Vitamin D: What you need to know

Posted: Jul 16, 2013

What does vitamin D do for my health?

Vitamin D is often called the ‘sunshine’ vitamin, as our skin is able to make the vitamin when exposed to the sun. Vitamin D is best known for its role in keeping bones and teeth healthy. Recent research suggests that vitamin D may also have benefits in fighting infections, reducing heart disease risk factors, and preventing diabetes, multiple sclerosis, and some types of cancers (especially colorectal cancer). However, more research is needed to fully understand the role of vitamin D in these conditions.

What are food sources of vitamin D?

Vitamin D is found in a limited number of foods, either occurring naturally or added to the product. Only egg yolks and fatty fish such as salmon, mackerel, sardines and tuna, naturally contain substantial amounts of vitamin D. Cow’s milk, infant formula, and margarine have added vitamin D as required by the Canadian government.
Other common food sources include yogurt and cheese made with vitamin D-fortified milk. Goat’s milk, plant-based beverages (e.g. soy beverages), and some orange juices may also have vitamin D added.
Check out the Nutrition Facts table on food labels to see if a packaged food has vitamin D. A food has a lot of vitamin D if it has at least 15% Daily Value (DV) for vitamin D per serving.

Am I at risk of being deficient in vitamin D?

Some people may not get enough vitamin D from the foods in their diet. For example, people who are lactose intolerant, and avoid dairy products, may not get enough vitamin D from their diets. Others may be at risk of deficiency because they have limited sun exposure. For example, people who mostly stay or work indoors or live in the more northerly regions of Canada, may not get enough sunlight to produce vitamin D.

Choosing vitamin D-rich foods will help you get more vitamin D.

People at risk include:

Breastfed infants who are completely or partially breastfed should receive a daily vitamin D supplement of 400 IU from birth until two years of age. Vitamin D is available as drops in many grocery stores and pharmacies. Healthy term infants fed only infant formula or who are transitioned to drinking cow milk (after 9 -12 months of age), do not require a vitamin D supplement, since vitamin D is already added to the formula and cow milk.

Adults over 50 years may not produce vitamin D in their skin as well as they did when they were younger. Health Canada recommends that adults over 50 years take a supplement of 400 IU/day.
People with skin darkly pigmented with melanin are less able to make vitamin D from being in the  sun. In addition, Aboriginal children and women of child-bearing age are at higher risk of having low vitamin D levels. For these groups of people, a vitamin D supplement may be needed if other food sources of vitamin D are not consumed.
People with  medical conditions such as Crohn's disease, cystic fibrosis, celiac disease, and some forms of liver disease, may not absorb enough of vitamin D. If you have one of these conditions, check with your doctor to ask if a vitamin D supplement is needed.

Can I take too much vitamin D?

Yes. Too much vitamin D can be harmful. The total daily intake from food and supplements combined should not exceed:

  • 1000 IU for infants 0-6 months
  • 1500 IU for infants 7-12 months
  • 2500 IU for children 1-3 years
  • 3000 IU for children 4-8 years
  • 4000 IU for children over 9 years of age and adults (including pregnant or lactating women).

The Bottom Line

Most people, except those in the risk groups noted above, can get enough vitamin D if they eat enough vitamin D rich foods, even if they protect themselves from the sun by using sunscreen and wearing a hat.
If you are concerned about your vitamin D status, speak to a health care professional such as a physician or dietitian.