Can I Take These?

Can You Take Folate / Folic Acid and Vitamin B12 Together?

Folate's own NIH fact sheet warns that high-dose folate supplements can hide the signs of a vitamin B12 deficiency.

MonitorEvidence: High

See the full Folate / Folic Acid page and Vitamin B12 page for other reviewed interactions and reference information.

What the interaction means

The NIH Office of Dietary Supplements' Folate — Consumer fact sheet states: "Taking large amounts of folate supplements might hide a vitamin B12 deficiency because these supplements can correct the anemia that the vitamin B12 deficiency causes but not the nerve damage that the vitamin B12 deficiency also causes... Large doses of folate supplements might also worsen the symptoms of vitamin B12 deficiency." The Health Professional version adds that this concern has historically centered on high intakes masking the anemia of B12 deficiency "until its neurological consequences become irreversible," though it also notes ongoing scientific debate about how large a real-world risk this is.

Why it may happen

Folate can correct the megaloblastic anemia caused by vitamin B12 deficiency without correcting the underlying B12 deficiency itself, so the anemia (often the first noticeable warning sign) can resolve while the deficiency's neurological damage continues progressing undetected.

Practical context

This concern is specifically about large/high-dose folate or folic acid supplementation, not typical dietary folate intake or standard multivitamin doses. People taking folate supplements, especially at higher doses, may want to also have their vitamin B12 status checked periodically, particularly if they are in a group at elevated risk of B12 deficiency (e.g., older adults, those with reduced stomach acid, or people on long-term metformin or acid-reducing medications).

What the sources say

Folate — Consumer — NIH Office of Dietary SupplementsFolate — Health Professional Fact Sheet — NIH Office of Dietary Supplements

Last reviewed 2026-08-24

Medical information disclaimer: this information is general and educational. It does not diagnose conditions, prescribe treatment, or determine whether a combination is safe for you personally. Follow your prescription label and ask a pharmacist or clinician before starting, stopping, or combining products. Full disclaimer.

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