Maternal supplementation and bone growth in infancy.

The effects of maternal supplementation during pregnancy and lactation on bone growth of infants were investigated in 272 mother-infant pairs who participated in the Guatemalan Longitudinal Study of Nutritional Supplementation, Growth and Development. Mothers received one of two nutritional supplements according to village of residence, and bone growth was determined from dimensions of the second metacarpal measured directly from hand-wrist radiographs of 3-month-old infants. Multiple regression analyses indicated significant supplementation effects on cortical bone dimensions related to the volume of supplement intake. These findings were independent of maternal characteristics and attendance at the supplementation centres, and the infant's gender, size, gestational age and morbidity experience. The nutrient composition of the supplements and the patterns of the supplementation effects eliminate proteins, energy, calcium and phosphorus as the nutrients potentially responsible for the bone-specific response. Candidate nutrients for the observed effects are vitamin A, ascorbic acid, niacin, thiamin, iron or fluorine. Presumptive evidence suggests the effects may be due to vitamin A supplementation. These findings suggest opportunities for nutritional intervention in pregnancy and the early postpartum period to prevent osteopaenia in infancy.