Vitamin B12

A B vitamin the body needs to form red blood cells and help convert food into energy.

Supplement

What it is

B vitamins, including vitamin B12, help the process the body uses to get or make energy from food, and also help form red blood cells. A lack of B12 can cause anemia. Common supplement/prescription forms include cyanocobalamin and methylcobalamin.

How it is commonly taken

Cyanocobalamin tablets are usually taken with a meal or as directed by a doctor, and people are generally advised to continue their normal diet unless told otherwise.

Known interaction categories

Insufficient evidence
Monitor

Published interaction pages on this site

Sources

B Vitamins — MedlinePlus, U.S. National Library of Medicine Cyanocobalamin (Vitamin B12) — MedlinePlus, U.S. National Library of Medicine

Last reviewed 2026-08-22

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.