The CDC advises 400 mcg of folic acid a day for anyone who could become pregnant, starting at least one month before trying. Many conception formulas use L-methylfolate, the active form of folate, which the body can use without converting it first.
Daily amount
400 mcg
Folate every day while trying to conceive. Labels show it in mcg DFE.
When to start
1 month
At least one month before trying, so folate stores are built before conception.
Upper limit
1,000 mcg
Folic acid from supplements and fortified foods, per the NIH. Add up every product you take.
Daily amount and timing from the CDC, About Folic Acid. Upper limit from the NIH Office of Dietary Supplements folate fact sheet, for folic acid from supplements and fortified foods in adults.
Why the timing is before trying
The CDC advises 400 mcg of folic acid every day for anyone who could become pregnant, starting at least one month before trying. Folate supports cell division in the earliest weeks after conception, often before a positive test, so the stores need to be in place first.
Food folate from greens and beans is useful, but the CDC says it is hard for most people to reach the recommended amount from food alone. The routes the CDC recommends are a supplement or fortified foods.
Folic acid and L-methylfolate
Folic acid is the synthetic form used in fortified foods and most public-health research. The body converts it to 5-methyltetrahydrofolate, or 5-MTHF, the active form, with help from an enzyme called MTHFR.
L-methylfolate is that active form already, so it is absorbed and used without the conversion step. People with an MTHFR gene variant convert folic acid less efficiently, which is a common reason they choose a formula with methylfolate. Either way, check the mcg DFE number against the 400 mcg target.
Folate for both partners
Folate also appears on most men's conception formulas, usually next to zinc. It is involved in DNA synthesis, which is why it shows up on labels for sperm health.
If you take a conception formula and a separate multivitamin, add up the folate in both. The NIH upper limit for adults is 1,000 mcg a day of folic acid from supplements and fortified foods.
Sources
These are population recommendations, not a personal dose. A clinician sets the dose for anyone on medicines that affect folate.
This is general information, not medical advice. All research.