BRCA1 and breast cancer: When adjusting for age, BRCA1/2 pathogenic germline gene variant, BMI, parity, alcohol consumption and smoking status, consumption of any folic-acid containing supplement, 8.56–89.29mcg/d of folic acid supplementation, and 0.02–0.34 mcg/d of B12 supplementation, was associated with reduced likelihood of breast cancer among women with BRCA1/2 pathogenic germline gene variants [27].