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WINTER HEALTH
Dietitian Advice on
Vitamin D
TOUTED AS A PANACEA FOR MOST CHRONIC DISEASES: DIABETES, OSTEOPOROSIS, MULTIPLE SCLEROSIS, CANCER, AUTOIMMUNE DISEASES, INFLUENZA, COLDS AND CARDIOVASCULAR DISEASE, DOES VITAMIN D DELIVER?
FACT: Canadians don’t get enough vitamin D in winter
By Doug Cook, RD, MHSc It seems you can’t turn on the TV or open the newspaper without being hit with another story about the wonders of vitamin D. It has essentially been touted as a panacea for most of the chronic diseases that afflict humanity: diabetes, osteoporosis, multiple sclerosis, breast, colon, breast and prostate cancer, autoimmune diseases, influenza, colds and North America’s number one killer, cardiovascular disease. While there is a lot of information available; there is also some confusion as well.
WILL THE REAL VITAMIN D PLEASE STAND UP For the purpose of general nutrition, the term vitamin D is used to refer to either D2 (ergocalciferol) or D3 (cholecalciferol). D3 is what’s produced by the skin upon exposure to sunlight (adequate UVB), found in some foods (mostly fatty fish), and in supplements. D2 is the vegetarian version (mainly from mushrooms) and it’s widely accepted to be less potent than D3. D2 is used to fortify non-dairy beverages like soy, almond and rice. Vitamin D is not a vitamin; it was misclassified as a vitamin when it was discovered in 1922. It is a pro-hormone. Almost all cells and tissues throughout the body are capable of converting vitamin D into its active hormone form. There are 2700 vitamin D binding 12 Healthy Directions December/January 2012
sites, on our DNA, near genes that are involved in nearly every known chronic disease. It is because of this that vitamin D has such a wide, positive impact, on overall health.
DOES SPENDING TIME OUTDOORS IN WINTER HELP WITH GETTING ENOUGH D? The primary source of vitamin D is the sun. There are a couple of caveats. Only UVB can produce it. Anything that blocks UVB will block vitamin D production, this includes windows, smog, clothing, sunscreen, complexion and age (older adults are not as efficient at producing it). In Canada, due to a lack of UVB from the beginning of October to the middle of April, we cannot make any vitamin D from the sun; however, most of us don’t have the chance to make enough until June when we can wear shorts and a t-shirt.
WHAT IS THE IDEAL BLOOD LEVEL AND DOSE? Experts suggest that the answer to ‘how much vitamin D should I take’ is this: what ever it takes to raise your blood level to optimize health. Great debate rages over what the ideal blood level of vitamin D should be but some basic facts point the way. Using bone health