Is There a Difference in the Absorption of Folic Acid and Folate?
Folic Acid is the synthetic oxidized form of folate that is most frequently used in dietary supplements. Folic acid was also the form that was used to fortify grain products in the US when the FDA began a mandatory fortification program in 1996. This has been credited with dramatically improving the folate status in women of childbearing age and reducing the incidence of distressing neural tube birth defects like spina bifida by up to 50%. Natural food folate is different from folic acid, in that comes in many forms and is further distinguished from folic acid in that it has a long tail. This has a big impact on the ease with which it gets absorbed and it is approximately 40% less bioavailable than folic acid.
To account for the differences in bioavailability, folate recommended intakes are often given in units called DFEs (Dietary Folate Equivalents). 1 microgram of natural folate equals 1 DFE and 1 microgram of folic acid equals 1.7 DFE