Optimal Vitamin D Dosage for Infants Remains Uncertain
Study offers comparison of effect of different vitamin D supplementation dosages in breastfed infants
TUESDAY, April 30 (HealthDay News) -- Supplementing healthy, term, breastfed newborns with 1,600 international units (IU) of vitamin D daily raises plasma levels to the higher target level recommended by some pediatric societies after three months, while lower dosages can raise plasma levels to the lower target level recommended by the Institute of Medicine, according to a study published in the May 1 issue of the Journal of the American Medical Association, a theme issue on child health.
Sina Gallo, R.D., M.Sc., from McGill University in Montreal, and colleagues randomly assigned 132 healthy, term, breastfed 1-month-old infants to 400; 800; 1,200; or 1,600 IU/day oral cholecalciferol (vitamin D3) supplements and measured subsequent plasma 25-hydroxyvitamin D (25[OH]D) concentrations up to 12 months later.
After three months, the researchers found a dose-dependent relationship between dosage and 25(OH)D concentration, with only 55 percent of infants receiving 400 IU/day having 25(OH)D concentrations of at least 75 nmol/L compared with 100 percent of infants receiving 1,600 IU/day. However, at 12 months, 97.5 percent of infants in all groups did not sustain this concentration. The 1,600 IU/day dosage was discontinued prematurely due to elevated plasma 25(OH)D concentrations associated with hypercalcemia. All four groups attained 25(OH)D concentrations of at least 50 nmol/L in 98 percent of infants at 12 months. Dosage was not associated with growth and bone mineral content.
"Among healthy, term, breastfed infants, only a vitamin D supplement dosage of 1,600 IU/d (but not dosages of 400, 800, or 1,200 IU/d) increased plasma 25(OH)D concentration to 75 nmol/L or greater in 97.5 percent of infants at three months," Gallo and colleagues conclude. "However, this dosage increased 25(OH)D concentrations to levels that have been associated with hypercalcemia."
One author disclosed financial ties to pharmaceutical companies.