Sun’s out. Bring it on! Not only is the sun dearly missed every winter in Canada, exposure to its UV rays stimulates the Healthy Body to produce vitamin D. But a note of caution to sun-worshippers — those same UV rays can cause skin cancer. There lies the conundrum: when we use sunscreens or cover up with clothing to reduce our risk of skin cancer, we block our skin from making vitamin D.
What is a Canuck to do? Get vitamin D from other sources, says Philippe Laroche, media relations officer at Health Canada. And protect your skin.
“Considering that the incidence of skin cancer is still rising in Canada, we recommend that the public continue to use sun protection when they go out and the UV index is equal to or higher than 3,” he says.
A Statistics Canada report released in March 2010 said 10 per cent of Canadians had vitamin D concentrations considered inadequate. Men were more likely than women to have inadequate levels of vitamin D in their blood — especially those between the ages of 20 and 39.
Not getting enough vitamin D can cause decreased levels of blood calcium and phosphorus. When the Healthy Body is short on calcium it pulls it out of the bones to keep blood levels stable, which in turn makes the bones soft or fragile and can cause osteoporosis in adults, or rickets in children. Recent medical research also suggests that besides being essential to bone health, vitamin D may help prevent cancers, autoimmune diseases, cardiovascular disease and depression.
The main source of vitamin D worldwide is exposure to sunlight, but its synthesis is affected by factors such as latitude, season, time of day, age, and skin pigmentation (people with darker skin have been found to have a lower vitamin D status).
“During the winter season,” says Laroche, “Canadians have a reduced exposure to sunlight, so it is recommended that they follow the advice in Eating Well with Canada’s Food Guide to ensure adequate vitamin D levels through diet or supplements, regardless of exposure to the sun.”
According to Health Canada, the adequate intake values for vitamin D depend on the person’s age, as follows:
Laroche says the Tolerable Upper Level of Intake, (i.e. the most we can safely take) is 2000 IU per day for anyone one year old and over. Too much vitamin D can be harmful, leading to calcification of the kidneys and other soft tissues including the heart, lungs and blood vessels.
The “sunshine vitamin” is not widely found in food, with a few exceptions. Milk is an important source of vitamin D. Canada’s Food Guide recommends that all Canadians over the age of two, including pregnant and lactating women, consume 500 mL (two cups) of milk or fortified soy beverages every day for adequate vitamin D. Vitamin D is also naturally found in egg yolks and fatty fish, and is sometime found in margarine, some yogurts and cheese, and vitamin D fortified orange juice. Otherwise, getting the recommended intake can be a challenge, especially as we age. That’s why Health Canada recommends that in addition to those two cups of milk, adults over 50 take a daily vitamin D supplement containing 400 IU (10 mcg).
A simple blood test can measure vitamin D levels in the blood. To be on the safe side, get tested, and ask your health professional what would be a suitable vitamin D supplementation for you.
Meanwhile, practice safe sunning and enjoy those rays!