Fig. 5

Distributions of folate intake with and without mandatory folic acid (FA) fortification (mean intake from mandatory fortification 0.2 mg/day) with (b) and without (a) adjustment for folic acid bioavailability. The percentage of people with a folate intake > 1 mg/day is shown in the boxes with and without mandatory fortification. Distributions include background intake from natural food folate and voluntary folic acid fortification. [Data on the usual intake of natural food folate and voluntary folic acid fortification in the UK from the National Diet and Nutrition Survey (NDNS 2008/9–2013/14) [20]. Almost identical distributions are obtained using the usual intake of folate in the USA from the Continuing Survey of Food Intakes by Individuals [21]. Intake from mandatory folic acid fortification assumed to be independent of natural food folate and folic acid from voluntary fortification but with the same population variance]