People have known about the bone-building benefits of vitamin D for decades. This vitamin gives you healthier bones by helping your body absorb calcium.
Heather Chappell from the Canadian Cancer Society says that recent research suggests that vitamin D may also decrease your risks of certain cancers, particularly breast, prostate and colon cancers.
“Besides helping to prevent osteoporosis, there is strong evidence from the last five to 10 years that maintaining your levels of vitamin D actually helps to reduce cancer. We still don’t know what the optimal vitamin D levels are or how it works to prevent cancer, but the relationship is there,” she says.
Vitamin D is often called the “sunshine vitamin” because under the right conditions, the skin can produce its own vitamin D. However, during the winter, people in Alberta and the rest of Canada produce very little vitamin D in response to sunlight.
Even in the summer, people may not get enough vitamin D because of sunscreens, which block the skin from producing vitamin D. You may also not be getting enough if you don’t go outside much or wear clothing that covers most of your skin.
You are probably not getting enough vitamin D if either of the following applies to you:
- Dark skin (dark skin does not produce vitamin D as efficiently as lighter pigmented skin). Adults with dark or highly pigmented skin require 10 to 20 times more sun exposure to make the same amount of vitamin D as people with lighter pigmented skin.
- Elderly (older adults do not create vitamin D from sunlight as efficiently as younger people). In addition, older adults often limit the time they spend outdoors, which also prevents the sun exposure needed to generate vitamin D.
For these reasons, many health organizations suggest increasing your vitamin D intake through diet and/or supplements.
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Food sources of vitamin D include fortified foods, such as cow’s milk and soy or rice beverages. Margarine and fish, such as salmon and tuna, are also good sources of this vitamin.
According to Health Canada, most children and adults can meet their vitamin D needs by choosing the number of servings of milk and fortified soy beverages recommended for their age group in the Eating Well with Canada’s Food Guide.
Some groups of people need to take a supplement of vitamin D. Eating Well with Canada’s Food Guide advises people over the age of 50 to take in three servings of milk or fortified soy beverages along with a supplement of 400 IU (10 micrograms) every day.
In addition, Health Canada and the Canadian Paediatric Society both recommend that caregivers give babies who are exclusively breastfed a 400 IU (10 microgram) vitamin D supplement each day. Heather Chappell says that breast-fed babies need the supplement because breast milk doesn’t contain enough vitamin D.
Dr. Kerry Siminoski is a specialist in bone disorder and bone health at the University of Alberta. He notes that most organizations recommend that women take vitamin D supplements when pregnant and breast-feeding. “If the mother is not getting enough, then the baby isn’t getting enough,” says Dr. Siminoski.
“The idea is that the mom should get enough to protect her body and then also for the baby,” says Dr. Siminoski.
Because the benefits of vitamin D go beyond bone health, several organizations recommend different amounts of vitamin D. For example, the Canadian Cancer Society recommends that adults take daily 1,000 IU during fall and winter. Siminoski notes that vitamin D supplements can help people to meet their vitamin D needs.
“It’s very hard to get enough from what you eat. Liver is a source, but when is the last time someone told you they were eating liver for dinner? Or creamed salmon five days a week? With supplements, you ensure that you get what you need without shortchanging your other nutritional requirements or exceeding your caloric intake.”
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Despite the potential benefits, Health Canada cautions that you can get too much of a good thing. In high doses, vitamin D can be toxic. However, if you want to take between 1,000 and 2,000 IU of vitamin D a day (from food and supplements combined), you should be safe.
“There’s a huge safety margin for vitamin D as opposed to calcium,” says Dr. Siminoski.
Still, vitamin D is a fat-soluble nutrient that can build up in your body. Mild symptoms of too much vitamin D intake are nausea, vomiting, cramping and diarrhea. Severe signs of toxicity are mental confusion and changes in heart rhythm.
Wondering if you are meeting your vitamin D needs? Talk with your doctor, pharmacist or dietitian to see if you could benefit from a daily vitamin D supplement.
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Learn More
Calcium and Vitamin D for Prevention and Treatment of Osteoporosis
Capital Health (Edmonton) offers reliable information on the role of vitamin D in bone health.
Food Sources of Calcium and Vitamin D
The B.C. Health Files provide easy-to-understand information on foods that are rich in calcium and vitamin D.
Eating Well with Canada’s Food Guide: Men and Women Over the Age of 50
Find out more about the Food Guide’s recommendations for vitamin D in older adults.
Vitamin D
The Canadian Cancer Society now recommends that adults choose a daily vitamin D supplement to help reduce the risk for certain types of cancer.
