Meta-analysis of vitamin D, calcium and the prevention of breast cancer.
Vitamin D and calcium intake have been suggested to have protective effects against breast cancer; however, the data have been inconclusive. The present meta-analysis examined the overall effects of vitamin D intake, circulating 25(OH)D and 1alpha,25(OH)(2)D levels, and calcium intake on breast cancer risk. Data from 11 studies on vitamin D intake, 7 studies on circulating 25(OH)D levels, 3 studies of circulating 1alpha,25(OH)(2)D levels, and 15 studies on calcium intake and breast cancer risk were included in this analysis. From the meta-analysis, there was a significant inverse relationship between vitamin D intake and breast cancer risk, with an overall relative risk (RR) of high versus low vitamin D intake for breast cancer of 0.91 (95% CI = 0.85-0.97). The highest quantile of circulating 25(OH)D was found to be associated with a 45% (OR = 0.55, 95% CI = 0.38-0.80) decrease in breast cancer when compared with the lowest quantile. No significant association for the circulating 1alpha,25(OH)(2)D level and breast cancer was found (OR = 0.99, 95% CI = 0.68-1.44). For calcium, a 19% (RR = 0.81, 95% CI = 0.72-0.90) decrease in breast cancer risk was found for those with highest quantile of calcium intake compared to the lowest quantile. These results provide strong evidence that vitamin D and calcium have a chemopreventive effect against breast cancer.
Chen
Peizhan
P
Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Rm 427, 41# Building, 320 Yueyang Road, 200031 Shanghai, People's Republic of China.
Hu
Pingting
P
Xie
Dong
D
Qin
Ying
Y
Wang
Fudi
F
Wang
Hui
H
D001943:Breast Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D002118:Calcium / Q000494:pharmacology*; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D012307:Risk Factors; D014807:Vitamin D / Q000494:pharmacology*; D014815:Vitamins / Q000494:pharmacology*
D014815:Vitamins; D014807:Vitamin D; D002118:Calcium