Synergistic effect of zinc and vitamin A on the biochemical indexes of vitamin A nutrition in children

Abstract

Background: Zinc deficiency limits the bioavailability of vitamin A. Because zinc and vitamin A deficiency often coexist in malnourished children, simultaneous zinc and vitamin A supplementation may improve the vitamin A deficiency in these children. Objective: A randomized, double-blind, placebo-controlled intervention trial was conducted to evaluate whether combining zinc and vitamin A supplementation would improve the biochemical indexes of vitamin A nutriture. Design: Children aged 12-35 mo were randomly assigned to 1 of 4 intervention groups: 20 mg Zn/d for 14 d (Z group), 60 000 retinol equivalents (200 000 IU) vitamin A on day 14 (A group), zinc plus vitamin A (ZA group), or placebo syrup and placebo capsule (placebo group). Venous blood was drawn at enrollment and on day 21. Results: Mean serum retinol concentrations were not significantly different between the A and ZA groups. Among vitamin A-deficient children, the proportion of children who remained vitamin A deficient (serum retinol < 0.7 mol/L) after supplementation was 40.6% in the Z group, 37.5% in the A group, and 47.0% in the placebo group; only 13.3% in the ZA group remained vitamin A deficient (P < 0.05 compared with the placebo group). The proportion of children whose retinol binding protein concentrations remained low was significantly lower in the ZA group than in the other groups (P < 0.05). Conclusion: Combined zinc and vitamin A supplementation improves vitamin A nutriture in vitamin A-deficient children.

Zinc and vitamin A intake and status in a national sample of British young people aged 4–18 y

“…Although plasma RBP concentration was not measured in the present study, its increase or adequacy in relation to Zn status does provide a plausible explanation for an association between plasma Zn and retinol concentrations. This would also be in accordance with evidence of a synergistic effect of Zn and vitamin A on biochemical indices of vitamin A status in children (Rahman et al, 2002).…”

“…Important synergies exist in the functioning of Zn and vitamin A, in relation to growth and development, sexual maturation, immune function; bone, ocular and skin health; and in relation to intestinal absorption and transport (Shils et al, 1999). With regard to the latter interaction, Zn aids vitamin A absorption in the small intestine (Ahn & Koo, 1995), is required for the synthesis of retinol-binding protein (RBP) that transports retinol in plasma and is involved in the exchange of retinol between circulation, target tissues and liver storage (Rahman et al, 2002). Conversely, vitamin A is involved in Zn absorption.…”

Nutrient density score of typical Indonesian foods and dietary formulation using linear programming

“…The challenges to fulfill the RDA of Fe, Zn and vitamin A can be overcome by including those high NAS foods in the regular diet of Indonesians. However, addressing single nutrients became the limitation of this concept because people need several micronutrients, and some of the micronutrients work synergistically (17) . Information on the ED values of Indonesia's commonly consumed foods can be seen in Fig.…”

Cambios en las concentraciones de retinol, hemoglobina y ferritina en niños palúdicos colombianos

“…La falta de efecto del suplemento de retinol y de los antiparasitarios intestinales sobre los cambios en el retinol plasmático en los niños del estudio que estaban altamente parasitados, fue contrario a lo que se ha observado en niños no palúdicos, en quienes los suplementos de retinol aumentaron las concentraciones séricas del mismo y redujeron la prevalencia de deficiencia subclínica de retinol (30,31), lo mismo que la administración de antihelmínticos (32). Las diferencias podrían deberse a que la prevalencia de la deficiencia subclínica de retinol es baja en los niños colombianos habitantes de zonas palúdicas y, en consecuencia, los valores de retinol no mejoran con los suplementos ni con la administración de antihelmínticos.…”