A recent study has found a lower risk of breast cancer over five years of follow-up in association with higher levels of serum vitamin D or vitamin D supplementation.*
The investigation included participants in the Sister Study, which enrolled women who had a sister diagnosed with breast cancer, which placed all these women at higher breast cancer risk.
The study evaluated 1,611 women who subsequently developed breast cancer and compared them with 1,775 randomly selected women free of breast cancer. Blood levels of 25-hydroxyvitamin D were analyzed in both groups.
A serum 25-hydroxyvitamin D level of at least 38 ng/mL was associated with a 21% lower adjusted risk of developing breast cancer over follow-up in comparison with levels of 24.6 ng/mL or less.
The use of a vitamin D supplement at least four times per week was associated with an 11% lower risk of the disease, in comparison with those who did not regularly supplement. Breast cancer risk was 17% lower among postmenopausal women who supplemented with modest doses of vitamin D.
Editor’s Note: “Our results support the hypothesis that vitamin D supplementation could be effective for breast cancer prevention and may help to establish clinical benchmarks for beneficial 25(OH)D levels,” the authors conclude.