UCSD Researchers State Vitamin D Needed to Cut Cancer Risk

Taking 1,000 international units (IU) of vitamin D3 daily appears to lower an individual's risk of developing certain cancers – including colon, breast, and ovarian cancer – by up to 50 percent, according to cancer prevention specialists at the Moores Cancer Center at the University of California, San Diego (UCSD) Medical Center. The researchers call for prompt public health action to increase intake of vitamin D3 as an inexpensive tool for prevention of diseases that claim millions of lives each year.

Previous studies by these researchers, including a paper in the December 2005 Journal of Steroid Biochemistry and Molecular Biology, showed the link between vitamin D deficiency and higher rates of colon cancer. The new paper, to be published on-line December 27, 2005 and printed in the February 2006 issue of The American Journal of Public Health, associates the same risks to breast and ovarian cancers, and underscores the researchers' call to action.

"For example, breast cancer will strike one in eight American women in their lifetime. Early detection using mammography reduces mortality rates by approximately 20 percent.

But use of vitamin D might prevent this cancer in the first place," said co-author Cedric F. Garland, a professor with UCSD's Moores Cancer Center and the Department of Family and Preventive Medicine at the UCSD School of Medicine.

In the paper, the authors conclude: "The high prevalence of vitamin D deficiency, combined with the discovery of increased risks of certain types of cancer in those who are deficient, suggest that vitamin D deficiency may account for several thousand premature deaths from colon, breast, ovarian and other cancers annually."

The study also found that residents of the northeastern United States, and individuals with higher skin pigmentation were at an increased risk of vitamin D deficiency. This is because solar UVB is needed for the human body to make vitamin D. The increased skin pigmentation of African-Americans reduces their ability to synthesize vitamin D.

"African-American women who develop breast cancer are more likely to die from the disease than White women of the same age," said Garland. "Survival rates are worse among African-Americans for colon, prostate and ovarian cancers as well." Even after adjustments that removed the effect of socioeconomic status and access to care, blacks were shown to have substantially poorer survival rates, a difference that the authors link with the decreased ability of blacks to make Vitamin D.

The findings are based upon an extensive systematic review of scientific papers on the relationship of blood serum levels or oral intake of vitamin D with risk of certain types of cancers published worldwide between January 1966 and December 2004. Sixty-three observational studies of vitamin D status in relation to cancer risk, including 30 of colon cancer, 13 of breast cancer, 26 of prostate cancer and seven of ovarian cancer, were assessed.