Vitamin D-3 For Cancer Treatment & Prevention

Probably most famous for assisting with calcium absorption and supporting bone health, vitamin D also shows promise in the area of cancer treatment and prevention. Recent studies suggest that deficiency of this vitamin, which acts in the body like a steroid hormone, may contribute to several types of cancer, including colon, breast and prostate. Of the two forms of vitamin D most important to humans -- D-2 and D-3 -- D3 has better absorption. Consult your doctor about whether supplementation could assist with your cancer treatment or prevention regimen.

Sources of Vitamin D-3

Few good food sources of vitamin D exist, making deficiency common, especially among vegetarians. Cod liver oil, salmon and sardines are among the foods rich in vitamin D-3. The most reliable source of vitamin D-3 is direct contact of the skin with sunlight. In 2003, Dr. Michael Holick of Boston University School of Medicine reported in "Mayo Clinic Proceedings" that just five to 15 minutes of direct sunlight a day could provide adequate vitamin D intake for most people. However, dark-skinned people, those who live in northern climates and people using sunscreen may not get adequate intake from the sun and may require supplementation to get the recommended dietary allowance of 600 IU for ages 1 to 70.

Colon Cancer

Researchers have discovered that different types of malignant tumors contain vitamin D receptors, leading to the theory that a vitamin D deficiency may contribute to some cancers. Researchers from the Naval Health Research Center in San Diego published the results of their study of vitamin D and colon cancer in the "Journal of Steroid Biochemistry and Molecular Biology" in 2005. In their investigation, they found a link between colorectal cancer risk and vitamin D deficiency, either from inadequate exposure to the sun or low dietary intake. They concluded that daily intake of 1,000 IU of vitamin D reduced this risk by 50 percent.

Breast Cancer

Vitamin D deficiency also appears to affect breast cancer risk. A study by a Harvard School of Public Health team followed more than 88,000 women for 16 years and found that high intakes of vitamin D reduced breast cancer risk in premenopausal women. Results appeared in the "Journal of the National Cancer Institute" in 2002. In a pooled analysis published in 2007 in the "Journal of Steroid Biochemistry and Molecular Biology," researchers concluded that 2,000 IU of vitamin D-3 daily and moderate exposure to sun cut breast cancer risk by 50 percent.

Prostate Cancer

Researchers began linking prostate cancer to vitamin D deficiency in the early 1990s. Then, a 2003 study of men in Nordic countries uncovered a connection between prostate cancer and both low vitamin D and high vitamin D intake. Reporting in the "International Journal of Cancer" on their in vitro testing of 200,000 blood serum samples, researchers showed that vitamin D does inhibit cancer cell growth, but in very high doses can create a resistance in the body that can increase prostate cancer risk. According to the Office of Dietary Supplements, sun exposure will not create too much vitamin D-3 in the body, but oversupplementation can. The federal Food and Nutrition Board has set the tolerable upper intake level for vitamin D at 4,000 IU per day. Consult your doctor about the use of vitamin D supplements for prostate cancer.