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IMAGE SOURCE: Wikimedia Commons/ Portugal sunbather/ author: Pedro Simoes
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For years Americans have been told to stay out of the sun because of the risk of skin cancer.
But vitamin D, made by the skin in the presence of the sun, is making a comeback as a number of studies are reporting that vitamin D may reduce the risk and spread of breast cancer.
A new study to be presented at the end of the month before the American Society of Clinical Oncology (ASCO) finds women with vitamin D deficiency were more likely to have a recurrence of breast cancer or to die from the disease.
Only 24 percent of the patients in the study had adequate levels of vitamin D when they were diagnosed and these women were linked to poorer outcomes.
Of the 512 newly diagnosed women followed between 1989 and 1995, 37.5 percent were deficient in vitamin D and younger women who didn’t supplement had among the lowest levels of the nutrient.
The risk of breast cancer metastasizing was almost double in women with deficient levels of vitamin D at diagnosis and the risk of dying was 75 percent higher in women with low levels.
Last May, researchers from Brigham and Women’s Hospital and Harvard Medical School found that those women with a higher intake of calcium and vitamin D through food sources and supplements had a lower risk of breast cancer.
More aggressive tumors that tend to spread seemed most affected by the nutrients. And older women did not show the same benefits, but that may be due to the fact that they may need higher levels of the nutrients than were measured in the study.
Study author, American Cancer Society (ACS) nutritional epidemiologist Marji McCullough, ScD, RD, tells Web MD that more study is needed to determine how vitamin D and calcium works on the breast cancer risk for older and younger women.
Vitamin D and calcium are the two nutrients are already recommended to fight the effects of thinning bones from osteoporosis in older women.
Last March, an article in the Toronto Globe and Mail told the story of how a pair of epidemiologist brothers in 1974 found that higher rates of colon cancer were found in the northern states with presumably less sunshine exposure.
The Vitamin D Council, a group of citizens promoting research and education about vitamin D, reports vitamin D is a steroid hormone precursor. A deficiency may play a role in causing 17 varieties of cancers, the group reports, as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, and periodontal disease.
While current dietary recommendation for vitamin D are 200 IU a day, with more for older women. Experts say look at a range between 1,000 to 1500 IU a day.
One vitamin D researcher takes 2,000 IU per day.
There is controversy about whether too much vitamin D can be toxic. The Vitamin D Council says that is a myth, unless you take more than 400,000 IU a day.
Look to salmon and tuna as sources for vitamin D and sun exposure helps your body synthesize vitamin D naturally.
On a sunny day you can absorb between 2,000 and 5,000 IU of vitamin D without sunscreen in 15 minutes. About 40 percent of the body should be exposed for maximum absorption.
Should you worry about skin cancer? The study authors recommend you mix your vitamin D consumption between sun exposure and diet.
The American Cancer Society and the National Council on Skin Cancer Prevention met last year to discuss the controversy about the benefits and downsides of sun exposure.
The news for the sun was good. Weighing the risks with the benefits, there is a growing body of evidence linking vitamin D to a decrease in bone fractures in the elderly and in a protection from some cancers.
The group recommends that small amounts of sun exposure are the preferred method of obtaining vitamin D limiting it to about 10 minutes a day without sunscreen.
McCullough tells WebMD that it’s a question of balance, don’t overdo it.
"We need to make sure that people don't interpret this as meaning that going to the beach and sunbathing for hours without sunscreen is a good idea," she says.
The study was published in last Mays issue of the Archives of Internal Medicine. #