Check Vitamin D Levels this Winter

In this newsletter I have reported that low vitamin D levels are associated with increased risk for heart attacks, strokes, at least 17 different cancers, diabetes, autoimmune diseases, depression and osteoporosis. Adequate blood levels of vitamin D are thought to be over 75nmol/L. Researchers at the University of Toronto have now shown that in the winter, more than 93 percent of the people in Toronto have concentrations below 75 nmol/L, and 75 percent have concentrations below 50 nmol/L (BMC Public Health, September 26, 2008).

Only those with light skins had average vitamin D intakes exceeding the current Recommended Adequate Intake (RAI = 200 IU/day). Those with dark skin and/or excess weight had very low levels of vitamin D. Dark skin blocks ultraviolet light. Obesity sequesters vitamin D so it is not available for use. Aging also lowers vitamin D levels as the skin of older people doesn't make vitamin D as well as during younger years.

In the wintertime, I recommend getting a blood test called D3. If it is below 75 nmol/L, you need more sunlight or vitamin D pills. The blood test for the active form of vitamin D (1,25 dihydroxy-vitamin D) is of little value as it often is normal when a person has a severe deficiency. Lack of vitamin D causes the parathryroid gland to produce massive amounts of parathyroid hormone that causes these falsely high levels. More on vitamin D