Recommended vitamin D intakes for pregnant women may be too low

Prenatal supplement recommendations are too low to ensure vitamin D sufficiency in newborns, particularly for those with darker skin types, says a new study from Italy.

In the observational study, vitamin D concentrations in umbilical cord blood and serum of 62 infants born at term were measured (1). Of the all infants, 32 were born to Italian mothers with fair skin, 30 were born to non-Caucasian mothers, 10 of which had light brown skin and 20 of which had medium brown/black skin. The 30 non-Caucasians had origins stemming from Africa, Asia and Latin America. All mothers of the infants took daily prenatal vitamins which contained 400 IU of vitamin D. The study results showed that the prenatal supplementation was inadequate: infants born to fair skin mothers had a mean vitamin D level of 17.1 ng/ml, infants born to light brown skin mothers had a mean vitamin D level of 8.3 ng/ml and infants born to medium brown skin mothers had a mean vitamin D level of 15.3 ng/ml.

The researchers concluded that a prenatal intake of 400 IU of vitamin D per day – still recommended by some organizations – was inadequate for all offspring of various ethnicities and skin color. Data suggests
that doses exceeding 1000 IU of vitamin D per day are necessary to achieve sufficient vitamin D levels in pregnant women (2). Identifying and treating vitamin D deficiency at birth is essential for preventing diseases later in life, they said.

1. Cadario F. et al. Vitamin D status in cord blood and newborns: ethnic differences. Ital J Pediatr. 2013;
   39(1):35.
2. Wagner C. L. et al. Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents. Pediatrics. 2008; 122:1142–1152.