Introduction: Infants are a group at risk of vitamin D (VD) deficiency. The administration of 400 IU of VD per day during the first year of life does not achieve 100% adherence. A single dose of 100,000 IU of oral VD is safe in newborns.
Objective: To compare the effect of oral administration of VD between a single dose of 100,000 IU at one month of age vs daily doses of 400 IU on serum concentrations of VD, at 6 months of age.
Subjects and method: Randomized clinical trial, without masking. 84 healthy infants were included at 1 month of age, randomized to the study group (SG) receiving a single oral dose of 100,000 IU or to the control group (CG), who received daily oral doses of VD of 400 IU from the 1st to the 6th month of life. At 6 months of life, the serum concentration of VD was determined.
Results: 65 infants completed the study, 36 in SG and 29 in CG. No VD deficiency was found. VD insufficient was 5.5% and 6.8% in the SG and CG, respectively. The serum concentration of VD at six months of age was 38.8 ± 5.2 ng/ml and 39.7 ± 6.3 ng/ml for the SG and CG, respectively (NS).
Conclusions: Supplementation of 100,000 IU of VD at one month age achieves serum concentrations of VD at 6 months of life similar to the administration of daily doses of 400 IU of VD from the 1st to the 6th month.