Plasma 25-hydroxyvitamin D in pregnant Asian women and their babies.

Plasma 25-hydroxyvitamin D (25-OHD) was measured in cord blood taken at delivery and in fasting blood taken from 44 Asian mothers in the first day of the puerperium. Blood was taken from the baby 48 h after delivery. Cord-blood samples were also taken at 43 non-Asian deliveries. Plasma 25-OHD concentrations in Asians were low at delivery; in 81% of the mothers and 36% of the babies plasma 25-OHD was in the osteomalacic range. Asian lower than concentrations in non-Asian controls. 4 Asian babies had vraniotabes and 1 had neonatal tetany. 1 non-Asian baby had craniotabes. A review of 3327 deliveries in 1978 confirmed that neonatal tetany was significantly more common in Asian babies (2.3%) than in non-Asian babies (0.3%). In 44 other Asian mothers supplements of 1000 units of vitamin D daily during pregnancy significantly increased plasma-25-OHD concentrations at delivery.