Vitamin D and prevention of breast cancer: pooled analysis.
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.
Garland
Cedric F
CF
Department of Family and Preventive Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA. cgarland@ucsd.edu
Gorham
Edward D
ED
Mohr
Sharif B
SB
Grant
William B
WB
Giovannucci
Edward L
EL
Lipkin
Martin
M
Newmark
Harold
H
Holick
Michael F
MF
Garland
Frank C
FC
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*
D014807:Vitamin D