Vitamin D May Lower Some Cancer Risk
Benefits Seen for Breast, Colon, and Ovarian Cancer
Dec. 28, 2005 - There is growing evidence that vitamin D helps protect against colorectal cancer, and now a group of researchers who have long studied the vitamin say the same is true for breast cancer and ovarian cancer.
In a new analysis, the researchers contend that taking 1,000 international units (IU) of vitamin D daily can cut colon, breast, and ovarian cancer risk.
The researchers urged public health officials to increase recommendations for vitamin D consumption, calling the vitamin an inexpensive tool for preventing cancers that claim millions of lives each year.
The easiest way for the body to get vitamin D is through sun exposure, because UV rays from the sun trigger the natural synthesis of the vitamin in the body. But the researchers did not address sun exposure in their analysis, focusing instead on the message that people need to get more vitamin D through the foods they eat and vitamin supplements.
Vitamin D Recommendations
Current recommendations call for people between the ages of 1 and 50 to consume 200 IU of vitamin D daily, with 400 IU recommended for those between the ages of 51 and 70. After age 70, 600 IU of vitamin D are recommended each day.
"The cost of a daily (1,000 IU) dose of vitamin D3 is less than 5 cents, which could be balanced against the high human and economic costs of treating cancer attributable to insufficiency of vitamin D," the researchers write in the February 2006 issue of the American Journal of Public Health.
Researcher Cedric Garland, DrPH, of the University of California, San Diego, has been studying the impact of vitamin D on cancer since the 1980s. He says the evidence now suggests that vitamin D deficiency is responsible for several thousand premature deaths each year from colon, breast, and ovarian cancer.
"There have now been more than 1,000 studies examining vitamin D and cancer," he tells WebMD. "It has been a slow process, but I do believe that health officials are beginning to embrace our message."
Intriguing, but Not Conclusive
In their latest analysis, Garland and colleagues conducted a comprehensive review of observational studies evaluating vitamin D status in relation to cancer risk. The analysis involved 63 studies conducted between 1966 and 2004, and many examined sun exposure as a measure of vitamin D levels.