Vitamin D: A look at the research behind the recommendations
Ah, spring is in the air. For me, spring brings to mind flowers, sunshine and vitamin D! In a recent article on healthychildren.org, the American Academy of Pediatrics discuss the recommendation that all breastfed infants be supplemented with 400IU of vitamin D per day. They extend this recommendation to non-breastfed babies consuming less than 32 ounces (1,000 mL) of vitamin D-fortified infant formula as well. Canada has been recommending 400IU of vitamin D per day for the breastfed baby since 1967. The Canadian Paediatric Society (CPS) also recommend a daily dose of 400IU of vitamin D during April-October for formula-fed babies in northern communities. While the idea of providing breastfed infants with vitamin D supplements is not new, newer findings on vitamin D are important to recognize and share with the parents that we work with.
Vitamin D supplementation is about more than preventing rickets
Rickets, a disease that results in abnormal bone growth, can occur when the body is deficient of vitamin D, calcium and phosphorus (an in-depth review of vitamin D deficiency can be found here). Despite vitamin D fortification of certain food items and public awareness strategies, rickets is still a problem in North America, especially in northern latitudes. The Canadian Paediatric Surveillance Program reported 104 confirmed cases of rickets between 2002 and 2004 and there were 228 reported cases in the United States between 1986-2006.
Although the current prevalence of rickets is concerning, vitamin D supplementation is about more than preventing rickets. More recent evidence has suggested that vitamin D deficiency has also been linked to an increased lifetime risk of osteoporosis; asthma; autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and inflammatory bowel diseases; diabetes; disturbed muscle function; resistance to tuberculosis; and the pathogenesis of specific types of cancer (reviewed by the CPS). It has been estimated that in the United States alone, vitamin D deficiency carries an economic burden of $40 billion to $53 billion dollars per year, an amount that includes only the burden of disease from rickets and osteomalacia, associated deformities, bone fractures, muscle weakness, and pneumonia, as well as multiple sclerosis and common cancers associated epidemiologically with vitamin D deficiency such as prostate, colon, and breast cancers. It has also been estimated that somewhere between 50,000 to 70,000 people in the United States will die prematurely each year as a result of cancer related to insufficient vitamin D. It is clear that vitamin D sufficency has both short term and lifelong benefits.
Supplements are the main source of Vitamin D for young infants
Assuming a mother is vitamin-D sufficient, and assuming a breastfed infant is consuming an average of 750mL of breastmilk per day, the amount of vitamin D the baby is receiving from the breastmilk is approximately 11-38 IU per day. This amount can be even less if mother is vitamin-D deficient due to factors such as clothing choice, skin color, diet, and geographical location. The amount of vitamin D currently recommended for breastfed infants is 400 IU per day. Clearly another source of vitamin D is needed for these infants. Although exposure to sunshine can increase vitamin D levels, direct sun exposure is not recommended for infants under 6 months of age. Therefore, the best option for infants that are exclusively breastfeed without adequate sun exposure is a vitamin D supplement of 400 IU per day.
Although vitamin D deficiency is not as commonly diagnosed in formula-fed infants due to the fortification of infant formula, it is still possible for these infants to suffer from vitamin D deficiency. In a 2006 prospective study from the UK, 50% of the children aged 0 to 5 presenting with rickets were formula-fed. It is therefore important to determine the daily intake of vitamin D in formula-fed infants based on the amount of formula consumed and the vitamin D content of the formula. It is for this reason that the AAP recommends all non-breastfed infants who are consuming less than 32 ounces (1 litre) per day of vitamin D-fortified formula receive a vitamin D supplement of 400 IU a day. In addition, the CPS advises families in northern communities to supplement formula-fed infants with 400IU of vitamin D per day during the months of October to April, even if they are drinking 32 ounces (1 litre) of formula daily.
More Information for Parents
There are many great information sources for consumers. Here are a few sources of online information that you may wish to share with the parents you work with:
Vitamin D Quick Facts from the National Institutes of Health
Vitamin D summary for parents from the CPS
A parent-friendly video from the Vancouver Island Health Authority in British Columbia, Canada.