RESUMO
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.
Assuntos
Dieta/métodos , Carne , Inquéritos Nutricionais/estatística & dados numéricos , Estado Nutricional , Deficiência de Vitamina A/prevenção & controle , Vitamina A/sangue , Animais , Pré-Escolar , Feminino , Humanos , Fígado , Masculino , Inquéritos Nutricionais/métodos , Ovinos , África do SulRESUMO
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.
Assuntos
Dieta , Alimentos Fortificados , Hipervitaminose A/sangue , Fígado , Ovinos , Vitamina A/administração & dosagem , Animais , Pré-Escolar , Suplementos Nutricionais , Alimentos Fortificados/análise , Humanos , Fígado/química , África do Sul , Vitamina A/análise , Vitamina A/sangueRESUMO
OBJECTIVE: To assess the contribution of liver to the vitamin A intake of 24-59-month-old children from an impoverished South African community where liver is frequently consumed and vitamin A deficiency previously shown to be absent. DESIGN: Cross-sectional. SETTING: Northern Cape Province, South Africa. SUBJECTS: Children aged 24-59 months (n 150). Vitamin A intake from liver was assessed using a single 24 h recall and a quantified liver frequency questionnaire. In addition, information on vitamin A intake via the national fortification programme was obtained from the 24 h recall and information on vitamin A supplementation from the Road-to-Health Chart. Height, weight and socio-economic data were also collected. RESULTS: Stunting, underweight and wasting were prevalent in 36·9 %, 25·5 % and 12·1 % of children. Mean daily vitamin A intake from liver was 537 and 325 µg retinol equivalents measured by the 24 h recall and liver frequency questionnaire, respectively. Liver was consumed in 92·7 % of households and by 84·7 % of children; liver intake was inversely related to socio-economic status (P < 0·05). The food fortification programme contributed 80 µg retinol equivalents and the vitamin A supplementation programme 122 µg retinol equivalents to daily vitamin A intake. CONCLUSIONS: The study showed that liver alone provided more than 100 % of the Estimated Average Requirement of the pre-school children in this impoverished community. The results also challenge the notion generally held by international health bodies that vitamin A deficiency, poor anthropometric status and poverty go together, and reinforces the fact that South Africa is a culturally diverse society for which targeted interventions are required.