Winnipeg, MB — January 6, 2005 – With winter upon us in Canada, it is important to take note of the many benefits of Vitamin D.  Most Canadians are a risk for vitamin D deficiency because of our lack of sun exposure, particularly during the winter months.

We obtain Vitamin D, sometimes known as the sunshine vitamin, through our diet or by exposure to sunlight.  When sunlight reaches our skin, it creates a reaction producing Vitamin D3, which the liver and kidneys convert into biologically active metabolites.  Canada’s long, dark winters can mean that very little Vitamin D is being formed in the skin for several months of the year.  The fact that there are very few foods containing Vitamin D can further complicate the matter. 

A lack of vitamin D can have far reaching effects on the body. Vitamin D increases calcium absorption by as much as 30 to 80 percent 1, which means that Vitamin D deficient individuals are at greater risk for bone loss and even fractures. 

Bone loss is not the only result of Vitamin D deficiency.  Many recent studies from around the world are revealing that the sunshine vitamin’s role in health is far more complex.  Some studies are showing that Vitamin D supplementation can provide some protection against deadly diseases including multiple sclerosis (MS), diabetes and even cancer.

Based on the multitude of research that supports Vitamin D supplementation and the many diseases it can help prevent, noted Canadian researcher, Dr. Reinhold Vieth, argues that current Vitamin D recommendations are woefully inadequate.  According to Dr. Vieth, the minimal daily requirement of Vitamin D should be in the range of 4,000 IU from all sources, rather than the 200 IU currently suggested.

Bone Loss, Osteoporosis and Muscle Strength
Prolonged deficiency of Vitamin D can increase the risk of bone loss at an earlier age.  Doctors are now diagnosing women in their 40s with Osteoporosis.  Based on this disturbing trend, The Osteoporosis Society of Canada recommends higher intakes of calcium and vitamin D (calcium 1500mg/day and vitamin D 800 IU/day. They strongly purport the use of Vitamin D because it is essential for optimal calcium absorption and thus is important for bone health. 

Multiple Sclerosis
There is scientific evidence indicating that Vitamin D deficiency is associated with MS onset and progression.  The evidence includes high prevalence rates of MS closely tracking in areas of low intake of Vitamin D.  Animal experiments reveal that Vitamin D hormone can suppress a variety of animal autoimmune diseases included EAE, the animal equivalent of MS.2  The researchers believe that Vitamin D can have a suppressant effect on autoimmune reactions and help to slow autoimmune disease. 3

The Harvard School of Public Health in Boston recently presented human evidence showing the protective effect of Vitamin D against MS. The January 2004 edition of Neurology, reported on two on-going studies of 187,500 U.S. nurses, women getting at least 400IU of Vitamin D per day, who are showing only 60 percent the risk of developing MS compared with women getting less of the vitamin. 4

Cancer
Like MS, several Cancers (not skin cancer) become less common in populations that reside closer to the equator.  In the July 2003 Journal of Nutrition, JoEllen Welsh of the University of Notre Dame and her colleagues reviewed laboratory evidence that vitamin D signals colon, breast and prostate cells to differentiate into mature forms, stop growing, and eventually succumb to programmed cell death. “We’ve shown that if you give [a chemical analog of 1,25D] to an animal that has a mammary tumor, that tumor will regress.” Other researchers, she notes, have used 1,25D analogs to inhibit the spread of cancer or the growth of blood vessels that feed new tumors in laboratory animals. 5

1) Osteoporosis Society of Canada, Vitamin D: A Key Factor in Good Calcium Absorption. (www.osteoporosis.ca)

2) Lemire, J. and Adams, J., 1992, 1,25-dihydroxyvitamin D3 prevents the in vivo induction of murine experimental autoimmune encephalomyelitis. J. Clin.Invest., v.87, p. 1103-1107

3) Vitamin D Supplementation in the Fight Against Multiple Sclerosis, Ashton, F. Embry.  Pages 1-12

4) Harvard School of Public Health: High Intake of Vitamin D Linked to Reduced Risk of Multiple Sclerosis, Press Release January 12, 2004; http://www.hsph.harvard.edu/press/releases/press01122004a.html

5) Welsh, J., et al. 2003. Vitamin D3 receptor as a target for breast cancer prevention. Journal of Nutrition 133(July):2425S-2433S.