Vitamin D intake, blood vitamin D levels, and the risk of breast cancer: a dose-response meta-analysis of observational studies.
Epidemiological studies have indicated that blood vitamin D levels are linked to cancer. Here we conducted a dose-response meta-analysis based on published observational studies to evaluate the association of vitamin D intake and blood vitamin D levels with breast cancer susceptibility. PubMed, EMBASE, and Web of Science databases were searched up to January 2019. The pooled odds ratio (OR) and 95% confidence intervals (CIs) were extracted to estimate the risk. We identified 70 relevant studies on blood vitamin D levels (50 studies) and vitamin D intake (20 studies), respectively. Linear and nonlinear trend analyses were performed and showed that an increase in blood vitamin D levels by 5 nmol/l was associated with a 6% decrease in breast cancer risk (OR = 0.94, 95% CI = 0.93-0.96). Similar results were obtained for premenopausal (OR = 0.96, 95% CI = 0.93-0.99) and postmenopausal women (OR = 0.96, 95% CI = 0.94-0.98). The pooled OR of breast cancer risk for a 400IU/day increase in vitamin D intake was 0.97 (95% CI = 0.92-1.02). In conclusion, we found that breast cancer risk was inversely related to blood vitamin D levels; however, no significant association was observed in vitamin D intake.
['Song|Dingli|D|', 'Deng|Yujiao|Y|', 'Liu|Kang|K|', 'Zhou|Linghui|L|', 'Li|Na|N|', 'Zheng|Yi|Y|', 'Hao|Qian|Q|', 'Yang|Si|S|', 'Wu|Ying|Y|', 'Zhai|Zhen|Z|', 'Li|Hongtao|H|', 'Dai|Zhijun|Z|']
D001943:Breast Neoplasms D004305:Dose-Response Relationship, Drug D005260:Female D006801:Humans D012307:Risk Factors D014807:Vitamin D D014808:Vitamin D Deficiency
vitamin D dose-response meta-analysis breast cancer risk menopause