Vitamin D, Calcium deficiency increase melanoma risk

Certain women at risk for developing melanoma, the most severe form of skin cancer, may cut the likelihood in half by taking vitamin D / calcium supplements.

Vitamin D and calcium are well-known for their roles in bone growth, but they also affect other cells in the body. Some studies have shown that vitamin D and calcium are associated with lower risk of colon, breast, prostate and other cancers. The researchers speculated that cancer cells lurking in the skin of women who have had a previous skin cancer may be waiting to develop into melanoma.

To determine the prevalence of vitamin D deficiency in women at the beginning of chemotherapy for breast cancer and after 1 year of vitamin D supplementation, researchers collected data on 36,282 postmenopausal women from America, 50 to 79 years old.

As part of a test to see if calcium plus vitamin D had any effect on hip fractures or colon cancer, the women were randomly assigned to take supplements or placebo. The supplements were 1,000 milligrams of calcium and 400 IU of vitamin D daily.

Over about seven years of follow-up, the women taking the supplements who previously had non-melanoma skin cancer reduced their risk of developing melanoma by 57 percent, compared with similar women not taking the supplements. The melanoma risk reduction was not seen among women who had not had an earlier non-melanoma skin cancer, the study authors noted. Overall, only 176 cases of melanoma developed.

The findings show that Vitamin D deficiency is highly prevalent in women with breast cancer.