If you’ve heard that folic acid is being added to flour and wondered what that means for your morning toast, you’re in good company.
It’s fair to ask why a vitamin is being added to a food eaten by millions of people. The answer starts with what happens in the first few weeks of pregnancy.
What is folic acid?
Folate is vitamin B9. You’ll find it naturally in spinach, broccoli, peas and chickpeas. Folic acid is the manufactured form used in supplements and fortified foods, including some breakfast cereals. Your body needs folate to make healthy red blood cells, and too little can lead to folate deficiency anaemia.
Why add it to flour?
Taking folic acid before conception and in early pregnancy reduces the risk of neural tube defects such as spina bifida.
The neural tube, which develops into the brain and spinal cord, forms very early, often before someone knows they’re pregnant. Adding folic acid to a staple food helps reach people during those crucial weeks.
The Food Standards Agency estimates that fortification could cut UK rates of neural tube defects by around 20%. food.gov.uk
From 13 December 2026, UK rules require 250 micrograms of folic acid per 100g of most non-wholemeal common wheat flour. Wholemeal flour is exempt. The NHS still advises taking 400 micrograms daily when trying for a baby, ideally starting three months before conception, and continuing through the first 12 weeks of pregnancy. Some people are prescribed a higher dose. GOV.UK
What about the safety claims?
Can it hide a vitamin B12 deficiency? High doses can correct the anaemia caused by B12 deficiency while the underlying deficiency goes untreated and can still damage nerves. The NHS warns doses above 1 milligram (1,000 micrograms) can mask symptoms. UK scientific advisers found after US fortification, there was no increase in the prevalence of B12 deficiency with or without anaemia.
Does it cause cancer? An analysis of trials involving nearly 50,000 people found no statistically significant increase in overall cancer rates over about five years. The trials generally used doses higher than those supplied by fortification. That finding is reassuring for the period studied. pubmed.ncbi.nlm.nih.gov
What if I have an MTHFR gene variant? People with common MTHFR variants can still process folic acid, and the recommended dose raises blood folate levels.
The evidence supports the amount being added to flour. If you already take several supplements, it’s worth checking the labels, as a multivitamin and a separate B-vitamin tablet can both contain folic acid.