How Can Children Get Enough Vitamin D in Areas with Little Sunshine?
Scientists in Canada have determined that drinking cow’s milk and dietary supplementation are more important determinants of vitamin D levels in children than either skin color or exposure to sunlight. Deficiency of vitamin D during development can lead to a softening of the bones, a condition known as rickets. One of the most common childhood diseases, rickets can lead to skeletal deformities and a higher risk of fractures. The Recommended Daily Allowance (RDA) of a vitamin or mineral is the amount considered necessary to maintain good health. For children between the ages of 1 and 18 years, the RDA for vitamin D is 15 micrograms, or 600 International Units.
An inactive precursor to vitamin D may be synthesized in the skin on exposure to ultraviolet radiation from the sun. People living near the equator, where sunlight is strong most of the year, have no trouble producing sufficient vitamin D for their needs. At higher latitudes, however, especially during the winter months, it is not always possible to get enough vitamin D through this pathway. Instead, vitamin D must be taken in as part of the diet or in the form of a dietary supplement. This is the case in places like Scandinavia and Canada.
As part of the TARGet study (The Applied Research Group for Kids!), Dr Jonathan Maguire at St Michael’s Hospital in Ontario, Canada, studied the blood tests of 1,846 children under the age of 6. He and his colleagues discovered that vitamin D levels were higher in those children who had received dietary supplementation of vitamin D and who drank cow’s milk than those children who were reliant solely on their own synthesis of vitamin D following exposure to sunlight.
This is good news for parents in Canada, where the levels of sunlight are suboptimal for natural vitamin D biosynthesis. Factors such as dietary supplementation and provision of cow’s milk as a regular part of a child’s diet are much more easily controlled than non-modifiable factors such as skin color and the amount of ambient sunlight, particularly during the winter months.
You can read the original research paper published in JAMA Pediatrics at http://archpedi.jamanetwork.com/article.aspx?articleid=1556963