25(OH)D serum levels 蠅 50 ng/mL may provide additional reduction in breast cancer risk (628.12)

Higher serum 25-hydroxyvitamin D [25(OH)D] concentrations are associated with a lower risk of breast cancer. Serum levels in the range of 40 to 60 ng/mL could prevent a substantial number of breast cancer cases. This study examined the relationship between serum 25(OH)D and the incidence of breast cancer among women aged 60 years and older. The study included the 771 participants of the GrassrootsHealth cohort who were followed prospectively for a median of 12 months. There were 5 self-reported incident breast cancer cases within the study period. The median 25(OH)D concentration in this cohort was 50 ng/ml and the median age was 65 years. Four of the five cases had 25(OH)D values below the median for the group as a whole. Cox multivariate regression was used to assess the association between serum 25(OH)D concentration and incidence of breast cancer, adjusting for age. The hazard ratio of breast cancer in participants with a serum 25(OH)D concentration < 50 ng/mL was 5.1 (95% CI=0.56, 45.7) compared to 蠅...