title: Vitamin D and prevention of breast cancer: pooled analysis.
abstract: BACKGROUND
  Inadequate photosynthesis or oral intake of Vitamin D are associated with high incidence and mortality rates of breast cancer in ecological and observational studies, but the dose-response relationship in individuals has not been adequately studied.
  
  
  METHODS
  A literature search for all studies that reported risk by of breast cancer by quantiles of 25(OH)D identified two studies with 1760 individuals. Data were pooled to assess the dose-response association between serum 25(OH)D and risk of breast cancer.
  
  
  RESULTS
  The medians of the pooled quintiles of serum 25(OH)D were 6, 18, 29, 37 and 48 ng/ml. Pooled odds ratios for breast cancer from lowest to highest quintile, were 1.00, 0.90, 0.70, 0.70 and 0.50 (p trend<0.001). According to the pooled analysis, individuals with serum 25(OH)D of approximately 52 ng/ml had 50% lower risk of breast cancer than those with serum <13 ng/ml. This serum level corresponds to intake of 4000 IU/day. This exceeds the National Academy of Sciences upper limit of 2000 IU/day. A 25(OH)D level of 52 ng/ml could be maintained by intake of 2000 IU/day and, when appropriate, about 12 min/day in the sun, equivalent to oral intake of 3000 IU of Vitamin D(3).
  
  
  CONCLUSIONS
  Intake of 2000 IU/day of Vitamin D(3), and, when possible, very moderate exposure to sunlight, could raise serum 25(OH)D to 52 ng/ml, a level associated with reduction by 50% in incidence of breast cancer, according to observational studies.
authors: Department of Family and Preventive Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA. cgarland@ucsd.edu
authors: Cedric F
authors: CF
authors: Garland
authors: Edward D
authors: ED
authors: Gorham
authors: Sharif B
authors: SB
authors: Mohr
authors: William B
authors: WB
authors: Grant
authors: Edward L
authors: EL
authors: Giovannucci
authors: Martin
authors: M
authors: Lipkin
authors: Harold
authors: H
authors: Newmark
authors: Michael F
authors: MF
authors: Holick
authors: Frank C
authors: FC
authors: Garland
mesh_terms: D000284:Administration, Oral; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control*; D006801:Humans; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
chemical_list: D014807:Vitamin D