Lack of effect of long-term supplementation with beta carotene on the incidence of malignant neoplasms and cardiovascular disease. - Hennekens,C..H..; Buring,J..E..; Manson,J..E..; Stampfer,M..; Rosner,B..; Cook,N..R..; Belanger,C..; LaMotte,F..; Gaziano,J..M..; Ridker,P..M..; Willett,W..; Peto,R.. (N Engl J Med, 1996)