Is vitamin D more than a feeling?

Health Canada says it will launch a study by this fall investigating dramatic claims that a lack of vitamin D could be linked to ailments such as cancer, heart disease and multiple sclerosis.

There has been rising pressure on Health Canada for such an investigation because the Canadian Cancer Society and the Canadian Pediatric Society say the evidence on the benefits of taking more of the sunshine vitamin is so strong that they are recommending large doses of it – amounts that, for some ages, are five to 10 times higher than what the government advises.

Major disagreements among respected public-health agencies about the required amount of an everyday vitamin are almost unheard of in the medical community, and Health Canada, in response to questions from The Globe and Mail, said it intends to sign a contract by this fall for a study on vitamin D health claims and dosage.

The vitamin review will be conducted by the Institute of Medicine's Food and Nutrition Board, a respected Washington-based science advisory group.

Many researchers view Canada's current standard as seriously outdated because it was developed in 1997, and was based mainly on the low levels of vitamin D needed to prevent childhood rickets.

A dose review is “very urgent because I've seen remarkable things happen in my practice” using vitamin D treatments, said Gerry Schwalfenberg, a clinical lecturer in the department of family medicine at the University of Alberta in Edmonton. He has found that the nutrient helps with diabetes and chronic back pain at doses higher than what Health Canada recommends.

Canada's current recommended doses range from 200 to 600 international units a day, depending on age.