Double blind, cluster randomised trial of low dose supplementation with vitamin A or βcarotene on mortality related to pregnancy in Nepal

Abstract

Objective: To assess the impact on mortality related to pregnancy of supplementing women of reproductive age each week with a recommended dietary allowance of vitamin A, either preformed or as βcarotene. Design: Double blind, cluster randomised, placebo controlled field trial. Setting: Rural southeast central plains of Nepal (Sarlahi district). Subjects: 44646 married women, of whom 20119 became pregnant 22189 times. Intervention: 270 wards randomised to 3groups of 90each for women to receive weekly a single oral supplement of placebo, vitamin A (7000¼g retinol equivalents) or βcarotene (42mg, or 7000¼g retinol equivalents) for over 31/2 years. Main outcome measures: All cause mortality in women during pregnancy up to 12weekspost partum (pregnancy related mortality) and mortality during pregnancy to 6weeks postpartum, excluding deaths apparently related to injury (maternal mortality). Results: Mortality related to pregnancy in the placebo, vitamin A, and βcarotene groups was 704,426,and 361deaths per 100000 pregnancies, yielding relative risks (95% confidence intervals) of 0.60(0.37to 0.97) and 0.51(0.30to 0.86). This represented reductions of 40% (P<0.04)and 49% (P<0.01) among those who received vitamin A and βcarotene. Combined, vitaminA or βcarotene lowered mortality by 44% (0.56(0.37to 0.84), P<0.005) and reduced the maternal mortality ratio from 645to 385deaths per 100000 live births, or by 40% (P<0.02). Differences in cause of death could not be reliably distinguished between supplemented and placebo groups. Conclusion: Supplementation of women with either vitamin A or βcarotene at recommended dietary amounts during childbearing years can lower mortality related to pregnancy in rural, undernourished populations of south Asia. © 1999, BMJ Publishing Group Ltd. All rights reserved.