A comparison of the effect of advice to eat either ‘5-a-day’ fruit and vegetables or folic acid-fortified foods on plasma folate and homocysteine

Objective: To assess and compare the effects of natural folate (100 microg) with those of folic acid from fortified sources (100 microg/day) on plasma folate and homocysteine. Design: Randomized controlled trial (parallel groups). Setting: Men and women living in South Wales, UK. Subjects: A total of 135 healthy individuals recruited from the local workforce and blood donor sessions. All subjects possessed the 'wild-type' CC genotype for C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR). Interventions: Subjects underwent one of the following dietary interventions for 4 months: (1) fortified diet—usual diet plus 100 microg/day folic acid from fortified foods; (2) natural folate diet—usual diet plus 100 microg/day folate from natural sources; (3) control—usual diet. Results: The fortified group increased reported intake of folic acid from fortified foods compared to other groups (P