Folic acid added to wholemeal flour and folate intake in Canadians
What it found
Modelling suggests adding folic acid to wholemeal flour would raise folate intake slightly across the Canadian population and cut folate inadequacy among adult wholemeal consumers.
The work used dietary survey data, not new measurements in people.
What they found
Folate intake rise
Mean folate intakes rose by about 5% in all sex and age groups when wholemeal foods were fortified, whether or not a 50% overage was included. For example, women aged 19 to 30 who did not take a supplement went from 419 to 441 micrograms of dietary folate equivalents per day.
General population inadequacy
Fortifying wholemeal flour foods did not change the prevalence of folate inadequacy or the percentage of intakes above the upper level in the general population, whether people took supplements or not.
Wholemeal consumers
Among adult wholemeal consumers who did not take a folic acid supplement, the prevalence of folate inadequacy fell from 21% to 10% with mandatory-level fortification, and from 10% to 3% with a 50% overage. Among supplement users, considering food sources only, it fell from 26% to 13% or from 12% to 4% with the overage.
Upper level intakes
No wholemeal consumers went above the upper level for folic acid from food alone, at any modelled fortification level. Between 13% and 18% of wholemeal consumers who took a folic acid supplement went above the upper level, and this did not rise significantly with fortification.
Elderly women
Women over 71 had the highest prevalence of dietary folate inadequacy. Among those not taking supplements it was about 58%, falling to 46% after modelling wholemeal fortification, but this change was not significant.
What the authors conclude
“Although folic acid fortification of whole-wheat flour-containing foods is unlikely to change the POFI or proportion of folic acid intakes above the UL in the general Canadian population, this fortification strategy may reduce the POFI in adult whole-wheat consumers.”
Also in their conclusions
- They conclude that fortifying wholemeal flour foods would increase total folate intake in the Canadian population and improve folate inadequacy in adult wholemeal consumers without increasing the proportion of people above the upper level.
- They say adding folic acid to wholemeal flour foods would likely not significantly change folate inadequacy or the prevalence of intakes above the upper level in the general Canadian population.
- They advise that a future modelling exercise using more current local data is warranted.
How it was done
Mandatory folic acid fortification of white flour has reduced neural tube defects in Canada, but wholemeal flour is not fortified. The authors wanted to see how fortifying wholemeal flour would affect folate intake, since Canadians are encouraged to eat more whole grains.
They used 24-hour dietary recall and supplement data from 35,107 people in the 2004 Canadian Community Health Survey 2.2. They modelled adding folic acid to wholemeal flour foods at the level mandatory for white flour, and also with a 50% overage, then estimated usual folate intakes.
What it can’t tell you
- This is a modelling exercise based on dietary survey data from 2004, so it estimates what might happen rather than measuring real intakes after fortification.
- The survey data may not reflect current eating habits, since wholemeal consumption may have increased since 2004.
- The models cannot show whether fortifying wholemeal flour would actually reduce neural tube defects or other health outcomes.
Who paid
- Authors work at
- University of Toronto, Canada; The Research Institute, Canada
The paper
- Title
- Modeling Demonstrates That Folic Acid Fortification of Whole-Wheat Flour Could Reduce the Prevalence of Folate Inadequacy in Canadian Whole-Wheat Consumers
- Type
- Study
- Summarised from
- Full text
- Cite
- Chan YM, MacFarlane AJ, O'Connor DL (2015). Modeling Demonstrates That Folic Acid Fortification of Whole-Wheat Flour Could Reduce the Prevalence of Folate Inadequacy in Canadian Whole-Wheat Consumers. The Journal of nutrition. doi:10.3945/jn.115.217851Free full textPubMed 26423740DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error