Safety and side effects

When used orally at appropriate doses, folic acid is likely safe.

Oral use of folic acid can cause:

• Bad taste in your mouth
• Nausea
• Loss of appetite
• Confusion
• Irritability
• Sleep pattern disturbance

People with allergies might have a reaction to folic acid supplements. Warning signs of an allergic reaction include:

• Skin rash
• Itching
• Redness
• Difficulty breathing

Excess folic acid is excreted in urine.

A high folate intake can mask vitamin B-12 deficiency until its neurological effects become irreversible. This can typically be remedied by taking a supplement containing 100 percent of the daily value of both folic acid and vitamin B-12.