How much folate is in Canadian fortified products 10 years after mandated fortification?

Objective: In 1998, the Canadian government mandated folic acid fortification of white flour and enriched grain products to lower the prevalence of neural tube defects. There is now growing concern over the potential harmful effects of too much folic acid on some segments of the population. Given that the actual amount of folate in Canadian foods is unknown, the objective of this study was to measure the folate content in selected fortified foods.

Methods: Using data from the 2001 Food Expenditure Survey and the ACNielsen Company, 95 of the most commonly purchased folic acid-fortified foods in Canada were identified. Folate concentrations in these foods were determined using tri-enzyme digestion followed by microbiological assay. Analyzed values were compared to those in the Canadian Nutrient File (2007b, CNF) and to label values.

Results: The analyzed folate content of foods was, on average, 151% +/- 63 of the CNF values. Analyzed values as a percent of CNF values ranged from 116% in the "rolls and buns" category to 188% in "ready-to-eat cereals". Analyzed values were higher than label values for "breads", "rolls and buns" and "ready-to-eat cereals" (141%, 118% and 237%, respectively [p < 0.05]).

Conclusions: Ten years after folic acid fortification of the food supply, neither the CNF nor label values accurately reflect actual amounts of folate in foods. Further, overage differences by food category hinder the development of future strategies designed to strike the right balance between health benefits and risks; monitoring of fortified foods for their nutrient content is required.