Winter's coming, so how much vitamin D do we need? How much time do you have to spend in the sunlight to obtain adequate amounts? How does obesity affect the dosage? How many diseases can be prevented by adequate amounts of this vitamin? And what can a psychologist tell us about this vital vitamin?
Years ago I reported that Dr. Catharine Gordon, a professor of pediatrics at The Harvard Medical School, tested the vitamin D levels of teenagers from 11 to 18 years of age. She found that 14 per cent of these adolescents were in deficient in vitamin D. Today about 30 per cent of adults are low in D.
Dr. Glenn Braunstein, professor of medicine at the University of California, said her research was a wake-up call. It showed it not only the housebound, or the elderly in nursing homes, that are getting insufficient sunlight.
In the 19th century, large numbers of children suffered from rickets due to a lack of sunlight. To solve this problem, children with rickets were taken for long voyages on what they called "Boston's Floating Hospital" to expose them to the health benefits of sunshine.
Today we know that adequate amounts of vitamin D are needed in the bowel to absorb the calcium and keep the bones strong. Vitamin D also acts on the bone cells to release the calcium and maintain normal blood levels of this important mineral.
Can a lack of vitamin D protect against infection? You would expect to get this answer from an infectious disease expert, not a psychotherapist. But Dr. John Campbell, a U.S. Psychologist, noted that when the 2005 flu epidemic struck the Hospital for the Criminally Insane, the infection spared those patients who were taking vitamin D!
Another researcher, Dr. Mitsuyoshi Urasima, professor of epidemiology, in Japan, reports in the American Journal of Nutrition, that patients given 1,200 IU of D were less likely to develop influenza than those not receiving it.
Dr. John Ann Manson, a professor of medicine at The Harvard Medical School, reports strong evidence that high blood levels of vitamin D protect against colon cancer.
To get still another opinion I interviewed Dr. Andrew Saul, editor-in-chief of the Orthomolecular News Service, a world authority on vitamins. Saul says that colon cancer is clearly associated with vitamin D deficiency. He adds that inadequate vitamin D levels are also associated with ovarian cancer. And that research by the National Library of Medicine reveals there are 300 papers on how vitamin D helps to fight prostate and breast cancer.
Dr. Michael Holick, at Boston University, an authority on vitamin D, believes that vitamin D's greatest strength is its role in fighting cancer. He says studies show that people living in higher latitudes who have less sun exposure have a risk of dying from almost all types of cancer, especially breast, colon, prostate and skin cancer.