Bone Abstracts

Objective: There is no published data to demonstrate the efficacy and safety of a single bolus dose vitamin D in breastfed infants of vitamin D deficient mothers. We evaluated the efficacy and safety of this alternative approach in newborn infants <4 months of age.

Method: This single centre study was conducted from Aug 2013 to May 2014. Of 307 pregnant women diagnosed with vitamin D deficiency (25OHD<50 nmol/l) 70 were recruited. Their newborn infants were randomly assigned a daily dosing of 400 IU vitamin D for 4 months or a single dosing of 50 000 IU cholecalciferol. The primary objective was to ascertain which treatment was more effective in achieving repletion (25OHD>50 nmol/l) at 1–2 weeks and 3–4 months. The secondary objective was to determine safety using corrected calcium.

Results: Of 70 eligible infants, 36 received daily low dose and 34 received single high dose cholecalciferol. The mean vitamin D₃ in the bolus group (154 nmol/l, 95% CI 131 to 177) was significantly higher than the daily group (48 nmol/l, 95% CI 42 to 54) (P<0.001) at 1–2 weeks of age, however the reverse was seen at 3–4 months (65 nmol/l, 95% CI 59 to 71) compared to the daily group (81 nmol/l, 95% CI 77 to 85) (P<0.008). Significantly more (100%) infants in the single bolus group achieved vitamin D replete status compared to the daily group at 1–2 weeks (31%) (P<0.001). By 3–4 months, both groups achieved similar vitamin D repletion status (daily 90.9% vs bolus 88.5%) (P=0.782).

Mean corrected calcium levels in the bolus group were within the normal range at 1–2 weeks (daily 2.81 mmol/l vs bolus 2.73 mmol/l) (P=0.005) and 3–4 months (daily 2.58 mmol/l vs bolus 2.55 mmol/l) (P=0.242) despite one-third to half changing from exclusive breastfeeding to mixed and exclusive formula feeding. Clinical parameters for vitamin D deficiency between both groups were similar.

Conclusion: Single bolus dosing of 50,000IU cholecalciferol achieves higher repletion rates of vitamin D₃ at 1–2 weeks compared to daily dosing, although these were similar by 3–4 months. Single bolus dosing did not cause significant hypercalcaemia in the first 3–4 months of life.

Disclosure: The authors declared no competing interests.