Perinatal vitamin A (retinol) status of northern Canadian mothers and their infants.

Vitamin A (retinol) status was determined in two groups living in the northern part of Canada: native (Indian and Inuit) and non-native (Caucasian). The dietary intake of vitamin A and its plasma concentration were measured prenatally, at delivery and postnatally in mothers. Plasma concentrations were also measured at birth and postnatally in their infants. The mean vitamin A intake of native mothers was significantly lower than that of non-native mothers, 661 +/- 485 versus 1,377 +/- 1,418 retinol equivalents (p < 0.00005), with a higher risk of deficiency without supplementation, 35% versus 8%. Plasma retinol concentrations, although not in the deficient range, were significantly lower in native than non-native mothers prenatally and postnatally. Infant mean plasma retinol concentrations at birth averaged only 52% of those of their mothers and were significantly lower among native than non-native infants although no clinical evidence of vitamin A deficiency was noted. We speculate that vitamin A supplementation in native Northern Canadian mothers during pregnancy and in their neonates during infancy may have a role to play in the prevention of vitamin A deficiency. We also postulate that plasma retinol concentrations of 50-60% of maternal levels and between 0.7 and 2.5 mumol/l represent a 'normal' range for newborn infants.