Vitamin D - Are We Getting Enough?

On June 26, 2006, the BC Dairy Foundation hosted a forum for health professionals on vitamin D. During that forum, Dr. Reinhold Vieth, an internationally recognized expert on vitamin D from the University of Toronto, discussed the need for vitamin D and its health benefits.

Vitamin D is known as the sunshine vitamin because our skin makes it when hit by UVB rays, especially at midday hours when UVB radiation is at its maximum. At the northern latitude in which we live, we cannot make vitamin D from the sun from October to March. While we assume that everyone would make vitamin D in the summer by simple sun exposure, this is not always the case. A darkskinned person needs to spend two hours in the sun to produce the same amount of vitamin D a light-skinned person makes in twenty minutes. Also, many people use sunscreen, which blocks the production of vitamin D from the skin. People who avoid the sun or are housebound do not make vitamin D. The elderly are also at increased risk for vitamin D deficiency because their skin cannot synthesize vitamin D as efficiently.

In addition to vitamin D’s well known role in bone health, recent research shows that vitamin D, at adequate levels, might help prevent 30 deaths from cancers (including colon, breast and prostate cancer) for each one caused by skin cancer. It may also reduce the risk for heart disease, Type 1 diabetes, inflammatory bowel disease and multiple sclerosis.

According to current official recommendations, set in 1997:
Infants, children, teenagers and adults up to the age of 50 need 5 μg or 200 IU of vitamin D per day. These recommendations are the same for pregnant
and lactating women.
• Adults age 51-70 years need 10 μg or 400 IU of Vitamin D per day.
• Adults age 71 or older need 15 μg or 600 IU of Vitamin D per day.
Health Canada is also recommending that all breastfed, healthy term infants in Canada receive a daily vitamin D supplement of 10 μg or 400 IU, until the infant’s diet includes at least 10 μg or 400 IU per day of vitamin D from other dietary sources or until the breastfed infant reaches one year of age.

Based on the research published since 1997, many scientists believe the recommendations for vitamin D should be significantly increased, since they are
not effective in maintaining adequate levels of vitamin D in winter, especially for people over 70.
Canadians rely mostly on milk to meet their Vitamin D needs, especially during the winter months.
Additional sources of vitamin D include cod liver oil, salmon, mackerel, tuna and margarine. People who avoid the sun and food sources of vitamin D can get their vitamin D from vitamin D supplements.
To boost your levels of vitamin D, Dr. Vieth recommends:
• Lying 10 minutes on your back and 10 minutes on your tummy twice a week
without sunscreen in the summer.
• Taking a vitamin D supplement in the winter, especially if you are over 70.
In addition, aim to:
• Drink two glasses of milk every day.
• Eat fatty fish such as salmon and sardines at least twice per week.

More about Dr. Reinhold Vieth - Dr. Vieth is a professor at the University of Toronto in the Department of Nutritional Sciences and the Department of Laboratory Medicine and
Pathobiology.