The Effect of Vitamin D Prophylaxis on 25-OH Vitamin D Levels in Children

Vitamin D deficiency is a major public health problem. The aim of our study was to determine serum 25-hydroxyvitamin D levels among healthy children aged 3-36 months in a setting where vitamin D prophylaxis is a national policy for infants during the first year of life and among pregnant women.

A total of 190 healthy children with a mean age of 15.9 ± 10.4 months were prospectively enrolled.

The mean 25-hydroxyvitamin D level of children was 38.1 ± 16.2 ng/mL. 25 Hydroxyvitamin D level was ≥20 ng/mL in 87.4% of children while it was between 12 and 19 ng/mL in 10.5% and <12 ng/mL in 2.1% of the children. Children who were on vitamin D prophylaxis were found to have significantly higher 25-hydroxyvitamin D levels than those who were not on prophylaxis (41.6 ± 17.6 vs 33.6 ± 13.1 ng/mL; P = .001). None of the children >1 year of age who were on prophylaxis had 25 hydroxyvitamin D levels <20 ng/mL. No significant difference in 25-hydroxyvitamin D levels was found between children who were receiving different vitamin D doses (400 IU vs >400 IU). Analysis of covariance revealed that vitamin D prophylaxis and vitamin D supplementation of the mother during lactation had significant effects on 25-hydroxyvitamin D levels (P = .034 and P = .009, respectively).

Although vitamin D prophylaxis at a dose of 400 IU seems to be sufficient to prevent vitamin D deficiency, we suggest that continuing vitamin D supplementation beyond 1 year of age with supplementation of pregnant and especially lactating mothers could have an impact on a replete vitamin D status among infants.