Objective To determine the effects of maternal vitamin A supplementation from preconception through postpartum on cognitive and motor development of children at 10–13 years of age in rural Nepal.

Design Follow-up assessment of children born to women randomly assigned by a village to receive either supplemental vitamin A (7000 µg retinol equivalents) or placebo weekly during a continuous 3.5-year period from 1994–1997. The participants came from 12 wards, a subset of 270 wards in the original trial. Trained staff tested children for cognition by the Universal Nonverbal Intelligence Test (UNIT) and motor ability using four subtests from the Movement Assessment Battery for Children (MABC). Data on schooling, home environment and nutritional and socioeconomic status were also collected.

Setting Southern plains district of Sarlahi, Nepal.

Participants 390 Nepalese children 10–13 years of age.

Main outcome measures Raw scores on UNIT and square-root transformed scores on an abridged version of the MABC tests, expressed as cluster-summarised (mean±SD) values to account for the design of the original trial.

Results There were no differences in UNIT (79.61±5.99 vs 80.69±6.71) or MABC (2.64±0.07 vs 2.49±0.09) test scores in children whose mothers were exposed to vitamin A vs placebo (mean differences: −1.07, 95% CI −7.10 to 9.26, p=0.78; 0.15, 95% CI 0.43 to −0.08, p=0.15), respectively. More children in the placebo group had repeated a grade in school (28% of placebo vs 16.7% of vitamin A, p=0.01).

Conclusions Preconceptional to postpartum maternal vitamin A supplementation, in an undernourished setting, does not improve cognition or motor development at ages 10–13 years.