Comparison between maternal and neonatal serum vitamin D levels in term jaundiced and nonjaundiced cases

Neonatal jaundice is the result of an imbalance between the production and conjugation of bilirubin. Considering the multiple roles of vitamin D, lower levels of vitamin D in these cases may be associated with neonatal jaundice. The present study was undertaken for the purpose of comparing serum vitamin D levels in healthy term jaundiced and nonjaundiced newborns and their mothers.

This case-control study was conducted in 60 term newborns and their mothers from a teaching and referral children's hospital in the southwestern region of Iran, from December 22, 2013 through March 22, 2014. Neonatal and maternal blood samples were obtained and sent to the laboratory.

The mean serum 25-hydroxy vitamin D levels of newborns and their mothers in both the case and the control groups were not significantly associated with their serum bilirubin levels. The mean of laboratory indices (calcium, phosphorus, alkaline phosphates, parathyroid hormone, and 25-hydroxy vitamin D) in mothers and newborns of the case group were nonsignificantly higher than that of the control group, but the mean vitamin D level was significantly lower among newborn cases compared with the controls (p<0.05).

Newborn vitamin D levels were significantly lower in jaundiced cases compared with those in the nonjaundiced healthy groups, which may reveal an association between indirect hyperbilirubinemia and serum vitamin D levels. We suggest that more studies should be conducted including follow-up after 15 days of age, when jaundice has typically been resolved, and before starting vitamin D supplementation.