title: Assessing cancer prevention studies--a matter of time.
authors.forename: Bettina F
authors.initials: BF
authors.lastname: Drake
authors.forename: Graham A
authors.initials: GA
authors.lastname: Colditz
mesh_terms: D019587:Dietary Supplements / Q000009:adverse effects; D005492:Folic Acid / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D009369:Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D018570:Risk Assessment; D013997:Time Factors; D014805:Vitamin B 12 / Q000009:adverse effects / Q000627:therapeutic use*; D014803:Vitamin B Complex / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D014803:Vitamin B Complex; D005492:Folic Acid; D014805:Vitamin B 12