Prospective study of coronary heart disease incidence in relation to fasting total homocysteine, related genetic polymorphisms, and B vitamins: the Atherosclerosis Risk in Communities (ARIC) study - Folsom, AR; Nieto, FJ; McGovern, PG; Tsai, MY; Malinow, MR; Eckfeldt, JH; Hess, DL; David, CE (Circulation, 1998)