Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Nov 15;139(10):2193-200.
doi: 10.1002/ijc.30282. Epub 2016 Jul 30.

Postmenopausal Breast Cancer Risk and Interactions Between Body Mass Index, Menopausal Hormone Therapy Use, and Vitamin D Supplementation: Evidence From the E3N Cohort

Affiliations
Free article

Postmenopausal Breast Cancer Risk and Interactions Between Body Mass Index, Menopausal Hormone Therapy Use, and Vitamin D Supplementation: Evidence From the E3N Cohort

Claire Cadeau et al. Int J Cancer. .
Free article

Abstract

Experimental studies suggest protective effects of vitamin D on breast carcinogenesis, but epidemiological evidence is not conclusive. Body mass index (BMI) has been shown to modulate the effect of supplementation on the vitamin D status, but its potential influence on the relationship with breast cancer risk has been little studied. We investigated a potential interaction between BMI and vitamin D supplementation on breast cancer risk while considering an already reported interaction between vitamin D supplementation and menopausal hormone therapy (MHT) use. Vitamin D supplementation was prospectively investigated in 57,403 postmenopausal women from the French E3N cohort including 2,482 incident breast cancer cases diagnosed between 1995 and 2008. Multivariable hazard ratios (HR) for primary invasive breast cancer and 95% confidence intervals (CI) were estimated using Cox models. Among MHT ever users, vitamin D supplementation was associated with decreased breast cancer risk, similarly across BMI strata (Phomogeneity = 0.83). Among MHT never users, ever vitamin D supplementation was associated with increased postmenopausal breast cancer risk in women with baseline BMI <25 kg/m(2) (HR = 1.51, 95% CI: 1.13, 2.02), but not in women with higher BMI (0.98, 95% CI: 0.62, 1.56), Phomogeneity = 0.12. In conclusion, our findings suggest that vitamin D supplementation may reduce the excess breast cancer risk in MHT users, but draw attention on a potential risk in postmenopausal women not exposed to high exogenous or endogenous hormones, i.e. non-overweight MHT-non users, especially in the present context of increasing vitamin D supplement use and decreasing MHT use.

Keywords: BMI; breast cancer; cohort; supplements; vitamin D.

Similar articles

See all similar articles

Cited by 6 articles

See all "Cited by" articles

Publication types

Feedback