Plasma B-vitamin and one-carbon metabolites and risk of breast cancer before and after folic acid fortification in the United States.

ABSTRACT: Prior epidemiologic findings for plasma folate and B-vitamins and breast cancer risk are inconsistent and have not assessed the influence of folic acid fortification. Therefore, we examined the associations of plasma folate, B₁₂ , pyridoxal 5'-phosphate (PLP), homocysteine, cysteine and cysteinylglycine with breast cancer risk, before and after fortification. We conducted a nested case-control study within the prospective Nurses' Health Study. In 1989-1990 (pre-fortification), 32,826 women donated a blood sample and 18,743 donated an additional blood sample in 2000-2001 (post-fortification). Between the first blood collection and 2006, 1874 incident breast cancer cases with at least one blood sample and 367 with two were 1:1 matched to controls. Conditional logistic regression w

SUBMITTER: Houghton SC 

PROVIDER: S-EPMC7895336 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature