Higher blood 25(OH)D level may reduce the breast cancer risk: evidence from a Chinese population based case-control study and meta-analysis of the observational studies

PLoS One. 2013;8(1):e49312. doi: 10.1371/journal.pone.0049312. Epub 2013 Jan 30.

Abstract

Experimental data suggest a protective effect of vitamin D on breast cancer; however, epidemiologic results remain inclusive. With a Chinese population-based case-control study and meta-analysis of the observational studies, we here systematically evaluated the association of blood 25(OH)D level and breast cancer risk. With 593 breast cancer cases and 580 cancer-free controls from Shanghai, China, we found that 80% of the normal women had severe vitamin D deficiency (less than 20 ng/mL) and 15.2% had mild deficiency (20 to 30 ng/mL) and only 4.8% of women had sufficient vitamin D level (>30 ng/mL) while the proportion was 96.1%, 3.2% and 0.7% respectively for the breast cancer patients. Compared to those with the lowest quartile of plasma 25(OH)D level, women with highest quartile 25(OH)D level showed a significant decreased breast cancer risk (Q4 vs.Q1: OR = 0.10, 95% CI = 0.06-0.15) and every 1 ng/ml increment of plasma 25(OH)D level led to a 16% lower odds of breast cancer (OR = 0.84, 95% CI = 0.81-0.87; P<0.001). From the meta-analysis of the observational studies, we found that women with highest quantile of blood 25(OH)D level was associated with a significantly reduced breast cancer risk compared to those with lowest quantile of blood 25(OH)D level for the 11 nested case-control and retrospective studies (pooled OR = 0.86, 95% CI = 0.75-1.00) and 10 case-control studies (7 population based, OR = 0.35, 95% CI = 0.24-0.52; 3 hospital based, OR = 0.08, 95% CI = 0.02-0.33). These results suggest that vitamin D may have a chemo-preventive effect against breast cancer.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / blood
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Case-Control Studies
  • Female
  • Genetic Association Studies*
  • Humans
  • Middle Aged
  • Retrospective Studies
  • Risk Factors
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood
  • Vitamin D / genetics*
  • Vitamin D / metabolism

Substances

  • Vitamin D
  • 25-hydroxyvitamin D

Grant support

This study was supported by grants from the One Hundred Talents Program of the Chinese Academy of Sciences, the National Nature Science Foundation of China (81125020, 91029715, 31070680, 31101261 and 31070802), the Ministry of Science and Technology of China (2012BAK01B00, 2011BAK10B00 and 2009CB919000), the Science and Technology Commission of Shanghai Municipality (10391902100), the Science and Technology Commission of Xuhui District of Shanghai Municipality (RCT201001), and Xuhui Central Hospital (CRC2011001 and CRC2011004), Director Foundation (20090101) and the Food Safety Research Center and Key Laboratory of Nutrition and Metabolism of the Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. And in part by the grants from the Science and Technology Commission of Shanghai Municipality (12DZ2260100), National Basic Research Program of China (81172506). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.