Vitamin D has long been known to play a role in helping the body absorb calcium, an essential part of the process for building strong bones. Now, a new study in the United States has found that vitamin D plays a role in regulating blood pressure, reducing inflammation, and controlling glucose levels, which are important factors in heart health.
Vitamin D Created by Sunlight
Writing in the February/March 2008 issue of Mother Earth News, Dr. Linda White points out that the chief source of vitamin D is sunlight. Human skin exposed to sunlight manufactures vitamin D by transforming “a derivative of cholesterol normally found in the skin into vitamin D3 (cholecaliferol).”
Humans evolved and lived near the Equator and spent most of their time outdoors wearing little clothing. As a result, they adapted to need high levels of exposure to ultraviolet B (UVB) rays to create vitamin D.
“About 50,000 years ago,” writes Dr. White, “some of our ancestors migrated toward the poles, where winter sunlight isn’t intense enough for vitamin D production.” Then along came the Industrial Revolution. Work moved indoors, out of the sun, and factories belching out smoke darkened the skies.
Vitamin D Deficiency a Global Problem
There is some debate about how much vitamin D the average human needs to be healthy. The official story is that between 200 and 600 International Units (IU) should be enough. However, the Canadian Cancer Society recommends that all Canadians get 1‚000 IU per day.
According to The Vitamin D Society, “97 percent of Canadians are vitamin D deficient at some point in the year‚ according to University of Calgary research. Worldwide‚ an estimated one billion people don’t get enough of ‘the sunshine vitamin.’ ”
With the weak levels of sunshine in Canada’s long winter, inexpensive supplements are necessary. The same rule applies for anybody living outside the tropics.
Heart Health Improved with Vitamin D
Researchers in the United States have been studying vitamin D levels and correlating them with cardiovascular disease. The research was carried out by the Heart Institute at the Intermountain Medical Center in Salt Lake City.
The AFP News Agency reports (November 16, 2009) that, “Examining 27,686 Utah patients aged 50 or older with no history of cardiovascular disease, the study found those with very low vitamin D levels were 77 percent more likely to die early than those with normal levels.”
In addition, coronary heart disease was more likely to develop in 45 percent of those with seriously low levels of vitamin D; strokes were more likely to occur in 78 percent.
Vitamin D Important in more than Bone Structure
One of the researchers is Dr. Joseph B. Muhlestein. He is quoted by Roni Caryn Rabin, in The New York Times (November 16, 2009) as saying that in his medical school days, vitamin D was seen mostly as important in dealing with rickets and calcium metabolism. It was not thought to have any other uses.
“We cardiologists didn’t worry about it; and we certainly didn’t order vitamin D levels,” Dr. Muhlestein told the Times. “What’s been discovered in the last few years is a significantly greater role for vitamin D. There are perhaps 200 different important metabolic processes that use vitamin D as a co-factor.”
Sources:
“Vitamin D: Sunshine and So Much More.” Linda B. White, M.D. Mother Earth News, February/March 2008.
“Vitamin D deficiency linked to strokes, heart disease: Study.” AFP, November 16, 2009
November 16, 2009.
“Vitamin D Shows Heart Benefits in Study.” Roni Caryn Rabin, The New York Times, November 16, 2009.
Rupert Taylor - Rupert Taylor is the editor of a magazine that provides background to current events.
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