VITAMIN-A OR BETA-CAROTENE SUPPLEMENTATION REDUCES BUT DOES NOT ELIMINATE MATERNAL NIGHT BLINDNESS IN NEPAL

We investigated the effect of supplementing women weekly with 7000 mu g retinol equivalents as preformed vitamin A or beta-carotene vs. a pl acebo, on the incidence of night blindness during pregnancy and the po stpartum period in the rural plains of Nepal. Over a period of similar to 3 y, similar to 29,000 women of child-bearing age, living in 171 w ards that were randomized to one of the three supplements, contributed 9932 first pregnancies. A prospective, weekly surveillance identified night blindness in pregnant women, verified further by detailed quest ioning about nighttime vision. After delivery, women were also intervi ewed at similar to 3 and similar to 6 mo postpartum to elicit a night blindness history over the preceding 3 mo. Vitamin A supplementation r educed the incidence of night blindness during pregnancy from 10.7% am ong controls to 6.7% (relative risk 0.62, 95% confidence interval: 0.4 5-0.85). beta-Carotene supplementation had less of an effect (0.83, 0. 63-1.11). Among women who took >95% of their vitamin A supplements dur ing pregnancy, incidence of verified night blindness was reduced by 67 %. Incidence (per 100 person-years) of night blindness during the firs t 3 mo postpartum was 11.3 in the control, 4.3 in the vitamin A and 8. 7 in the beta-carotene groups, yielding corresponding relative risks o f 0.38 (0.26-0.55) and 0.77 (0.57-1.04). In the second 3 mo postpartum , both vitamin A and beta-carotene reduced night blindness by similar to 50%. Vitamin A intakes approaching a recommended amount for pregnan cy markedly reduced but did not eliminate night blindness in Nepali wo men. Greater intakes of vitamin A than provided and/or other nutrients may be needed to prevent maternal night blindness in rural South Asia .