Fortification with low amounts of folic acid makes a significant difference in folate status in young women: implications for the prevention of neural tube defects

Background: Mandatory fortification of grain products with folic acid was i ntroduced recently in the United States, a policy expected to result in a m ean additional intake of 100 mu g/d. One way of predicting the effectivenes s of this measure is to determine the effect of removing a similar amount o f folic acid as fortified food from the diets of young women who had been e lectively exposed to chronic fortification. Objective: The objective was to examine the effect on folate status of food s fortified with low amounts of folic acid. Design: We investigated the changes in dietary intakes and in red blood cel l and serum concentrations of folate in response to removing folic acid-for tified foods for 12 wk from the diets of women who reportedly consumed such foods at least once weekly (consumers). Results: Consumers (n = 21) had higher total folate intakes (P = 0.002) and red blood cell folate concentrations (P = 0.023) than nonconsumers (women who consumed folic acid-fortified foods less than once weekly; n = 30). Of greater interest, a 12-wk intervention involving the exclusion of these foo ds resulted in a decrease in folate intake of 78 +/- 56 mu g/d (P < 0.001), which was reflected in a significant reduction in red blood cell folate co ncentrations (P < 0.05). Conclusions: Cessation of eating folic acid-fortified foods resulted in rem oving 78 mu g folic acid/d from the diet. Over 12 wk this resulted in a low ering of red blood cell folate concentrations by 111 nmol/L (49 mu g/L). Th is magnitude of change in folate status in women can be anticipated as a re sult of the new US fortification legislation and is predicted to have a sig nificant, although not optimal, effect in preventing neural tube defects.