Antenatal Oral Vitamin D Supplementation and Serum 25(OH)D Concentration in Exclusively Breastfed Infants

A new study aimed to compare the proportion of exclusively breastfed (EBF) infants with severe vitamin D deficiency (25(OH)D concentration <11 ng/mL) at 6 months of age when their mothers were supplemented with 300,000 IU of vitamin D3 or a placebo during the third trimester of pregnancy.

This was a randomized, double-blinded, placebo-controlled trial, including 100 pregnant women at 30-32 weeks gestation––who intended to exclusively breastfeed for 6 months,and their infants. The women were randomized to receive either 60,000 IU of oral vitamin D3 or a placebo, weekly for 5 weeks during the third trimester. Serum 25(OH)D, calcium, phosphorus, and alkaline phosphatase concentrations were measured at recruitment, in cord blood at delivery, and in infants at 6 months. The primary outcome was proportion of infants with severe vitamin D deficiency and rickets at 6 months.

Overall, 72 mother-infant pairs were followed until 6 months. At enrollment, the mean serum 25(OH)D concentrations were comparable between the intervention and control groups. The mean 25(OH)D concentration in cord blood was significantly higher in the intervention group than in the control group. It was observed that at 6 months, infants in the intervention group had higher serum 25(OH)D levels than those in the control group. Additionally, none of the infants in the intervention group had severe vitamin D deficiency at 6 months, while the prevalence of vitamin D deficiencyin the control groupwas 54.3%. Also, no infants in the intervention group developed rickets.

From the results, it was concluded that supplementing pregnant women with vitamin D3 during the third trimester effectively prevents severe vitamin D deficiency in EBF infants at 6 months. This approach may reduce the long-term incidence of respiratory, metabolic, and neurological illnesses in these children. Maternal supplementation not only prevents vitamin D deficiency in infants but also corrects it in mothers. Nonetheless, it is essential to monitor for potential hypervitaminosis. 

Source: Prabhakar P, Faridi MM, Aggarwal A, et al. Indian Pediatrics. 2024 Jun;61(6):533-9.