What are the symptoms of B12 deficiency?

Written by Tod Cooperman, M.D.

Updated May 14, 2019 ⓘ

Symptoms of B12 Deficiency -- paper with question "Are you getting enough vitamin B12" and boxes to check yes or no

Answer:

Vitamin B12 helps make the genetic material in all cells, so deficiency can have wide-ranging effects. These commonly include anemia, as well as fatigue, depression, tingling in the arms and legs, loss of balance, as well as skin and hair changes. In some cases, B12 deficiency may reduce immunity.

Older adults are more likely to experience B12 deficiency. Strict vegetarians and people taking medications that decrease stomach acid, such as Prevacid and Prilosec, or those taking the anti-diabetes drug metformin, are also more likely to become deficient. B12 supplements can correct a deficiency, and B12 injections are typically not necessary.

For more details, see the Vitamin B12 section of the B Vitamin Supplements Review. Also see our Top Picks for B12 supplements.

Keep in mind that getting too much B12 can cause adverse effects, and many B vitamin supplements contain more B12 than necessary and can be absorbed.