Vitamin D: Food or Supplements?

Vitamin D promotes calcium absorption, helps to keep healthy teeth and bones, it would also play an important role in cancer prevention. All vitamins have their benefits, especially vitamins C and E, but this vitamin is part of the elites.

Unfortunately, this vitamin is relatively rare in our diet, particularly in North America. Vitamin D is mainly found in fatty fish such as salmon, trout, herring and sardines. It can also be found in dried shiitake mushrooms. In Canada, cow’s milk and fortified plant-based beverages (such as soy drinks) must be enriched with vitamin D.

This vitamin is sometimes called the “sun” vitamin. Every time your skin is exposed to sun, the cells of your skin create vitamin D. However, in Quebec, the sun is rarely at the perfect angle to allow its production. In short, from the end of fall to the beginning of spring, there is no use exposing your skin to the sun in hopes of getting your fill of vitamin D.

In the summer, 10 to 15 minutes of sun exposure produces the amount of vitamin D the body needs during the day. However, several factors come into play and can influence this theory, such as the time of day, skin colour, sunscreen or age. It is therefore better to rely on vitamin D in food instead of that which we produce.

Daily needs in vitamin D for people between the ages of 1 and 70 years old are of 600 international units (IU). To achieve this quantity with food only, you would need to drink about 6 glasses (250 ml) of skimmed milk or eat 2 portions of fish rich in vitamin D every day. It is therefore difficult to meet your needs with food only, especially in the months when the sun is not as present!

For this reason, many people could benefit from taking a vitamin D supplement, especially in winter. Even though the risk associated with consuming too much vitamin D is relatively low, we recommend speaking with your doctor before taking supplements.

Did you know?

Although vitamin D can play a role in fighting cancer, it is important to keep in mind that the sun’s rays—which produce vitamin D—are also responsible for aging of the skin and for skin cancer. The Canadian Cancer Society recommends reducing sun exposure to a maximum and applying sunscreen with SPF 15 or higher when going outdoors. If you practise outdoor sports in the summer, choose a water-resistant sunscreen with SPF 30 or higher. That way, you will be protected even if you sweat.


Canadian Cancer Society. Sunscreen. (ONLINE) (Page consulted on May 5, 2014)

Extenso. La vitamine D durant les mois d’hiver : un supplément est-il nécessaire? (ONLINE, in French only) (Page consulted on May 5, 2014)