Randomized Controlled Trial of Various Doses of Supplemental Vitamin D in Infancy

The current recommended dose of supplemental vitamin D for infants — 400 IU/day — is enough to prevent rickets, but few studies have examined the ideal dose necessary to achieve other bone and nonbone health outcomes or to maintain adequate plasma 25-hydroxyvitamin D (25[OH]D) levels in infants (recommended as ≥75 nmol/L [30 ng/mL] by the Endocrine Society and ≥50 nmol/L [20 ng/mL] by the Institute of Medicine). To examine the effects of a range of doses on vitamin D status, researchers in Canada randomized 132 healthy, term, 1-month-old breast-fed singleton infants (mostly white) to receive daily vitamin D doses of 400, 800, 1200, or 1600 IU until age 12 months. Most infants were receiving vitamin D supplementation at baseline. The primary…