According to a newly released 4-year study, large doses of vitamin D may reduce cancer risk. In the study comprised of approximately 1,200 women over the age of 55, those supplementing with 1,100 IU's of vitamin D experienced a 60 percent lower incidence of all cancers. In evaluating cancer incidence for the final 3 years of the study only (skipping the first year of the study to eliminate the possibility of pre-existing cancers), vitamin D supplementation lowered the incidence of cancers by 77 percent. The researchers initially were studying the bone health in post-menopausal women until they discovered vitamin D's cancer reducing benefits. More studies are needed to see if the findings also hold true for men as well as cancer reduction in the younger adult population. Vitamin D is made by the body after sunlight exposure and can be consumed through the diet with the consumption of fatty fish and fortified milk. Thus, it is recommended that most supplement with vitamin D rather than rely on dietary vitamin D and/or the harmful effect of sun exposure.
Source: American Journal of Clinical Nutrition, Vol. 85, No. 6, 1586-1591, June 2007.