Vitamin D plays many important roles in our overall health. It supports the growth and maintenance of healthy bones and teeth, and it is essential to the absorption of calcium and phosphorus, two minerals that we need for to stay healthy.
Normally, our body makes 80 to 90% of the vitamin D we need, using a reaction between our skin and the rays of the sun. However, because of our geographic location in Canada, the rays of the sun are too weak in the winter to trigger the reaction that leads to the creation of vitamin D. In addition, since there is very little vitamin D in the foods we eat, it’s almost impossible to meet our vitamin D needs through our diet alone.
For all these reasons, Canadians are more likely to develop a vitamin D deficiency between the months of October and April. The risk of deficiency is even greater among individuals who get very little sun exposure throughout the year, among older individuals (their skin has lost some of its ability to make vitamin D), and among people with certain diseases that affect the absorption of vitamins and minerals (e.g. celiac disease, cystic fibrosis, chronic liver disease, inflammatory bowel disease).
Health Canada and Osteoporosis Canada therefore recommend that we take a vitamin D supplement every day during the winter (or throughout the year in individuals at greater risk of a deficiency). The recommended dose depends on certain criteria. For example, healthy adults under the age of 50 should take 400 to 1,000 IU per day, whereas people above the age of 50, at high risk of a deficiency, or suffering from osteoporosis should take 800 to 2,000 IU per day.
Don’t hesitate to consult your pharmacist if you have any questions on your vitamin D needs.