Folic Acid
Also called Pteroylglutamic acid
Folic acid is the synthetic form of folate used in supplements and food fortification. It must be converted by the MTHFR enzyme (and a chain of other enzymes) into the active 5-MTHF form before the body can use it. For the general population this works adequately, but in individuals with common MTHFR polymorphisms (particularly the C677T variant), this conversion is reduced by 40–70%, leading to elevated homocysteine and lower active folate despite seemingly adequate intake. High doses of unconverted folic acid can also accumulate in the blood. Folic acid remains the most studied and least expensive option for pregnancy supplementation in the general population, and is the form added to fortified grains worldwide.
Best for
General population without MTHFR variants; food fortification
Absorption
Moderate
Tolerability
Well tolerated at standard doses
Typical timing
With or without food; morning is common to support daytime methylation
How to take Folic Acid
A typical dose of Folate (B9): 400–1,000 mcg DFE per day; up to 1,000 mcg L-Methylfolate for MTHFR. Best timing: With or without food; morning is common to support daytime methylation. The form you choose mainly affects absorption and how easily it sits with your stomach, not the overall dose.