representative data are needed to guide the development of nutrition interventions and public health programs, such as dietary diversification, micronutrient fortification and supplementation.

Serum retinol in post-partum mothers and newborns from an impoverished South African community where liver is frequently eaten and vitamin A deficiency is absent

Serum retinol was assessed in mothers and newborns from an impoverished South African community where liver is frequently eaten and vitamin A deficiency known to be absent. Paired cord and maternal blood (n = 201) were collected after delivery and analysed for serum retinol and C-reactive protein (CRP). Liver intake during pregnancy and intention to breastfeed were also assessed. Mean serum retinol was 1.03 µmol/L ± 0.40 in mothers and 0.73 ± 0.24 µmol/L in newborns, with 21.4% and 49.3% having serum retinol <0.70 µmol/L (<20 µg/dL), respectively. Raised CRP was found in 59.9% of mothers, with a significant negative correlation between serum retinol and CRP (r = -0.273; p < 0.0001). Liver was eaten by 87.6% of mothers, and 99% indicated their intention to breastfeed. Despite consumption of liver, serum retinol was low in both the mother and the newborn. The conventional cut-off for serum retinol, i.e. <0.70 µmol/L may therefore not apply for the mother and newborn in the period immediately after delivery. Serum retinol may be influenced by factors other than vitamin A status, e.g. the haemodilution of pregnancy, as well as the acute phase response induced by the birth process, as suggested by raised CRP in 60% of mothers. In the newborns, the low serum retinol is likely to increase rapidly, as liver is frequently eaten by mothers and practically all of them intended to breastfeed. Our results confirm the need for better indicators of vitamin A status or alternative cut-off values during this period.