One vitamin that is always in the news is vitamin D.
Vitamin D’s is most famous for helping build and maintain strong bones and teeth by balancing calcium and phosphorus levels in the blood. However, newer research suggests vitamin D also plays a role in maintaining a healthy immune system, reducing inflammation and modifying cell growth and differentiation. This suggests that vitamin D is important in the prevention and treatment of hypertension, some cancers (mainly colorectal, breast and prostate), diabetes and autoimmune disorders such as multiple sclerosis.
The question is, do we need to take supplemental vitamin D pills, or can we get enough from our diet and the sun? The body gets most of its vitamin D from UV rays hitting the skin. It is suggested that five to 30 minutes of sunshine at least twice a week is sufficient. However, when there is cloud cover, when we wear sunscreen (over SPF8) or cover our skin with clothing, this process is diminished.
Furthermore, as we age, our skin becomes less efficient at making vitamin D. Therefore, the Canadian Cancer Society recommends that all adults take supplemental vitamin D during fall and winter and all year round if you are elderly (over 70), have dark skin, don’t go outside often, or wear clothing that covers most of your skin. Breast-fed infants should also take 400 IU (international units)daily for the first year of life.
What is Health Canada’s recommended daily intake?
Infants 0-12 months: 400 IU;
Children one-18 years: 600 IU;
Adults 19-70 years: 600 IU;
Adults 71 years and older: 800 IU.
Pregnant or breastfeeding mothers: 600 IU.
Other professional organizations recommend higher doses for adults (1,000-2,000 IU); however, you should be aware you can overdose on vitamin D, and should not exceed 4,000 IU daily.
In Canada, cow’s milk is fortified with vitamin D (about 100 IU per cup); however, many dairy products, such as cheese and yogurt, are not. If you drink an alternative milk (soy, almond, rice), check the label as many are not fortified. Small amounts of vitamin D are also found in fatty fish, beef liver, egg yolks and some mushrooms.
Finally, all sources of vitamin D (food, UV, supplements) are biologically inactive and are transformed to their active form by your liver and kidneys. Unless you have end-stage liver or kidney disease, you do not need to buy “activated” vitamin D supplements.