Breast Cancer risk reduced 12 percent if recently used some amount of Vitamin D – Jan 2022

Vitamin D Supplement Use and Risk of Breast Cancer by Race-Ethnicity

Epidemiology. 2022 Jan 1;33(1):37-47. doi: 10.1097/EDE.0000000000001413.
Katie M O'Brien 1, Alexander P Keil 1 2, Quaker E Harmon 1, Chandra L Jackson 1 3, Alexandra J White 1, Mary V Díaz-Santana 4, Jack A Taylor 1, Dale P Sandler 1

Background: Vitamin D has anticarcinogenic properties, but a relationship between vitamin D supplement use and breast cancer is not established. Few studies have accounted for changes in supplement use over time or evaluated racial-ethnic differences.

Methods: The Sister Study is a prospective cohort of 50,884 women with 35-74 years of age who had a sister with breast cancer, but no breast cancer themselves at enrollment (2003-2009). We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between vitamin D supplement use and incident breast cancer (3,502 cases; median follow-up 10.5 years).

Results: Vitamin D supplement use was common, with 64% reporting ever use (at least once per month) in the year before enrollment. Considering supplement use over time, ever use of vitamin D supplements was not meaningfully associated with breast cancer (HR = 0.96, 95% CI = 0.88, 1.0), relative to never use.
However, after adjusting for prior use, recent use of vitamin D supplements ≥1/month was inversely associated with breast cancer (HR = 0.88, 95% CI = 0.78, 1.0), relative to nonrecent use.
The inverse association was stronger for

• ductal carcinoma in situ (HR = 0.67, 95% CI = 0.52, 0.87) than
• invasive breast cancer (HR = 0.94, 95% CI = 0.72, 1.1, p-for-heterogeneity = 0.02).

Supplement use was less common among African American/Black (56%) and non-Black Hispanic/Latina (50%) women than non-Hispanic White women (66%), but there was limited evidence of racial-ethnic differences in HRs (p-for-heterogeneity = 0.16 for ever use, P = 0.55 for recent).

Conclusions: Our findings are consistent with the hypothesis that recent vitamin D use is inversely associated with breast cancer risk

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VitaminDWiki - Overview Breast Cancer and Vitamin D contains:

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