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


METHODS
Children aged 12-35 mo were randomly assigned to 1 of 4 intervention groups: 20 mg Zn/d for 14 d (Z group), 60000 retinol equivalents (200000 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 micromol/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).


CONCLUSIONS
Combined zinc and vitamin A supplementation improves vitamin A nutriture in vitamin A-deficient children.
Rahman
Mohammad M
MM
International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.
Wahed
Mohammad A
MA
Fuchs
George J
GJ
Baqui
Abdullah H
AH
Alvarez
Jose O
JO
D000886:Anthropometry; D001459:Bangladesh; D001682:Biological Availability; D016009:Chi-Square Distribution; D002675:Child, Preschool; D019587:Dietary Supplements; D004311:Double-Blind Method; D004357:Drug Synergism; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009752:Nutritional Status; D014801:Vitamin A / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D014802:Vitamin A Deficiency / Q000150:complications / Q000188:drug therapy*; D015032:Zinc / Q000097:blood / Q000172:deficiency* / Q000627:therapeutic use*
D014801:Vitamin A; D015032:Zinc