To determine whether zinc deficiency might be involved in the failure to thrive observed in undernourished Vietnamese children, we assessed growth, incidence of infections, and circulating insulin-like growth factor I (IGF-I) concentrations in a double-blind study of zinc supplementation. Growth-retarded children (n=146) aged 4-36 mo were paired according to age, sex, commune, Z scores for weight (WAZ) and for height (HAZ), and number of siblings, and were randomly assigned to receive either 153 micromol (10 mg) Zn/d or a placebo for 5 mo. Weight, height, and episodes of infection were recorded each month and plasma IGF-I was measured 1 and 5 mo after the start of zinc supplementation. Multiple-linear-regression analysis for paired data showed that zinc supplementation increased weight (+0.5 +/- 0.1 kg; P<0.001) and height (+1.5+/-0.2 cm; P<0.001) after 5 mo compared with placebo treatment. The relative risk of infectious episodes in the zinc-treated subjects was reduced 3-fold for diarrhea (P=0.012) and 2.5-fold for respiratory infections (p=0.057). The probability of having at least two episodes of diarrhea or respiratory infection was 2.9- and 3.2-fold lower, respectively, in zinc-treated subjects between 1 and 5 mo (P=0.018), whereas they did not change in placebo-treated subjects (P-0.584). After 1 mo, IGF-I concentration (-x+/-SD) in zinc-treated subjects was 2.8+/-0.3 nmol/L compared with 1.9+/-0.2 nmol/L in placebo-treated subjects (P=0.021). After 5 mo, the values were 3.4+/-0.5 nmol/L (zinc-treated) and 2.0+/-0.3 nmol/L (placebo-treated; P=0.044). Our study suggests that zinc deficiency may limit growth in nutritionally deprived children. Because the increase in growth velocity resulting from zinc supplementation was associated with increased plasma IGF-I concentrations, we suggest that the growth-stimulating effect of zinc might be mediated through changes in circulating IGF-I.

Regular consumption of iron-fortified fish sauce significantly reduced the prevalence of iron deficiency anemia in Vietnamese women during the 6-mo intervention. Fortifying fish sauce with iron by using a water-soluble, highly bioavailable compound (NaFeEDTA) is a promising strategy for combating iron deficiency anemia in Vietnam.

Background: Micronutrient deficiencies remain common in preschool children in developing countries. Interventions focus on single micronutrients and often lack effectiveness. Weekly instead of daily supplementation may improve effectiveness. Objective: The efficacy of weekly and daily supplementation in reducing anemia prevalence and in improving the zinc, vitamin A, and growth status of 6-24-mo-old Vietnamese children was investigated. Design: In this double-blind, placebo-controlled trial, the daily group (n = 55) received 8 mg elemental Fe (as iron sulfate), 5 mg elemental Zn (as zinc sulfate), 333 g retinol, and 20 mg vitamin C 5 d/wk for 3 mo. The weekly group (n = 54) received 20 mg Fe, 17 mg Zn, 1700 g retinol, and 20 mg vitamin C once a week. A third group (n = 54) received a placebo only. Venous blood samples were collected at the start and end of the supplementation period and anthropometric measurements were taken at the start and 3 mo after the end of supplementation. Results: At baseline, 45.6% of subjects had hemoglobin concentrations < 110 g/L, 36.3% had zinc concentrations < 10.71 mol/L, and 45.6% had retinol concentrations < 0.70 mol/L. Hemoglobin, retinol, and zinc concentrations of both the weekly and daily groups increased similarly compared with the placebo group (P < 0.001). There was no significant difference in growth between the supplemented groups and the placebo group. However, the height-for-age of subjects stunted at baseline increased with z scores of 0.48 (P < 0.001) and 0.37 (P < 0.001) for the daily and weekly groups, respectively. Conclusions: Weekly and daily supplementation improved hemoglobin, zinc, and retinol concentrations similarly. Neither intervention affected growth of the overall population, but growth of children stunted at baseline was improved through both types of supplementation.Am J Clin Nutr 1999;69:80-6.