Ensuring an adequate vitamin A intake amongst pregnant women in a population with chronic vitamin A deficiency led to improved lung function in the children, according to a new study published in the New England Journal of Medicine.
Children of mothers who received beta-carotene supplements did not experience any benefits, relative to placebo, however.
“The greater bioefficacy of preformed vitamin A as compared with beta carotene may stem from differences in absorption and metabolism,” explained the researchers, led by William Checkley, MD, PhD from the Johns Hopkins School of Medicine.
“The lower bioefficacy of the beta-carotene supplement as a source of vitamin A in the mothers and their offspring in our trial was also evident in the finding that serum retinol concentrations in mothers at mid-pregnancy and post partum and in their infants at 3 months of age were lower among those in the beta-carotene group than they were among those in the preformed–vitamin A group,” they added.
Vitamin A deficiency (VAD) is a public health problem in more than 50 per cent of all countries, especially in Africa and South-East Asia, according to the World Health Organisation, and causes blindness in up to 500,000 children each year. The World Bank has declared vitamin A supplementation as one of the most cost-effective interventions of all time.
Checkley and his co-workers analysed lung function in 1,371 Nepalese children aged between 9 and 13 whose mothers had taken part in a placebo-controlled, double-blind, cluster-randomized trial of vitamin A or beta-carotene supplementation between 1994 and 1997.
Using a portable pneumatochometer, the researchers found that children whose mothers received vitamin A instead of a placebo had a 46 millilitres higher forced expiratory volume at one second (FEV1) and a 14 ml higher forced vital capacity (FVC), compared with children whose mothers received beta-carotene and placebo.
“Lung function of offspring in mothers who received maternal vitamin A supplementation improved by about 40 ml versus those whose mothers received a placebo,” said Checkley. “This represents an approximately 3 per cent increase in lung function. Furthermore, the magnitude of effect observed in this study is slightly greater than that associated with preventing exposure to parental smoking in school-age children.”
“Improved lung function was likely specific to supplementation received in utero because this population of children was subsequently exposed beyond six months of age to semiannual vitamin A supplementation with high coverage as part of a national program during their preschool years,” said co-author Keith West from the Bloomberg School’s Department of International Health.
“This benefit was limited to children whose mothers received vitamin A and not to those whose mothers received beta-carotene. Early interventions with vitamin A in communities where undernutrition is highly prevalent may have long-lasting consequences in lung health.”
Source: New England Journal of Medicine
May 2010, Volume 362, Number 19, Pages 1784-
“Maternal Vitamin A Supplementation and Lung Function in Offspring”
Authors: W. Checkley, K.P. West, R.A. Wise, M.R. Baldwin, L. Wu, S.C. LeClerq, P. Christian, J. Katz, J.M. Tielsch, S. Khatry, A. Sommer