Vitamin D is important for infant bone growth, but breast-feeding infants are susceptible to vitamin D deficiency due to low levels of the vitamin in breast milk, according to background information included in the study, which was published in the May 1 issue of the Journal of the American Medical Association.
The study, by Hope Weiler and colleagues at McGill University in Montreal, included 1-month-old healthy breast-fed infants who were followed for 11 months after being randomly assigned to receive different dosages of oral vitamin D supplements. Doses were either 400, 800, 1,200 or 1,600 international units per day.
None of the dosages raised and maintained vitamin D levels within a range recommended by some pediatric societies, but all the dosages raised and maintained vitamin D levels within a lower range recommended by the Institute of Medicine, according to a journal news release.
The study did not pinpoint the ideal dose of vitamin D for infants, Dr. Steven Abrams, of Baylor College of Medicine in Houston, said in an accompanying journal editorial. He wrote, however, that clinicians could be reassured from the findings that a daily vitamin D intake of 400 international units was adequate to maintain blood levels recommended for bone health.