Folic acid in Canadian fortified foods higher than listed
What it found
In 89 fortified foods bought in Canada, the measured folate and folic acid were often higher than the amounts listed in the Canadian Nutrient File and on labels.
The authors say dietary estimates based on these values may underestimate actual intakes.
What they found
Total folate higher
The measured total folate was higher than the Canadian Nutrient File values for all food categories except cooked pasta. On average, it was 65% greater than the CNF values.
Folic acid higher
The measured synthetic folic acid was higher than the CNF values for all categories except cooked pasta. On average, it was 188% of the CNF folic acid values.
Label values low
For breads, rolls and buns, and ready-to-eat cereals, the measured folate was on average 87% higher than the label values. For cooked pasta, label values were 69% higher than the measured values.
Cookies highest
Cookies had the largest difference from CNF values, with measured total folate at 196% of the CNF value and folic acid at 251% of the CNF value.
Extraction method
In a substudy, two extraction methods gave similar results for most foods, but for rolls and buns and crackers, one method gave lower folate values.
What the authors conclude
- They conclude that actual folate and folic acid levels in fortified foods continue to be significantly higher than mandated levels 20 years after fortification.
- They do not recommend that dietary data be used alone to assess the folate adequacy of Canadians either at the individual or population level.
- They suggest that providing a range of the potential folate content might be more informative and may more accurately reflect what is known about the folate content of most folic acid fortified food.
How it was done
The authors wanted to check whether, 20 years after mandatory folic acid fortification began in Canada, the folate values in the Canadian Nutrient File and on food labels match what is actually in the foods.
They bought 89 of the most commonly purchased fortified foods across seven categories in Canada, based on 2001 Food Expenditure Survey and 2007 ACNielsen data. They measured total folate using a microbial assay and synthetic folic acid using LCMS/MS. Foods were analysed as purchased, except pasta, which was cooked first.
What it can’t tell you
- This study measured folate in foods, not in people, so it cannot show what blood folate levels would be in people eating these foods.
- The foods were selected based on purchase data from 2001 and 2007, so they may not represent what Canadians buy today.
- The study did not test whether the higher folate levels in foods cause any health effects.
Who paid
- Conflicts
- The authors have no conflicts of interest relevant to this article to disclose.
- Authors work at
- The Hospital for Sick Children, Canada; University of Toronto, Canada; and Nutrition Evidence Center, USA
The paper
- Title
- Folate and synthetic folic acid content in Canadian fortified foods two decades after mandatory fortification
- Type
- Study
- Summarised from
- Full text
- Cite
- Khanna S, Aufreiter S, MacFarlane A, Shakur Y, O'Connor D (2024). Folate and synthetic folic acid content in Canadian fortified foods two decades after mandatory fortification. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. doi:10.1139/apnm-2024-0063Free full textPubMed 38728750DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error