Circulating unmetabolized folic acid and 5-methyltetrahydrofolate and risk of breast cancer: a nested case-control study.
Karen L KoenigStephanie ScarmoYelena AfanasyevaTess V ClendenenPer Magne UelandAnne Zeleniuch-JacquottePublished in: European journal of clinical nutrition (2020)
Circulating UMFA was not associated with breast cancer risk. These results apply to countries without mandatory FA food fortification. Studies are needed in countries with mandatory fortification, where levels of UMFA are much higher than in our study.