Oral Supplementation of Parturient Mothers with Vitamin D and Its Effect on 25OHD Status of Exclusively Breastfed Infants at 6 Months of Age: A Double-Blind Randomized Placebo Controlled Trial.

BACKGROUND: Exclusively breastfed infants are at increased risk of vitamin D deficiency and many lactating mothers have been found deficient in 25OHD stores.

OBJECTIVE: To compare serum vitamin D levels in exclusively breastfed infants at 6 months of age with or without oral supplementation of 600,000 IU of vitamin D3 to mothers in early postpartum period.

METHODS: Exclusively breastfeeding term parturient mothers were randomized 24-48 hours following delivery to receive either 600,000 IU of vitamin D3 (Cholecalciferol) over 10 days in a dose of 60,000 IU/day or placebo. 25OHD levels were measured by Radio Immuno Assay method at recruitment and after 6 months in all mothers and their infants. Urinary calcium and creatinine ratio was measured to monitor adverse effects of vitamin D3 in both mothers and infants at 14 weeks and 6 months of age. X-ray of both wrists in anteroposterior view and serum alkaline phosphatase of infants were done in both groups at 6 months of age to look for evidence of rickets.

RESULTS: Maternal profile was similar in intervention (A) and control (B) groups. Mothers' serum 25OHD levels at recruitment were also similar being 16.2 ± 9.3 ng/mL in group A and 14.1 ± 7.1 ng/mL in group B. After 6 months, 25OHD levels were 40.3 ± 21.6 and 22.9 ± 20.1 ng/mL in group A and group B mothers (p ≤ 0.00), respectively. The serum 25OHD levels in cord blood were 9.9 ± 5.7 and 8.9 ± 5.1 ng/mL, respectively, in infants born to mothers in intervention and control groups (p = 0.433). At 6 months of age, the serum 25OHD levels significantly (p < 0.00) raised to 29.1 ± 14.6 ng/mL in infants of group A compared to those of group B (15.7 ± 17.7 ng/mL). Four infants developed radiological rickets at 6 months of age, two infants each in intervention group and study group. As against 10 infants in the control group (16.94%), no infant in the study group had biochemical rickets. Urinary calcium and creatinine ratio in mothers and infants at 14 weeks and 6 months of age in both intervention and study group was within normal limits, indicating there was no adverse effects of oral administration of 600,000 IU of vitamin D3.

CONCLUSION: Serum 25OHD levels of exclusively breastfed infants significantly rise at 6 months of age when their mothers are orally supplemented with 60,000 IU of vitamin D3 daily for 10 days in the early postpartum period in comparison to infants of vitamin D3 unsupplemented mothers.