Canadians could be forgiven for being a tad confused about the appropriate intake of the sunshine vitamin. Health Canada has one recommendation, but the Canadian Cancer Society and the Canadian Pediatric Society last year started advising people to take far more.
Health Canada says an adequate daily intake for ages one to 50 is 200 International units; for ages 51-70, 400 IU, and for over 70, 600 IU. It considers 2,000 IU the maximum safe dose. Breast-fed infants are a special category and should receive 400 IU daily, Health Canada says.
But last year, the Canadian Cancer Society advised adults with white skin to take 1,000 IU daily in fall and winter, and people with dark skin to supplement year-round at that amount, based on research linking higher doses to cancer prevention.
The Canadian Pediatric Society says pregnant women should take even more: 2,000 IU daily.
A cup of fortified milk contains 100 IU, while a typical multivitamin contains 400 or 600 IU.
Vitamin D is available over the counter in 1,000 IU pills or drops. Because vitamin D is fat soluble, a person need not take it every day, but can take a week's worth at a time, making compliance easier for those prone to forget their daily dose.
Leading international vitamin D researchers have recently issued a public letter advising the United States and Canadian governments they need to revise their recommendations to be in the range of 1,000 to 2,000 IU a day. Failure to adopt this standard “is costing thousands of lives unnecessarily each year” due to cancer, diabetes, multiple sclerosis and other diseases, it concluded.
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