Last week I was asked to write a monthly nutrition article for one of my good friends and client for many years, Lee of WoW Power Walking. At first I was quite nervous about the idea, but then realized that this is a great opportunity for me to start walking my talk. Or at least starting on that journey. Below is the first article that I’ve submitted to her for next month’s newsletter. If anyone has suggestions for the next article or articles, please let me know. And please feel free to pass along this article to anyone you feel could use the information.What is Vitamin D? What does it do?Vitamin D is the “sunshine” vitamin, manufactured from cholesterol in the human skin when in comes in contact with UVB radiation from the sun. It regulates the body’s absorption of calcium and phosphorus making it crucially important for the maintenance of bone density, healthy bones and teeth, and the normal function of the nervous system. Without sufficient vitamin D, taking calcium supplements is useless.How do we get it?From March to early Fall, there is sufficient UVB radiation from the sun to provide adequate amounts of Vitamin D to our bodies. However, from October until March there is not enough UVB radiation reaching the Toronto area to enable our bodies to synthesize Vitamin D, so we need to consider supplementation – whether through diet or a dietary supplement.Vitamin D production is further blocked when we apply sunscreen to our bodies. According to the Linus Pauling Institute, “the application of sunscreen with an SPF factor of 8 reduces production of vitamin D by 95%.” How do we get around this? Moderate, limited sun exposure of 10-15 minutes daily – without sunscreen – during the spring, summer and fall, from 11am to 2pm, on the face and arms, will provide enough UVB radiation for the individual to synthesize sufficient vitamin D. Are there food sources available?There are few natural food sources of vitamin D, but some excellent options include shrimp, sardines, cod and eggs (from World’s Healthiest Foods). It’s also available in mushrooms and dark leafy green vegetables such as kale, collard greens, and spinach. A vast amount is also manufactured synthetically and added to bread, milk and other fortified foods.Bottom line then is even when you’re enjoying the benefits of fresh air and sunshine during your winter walks, you’re actually not able to use the sun’s energy to make vitamin D because it isn’t strong enough. From October until March (or from Halloween until March break for all you Mom’s!), supplement with a daily dose of vitamin D or make sure that you’re eating fish and greens each week. My teens enjoy their morning spritz of D-day by Biocare (a Canadian manufacturer).