Dietary vitamin D and calcium intake and premenopausal breast cancer risk in a German case-control study.
Epidemiological studies and laboratory data suggest that vitamin D may protect against the development of cancer, including breast cancer. Vitamin D supply affects the bioavailability of dietary calcium, which might also have anticarcinogenic effects. However, few studies considered them jointly. We used a population-based case-control study in Germany to examine the independent and joint effects of dietary vitamin D and calcium on premenopausal breast cancer risk. Dietary information was assessed using a validated food frequency questionnaire from 278 premenopausal cases and 666 age-matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariate models adjusting vitamin D models for calcium intake and vice versa. Breast cancer risk was significantly inversely associated with vitamin D intake. The OR and 95% CI for the highest intake category (> or = 5 microg/day) was 0.50 (95% CI = 0.26-0.96) compared with the lowest (< 2 microg/day; P(trend) = 0.02). Dietary calcium intake was not associated with breast cancer (OR = 0.73, 95% CI = 0.41-1.29) for the highest (> or = 1,300 mg/day) versus the lowest category (< 700 mg/day), P(trend) = 0.29). No statistically significant interaction between the 2 nutrients was observed. Our data support a protective effect of dietary vitamin D on premenopausal breast cancer risk independent of dietary calcium intake.
Abbas
Sascha
S
Division of Cancer Epidemiology, German Cancer Research Center, Heidelberg, Germany.
Linseisen
Jakob
J
Chang-Claude
Jenny
J
D000328:Adult; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016022:Case-Control Studies; D016001:Confidence Intervals; D004032:Diet; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D017697:Premenopause; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000008:administration & dosage* / Q000494:pharmacology
D002136:Calcium, Dietary; D014807:Vitamin D