The American Academy of Pediatrics (AAP) has doubled the amount of vitamin D recommended for infants, children and adolescents, from 200 IU to 400 IU starting in the first few days of life.

The previous recommendation, issued in 2003, was amended following a review of new clinical trials on vitamin D and evidence suggesting the safety of giving 400 IU per day to the pediatric population.

Clinical data indicates that 400 units of vitamin D a day will prevent and treat rickets, a bone-weakening disease. Adequate vitamin D throughout childhood may also reduce the risk of osteoporosis.

Vitamin D is essential for promoting calcium absorption in the gut and maintaining adequate serum calcium and phosphate concentrations to enable normal mineralization of bone. It plays other roles in human health as well, including modulation of neuromuscular and immune function and reduction of inflammation. Dietary sources of vitamin D are limited, however, and it is difficult to determine a safe amount of sunlight exposure for the body to synthesize vitamin D.

The new clinical report, titled “Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents,” is expected to be published in the journal Pediatrics.

The new recommendations include:

•    Breastfed and partially breastfed infants should be supplemented with 400 IU a day of vitamin D beginning in the first few days of life.
•    All non-breastfed infants, as well as older children, who are consuming less than one quart per day of vitamin D-fortified formula or milk, should receive a vitamin D supplement of 400 IU a day.
•    Adolescents who do not obtain 400 IU of vitamin D per day through foods should receive a supplement containing that amount.
•    Children with increased risk of vitamin D deficiency, such as those taking certain medications, may need higher doses of vitamin D, but this should only be done in consultation with a health-care professional.

Given the growing evidence that adequate vitamin D status during pregnancy is important for fetal development, the AAP also recommends that providers who care for pregnant women consider measuring vitamin D levels in this population.