Breast cancer patients with high levels of vitamin D in their blood are twice as likely to survive the disease as women with low levels of this nutrient, report University of California, San Diego School of Medicine researchers in the March issue of Anticancer Research.
In previous studies, Cedric F. Garland, DrPH, professor in the Department of Family and Preventive Medicine, showed that low vitamin D levels were linked to a high risk of premenopausal breast cancer. That finding, he said, prompted him to question the relationship between 25-hydroxyvitamin D—a metabolite produced by the body from the ingestion of vitamin D—and breast cancer survival rates.
Garland and colleagues performed a statistical analysis of five studies of 25-hydroxyvitamin D obtained at the time of patient diagnosis and their follow-up for an average of nine years. Combined, the studies included 4,443 breast cancer patients.
“Vitamin D metabolites increase communication between cells by switching on a protein that blocks aggressive cell division,” said Garland. “As long as vitamin D receptors are present tumor growth is prevented and kept from expanding its blood supply. Vitamin D receptors are not lost until a tumor is very advanced. This is the reason for better survival in patients whose vitamin D blood levels are high.”