Vitamin D halves breast cancer risk in premenopausal women

By David Liu Ph.D.
December 12, 2008

(foodconsumer.org) — A new study published in the Jan 2009 issue of International Journal of Cancer found that premenopausal women who had higher levels of serum 25-hydroxyvitamin D or 25(OH)D were significantly less likely to develop breast cancer.

Laboratory and epidemiological studies have already linked vitamin D to breast cancer prevention although vitamin D levels considered in the studies mostly came from diet.

The current population-based case-control study involving 289 cases and 595 matched controls examined the association between plasma 25(OH)D and breast cancer risk.

Abbas S and colleagues from German Cancer Research Center in Heidelberg, Germany found that compared to premenopausal women who had only less than 30 nmol/L vitamin D, women who had 30-45, 45-60, >/=60 nmol/L were at a 32, 41 and 55 percent reduced risk of breast cancer respectively.

One interesting finding is that the protective effect was in a non-linear relationship with the plasma vitamin D level and there seemed to be a threshold at about 50 nmol/L.

Dr. John Cannell, a vitamin D expert and founder of Vitamin D Council, a non-profit-educational organization, suggested that only high serum levels of vitamin D result in an anticancer effect.

From the current study, Abbas and colleagues also found the protective effect was stronger on progesterone receptor negative tumors.

They concluded that “Our findings support a protective effect of vitamin D for premenopausal breast cancer.”