With recent studies claiming that vitamin D deficiency is leading to chronic health problems such as cancer and heart ailments, Health Canada has decided to review how much of this nutrient is needed every day by an average Canadian who doesn't get enough of it from sunshine - its most natural source.

The US Food and Nutrition Board of the Institute of Medicine in Washington will conduct the year-long review. It is on the recommendations of this board that current vitamin D intake levels have been set for the Americans and Canadians.

But since studies for this purpose were conducted only in the climatically milder US, many health institutes in this country insist that current Canadian daily levels of 200 to 600 international units of vitamin D are insufficient to ward off serious health problems. They contend that these dosage levels are good only for prevention of rickets in children.

Because of this country's cold and long winters, Canadians, particularly in its northern reaches, don't get enough of vitamin D from sunshine - which is its natural source.

Some Canadian health organisations have even claimed that the lack of vitamin D is leading to heart problems, cancer, and multiple sclerosis.

In fact, the Canadian Cancer Society and the Canadian Pediatric Society have gone to the extent of prescribing up to ten times bigger doses of vitamin D than the current standard recommended by Health Canada.