Evaluation of the safety of different doses of folic acid supplements in women in Brazil

Abstract

OBJECTIVE To evaluate the distribution of folic acid intake and the safety of different doses of supplements in women of childbearing age. METHODS Data were used from two non-consecutive days of food records of 6,837 women of childbearing age (19-40 years old) participants of the National Food Survey, a module of the Household Budget Survey 2008-2009. Means and percentiles of usual consumption of natural folate and folic acid were estimated using the National Cancer Institute method. Five scenarios were simulated by adding different daily doses of fortification (400 mcg, 500 mcg, 600 mcg, 700 mcg and 800 mcg) to folic acid derived from food consumed by the women. To define a safe dose of the supplement, the total folate (dietary + supplement) was compared with the tolerable upper intake level (UL = 1,000 mcg). RESULTS Women with usual intake of folic acid above the tolerable upper intake levels were observed only for doses of supplement of 800 mcg (7.0% of women). Below this value, any dose of the supplement was safe. CONCLUSIONS The use of supplements of up to 700 mcg of folic acid was shown to be safe.