Zinc supplementation might potentiate the effect of vitamin A in restoring night vision in pregnant Nepalese women.

BACKGROUND: Zinc deficiency may result in abnormal dark adaptation or night blindness, a symptom primarily of vitamin A deficiency. During a placebo-controlled trial in Nepal, weekly vitamin A supplementation of women reduced but failed to eliminate the incidence of night blindness during pregnancy, suggesting a role for zinc. OBJECTIVE: The study examined the efficacy of daily zinc supplementation in restoring night vision of pregnant women who developed night blindness while routinely receiving either vitamin A, beta-carotene, or placebo in a field trial. DESIGN: Women (n = 202) who reported to be night blind during pregnancy were randomly assigned in a double-blind manner, stratified on vitamin A, beta-carotene, or placebo receipt, to receive 25 mg Zn or placebo daily for 3 wk. Thus, the 6 groups studied were as follows: beta-carotene + zinc, beta-carotene alone, vitamin A + zinc, vitamin A alone (vitamin A + placebo), zinc alone (zinc + placebo), and placebo (2 placebos: one for the vitamin A or beta-carotene study and one for the zinc study). Women underwent a clinic-based assessment that included pupillary threshold testing and phlebotomy before and after supplementation. Supplement use and daily history of night blindness were obtained at home twice every week. RESULTS: Zinc treatment increased serum zinc concentrations, but alone (zinc alone group), failed to restore night vision or to improve dark adaptation. However, women in the vitamin A + zinc group who had baseline serum zinc concentrations <9.9 micromol/L were 4 times more likely to have their night vision restored (95% CI: 1.1, 17.3) than were women in the placebo group and tended to have a small improvement in pupillary threshold scores (by 0.21 log candela/m2; P = 0.09). CONCLUSION: These data suggest that zinc potentiated the effect of vitamin A in restoring night vision among night-blind pregnant women with low initial serum zinc concentrations.

Serum retinol levels among preschool children in Central Java: demographic and socioeconomic determinants.

BACKGROUND: Vitamin A deficiency is a significant problem in many countries in the developing world. Reports have noted demographic and socioeconomic risk factors for vitamin A deficiency. 'Deficiency' has usually been defined by clinical signs and symptoms which represent only a small proportion of those children at increased risk for vitamin A preventable morbidity and mortality. METHODS: As part of a population-based trial of vitamin A to prevent childhood morbidity, we collected census data (n = 666), baseline socioeconomic data (n = 636) and sera (n = 666) from children aged 6-48 months in 25 adjacent villages in a rural area in Central Java, Indonesia; there was more than 95% participation. We used t tests, ANOVA, and a multiple variable linear regression model in our analyses. RESULTS: Differences in mean retinol level were detected for the following variables: village (P < 0.001), child's age (P = 0.03), size of sibship (P < 0.001), mother's occupation (P < 0.01), mother's education (P = 0.05), father's education (P = 0.03), monthly household earnings (P = 0.02), land ownership (P = 0.03), possession of ducks (P = 0.06), radio or tape player (P = 0.02), or a watch or clock (P = 0.07), and presence of a natural well (P = 0.09). Our regression model verified the predictive value of village, age, sibship, land ownership and earnings. CONCLUSIONS: We found that owning land and that the highest and lowest categories of reported household income were associated with higher serum retinol levels. We also noted clustering of serum retinol levels by village and discovered that children from larger sibships and infants had significantly lower serum retinol levels. Vitamin A supplementation of lactating mothers, particularly of high parity, and/or their infants should be considered.

PIP: Vitamin A deficiency is a significant problem in many countries in the developing world. Reports have noted demographic and socioeconomic risk factors for vitamin A deficiency. As part of a population-based trial of vitamin A to prevent childhood morbidity, census data (n = 666), baseline socioeconomic data (n = 636) and sera (n = 666) were collected from children 6-48 months old in 25 adjacent villages in a rural area in Central Java, Indonesia. Participation amounted to more than 95%. The analyses used t tests, ANOVA, and a multiple variable linear regression model. The distribution of serum retinol levels (in mcmol/l) in males shifted to the left relative to females, resulting in a higher proportion of males with a level 0.70 mcmol/l (20 mcg/dl); 216/346 males versus 173/320 females (p = 0.03). However, there was no significant difference in the means by gender. Differences in mean retinol level were detected for the following variables: village (p 0.001); child's age (p = 0.03); size of sibship (p 0.001); mother's occupation (p 0.01); mother's education (p = 0.05); father's education (p = 0.03); monthly household earnings (p = 0.02); land ownership (p = 0.03); possession of ducks (p = 0.06), radio or tape player (p = 0.02), or a watch or clock (p = 0.07); and presence of a natural well (p = 0.09). There was no significant difference in mean serum retinol level for mother's marital status; father's occupation; monthly household expenditures; house ownership; composition of floors, walls, or roofs; or possession of buffaloes, cattle, goats, kerosene light fixtures, televisions, or motorcycles. The regression model verified the predictive value of village, age, sibship, land ownership, and earnings. Owning land and the highest and lowest categories of reported household income were associated with higher serum retinol levels. Also clustering of serum retinol levels was noted by village, and children from larger sibships and infants had significantly lower serum retinol levels. Vitamin A supplementation of lactating mothers, particularly of high parity, and/or their infants should be considered.

Evaluation of a maize-cowpea-palm oil diet for the dietary management of Nigerian children with acute, watery diarrhea.

A randomized clinical trial was carried out to compare a locally available maize-cowpea-palm oil diet (group MCP) with a commercially produced lactose-free, soy protein isolate formula (group SF) for the dietary management of 69 Nigerian boys, 6-24 months of age, hospitalized for acute, watery diarrhea. Although the treatment groups were generally similar initially, the children in group SF had slightly lower mean weight-for-age z scores (p = 0.08), lower serum bicarbonate levels (p = 0.04) and greater stool outputs during the period of rehydration before the diets were initiated (p = 0.01). Rates of treatment failure in group MCP (5.7%) and group SF (8.8%) were similar (p = 0.67). There were no significant differences in the adjusted mean stool outputs by study group on days 1-5, but the children in group SF had slightly lower fecal weights on day 6 (p = 0.05). Children in group MCP had a substantially reduced duration of liquid stool excretion (estimated median duration 42 h versus 140 h; p < 0.001). On the other hand, children in group SF consumed considerably more of their diet, had greater net absorption of macronutrients and greater rates of weight gain than those in group MCP. We conclude that children can safely consume the MCP diet during acute, watery diarrhea without increasing their risk of treatment failure or augmenting stool output. However, the diet may not be adequate as a sole source of nutrients beyond the period of acute illness.