The effects of maternal and infant vitamin A supplementation on vitamin A status: a randomised trial in Kenya

Randomized, double-blind, placebo-controlled 2x2 factorial trial in postpartum mother-infant pairs from rural western Kenya (Bondo District, Lake Victoria shore). Mothers were enrolled after live delivery and assigned to maternal vitamin A, infant vitamin A, both, or placebo.

Mothers in the active arms received 400,000 IU vitamin A orally as two 200,000 IU oily capsules within 24 hours postpartum. Infants in the active arms received 100,000 IU vitamin A orally as one oily capsule at 14 weeks of age. The trial used placebo capsules in the corresponding control arms in a 2x2 factorial design.

Maternal vitamin A did not meaningfully improve maternal serum retinol, but it modestly increased breast milk retinol; infant vitamin A improved infant vitamin A stores by MRDR, yet did not increase infant serum retinol, and combining maternal plus infant supplementation did not show a clear added benefit. In mothers, the serum retinol difference for vitamin A versus placebo was 0.04 (95% CI 0.01 to 0.09; P=0.13) at week 14 postpartum and -0.02 (95% CI -0.08 to 0.04; P=0.50) at week 26 postpartum. Infant supplementation reduced MRDR ratios by -0.012 (95% CI -0.019 to -0.005) and lowered the odds of high MRDR ratios, but these comparisons were not statistically definitive (OR 0.66, 95% CI 0.41 to 1.05; P=0.08; OR 0.56, 95% CI 0.30 to 1.05; P=0.07). There was no mortality difference, and bulging fontanels were uncommon (4 infants on placebo vs 8 on vitamin A; P=0.26).

The main findings rely on surrogate biomarkers rather than clinical deficiency outcomes or morbidity benefits. Follow-up was limited to 26 weeks postpartum, and analyzable sample sizes were smaller at later time points, reducing power. Generalizability is limited to postpartum women and infants in rural western Kenya with substantial infectious and nutritional burden.