The days are getting shorter, and for all of us living in northern latitudes, we are reminded to start taking our vitamin D supplements.
In order to get adequate vitamin D, Health Canada recommends that, in addition to getting two servings of milk or fortified beverages, everyone over the age of 50 should take a daily vitamin D supplement.
Vitamin D’s most established role is to balance calcium and phosphorus levels in the blood, helping build and maintain strong bones and teeth. However, newer research suggests vitamin D plays a role in maintaining a healthy immune system, reducing inflammation and modifying cell growth and differentiation. While the details are not all clear, vitamin D deficiencies are linked with diabetes, hypertension, some cancers, multiple sclerosis and Alzheimer’s disease. Those most at risk for deficiencies include exclusively breast-fed infants, the elderly, people with dark skin, people with fat malabsorption disorders or inflammatory bowel disease (not to be confused with irritable bowel syndrome), obese individuals and people who get little sun exposure.
How much should you take?
Health Canada recommendations are as follows: infants 400 IU, children and adults 600 IU, older adults 800 IU, pregnant and nursing mothers 600 IU.
However, other professional organizations recommend higher doses for adults (1,000 to 2,000 IU). It is important to note that there can be toxic effects from taking too much vitamin D, so Health Canada recommends that your daily dose should not exceed 4,000 IU.
What about food sources of vitamin D?
It is difficult to get adequate vitamin D from food. Fatty fish, such as salmon, is the best food source of vitamin D. In Canada, foods fortified with vitamin D including milk, milk alternatives (such as soy or almond beverages), margarine and ‘fortified’ milk products. There is also lesser amounts of vitamin D in beef liver, egg yolks, and some mushrooms.
What supplement should I take?
Most health agencies have not taken a clear stand on which supplement is best, but Osteoporosis Canada recommends vitamin D3. A concern for many purchasing supplements is to make sure what is on the label is in the bottle.
In Canada, manufacturers must follow the Natural Health Products Regulations. These include following good manufacturing practices, having site licenses, and assigning a natural health product number (look for NHN on the bottle).