Folic acid

Studies in people

• Open question

  Autism risk in children²

  Many people with autism seem to get too little folic acid, but scientists still need better studies to know more.

• Concern

  Chemo treatment side effects³

  In people having capecitabine chemo, taking folic acid supplements was linked to more treatment side effects.

• Benefit

  Ovarian reserve in women⁴

  In women getting fertility treatment, folic acid from food and supplements was linked to a slightly higher egg count.

Study type not stated

• Concern

  Vitamin B12 deficiency⁶

  High-dose folic acid may hide or worsen B12 deficiency, but scientists do not yet know for sure.

• Benefit

  Birth defects in babies⁷

  Folic acid taken before and during pregnancy may lower the chance of some birth defects.

How it’s made and used

• Liver conversion of vitamins⁵

  Folic acid must be turned into its active form by the liver before the body can use it.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least two findings in people. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.