Vitamin B12

Vitamin B12 is needed for red blood cell formation and healthy nerves. Supplements are used when a diet does not provide enough, including vegan diets, and as treatment for deficiency. Absorption problems can also cause deficiency even when you eat foods containing B12. Tablets, sprays and injections are available; the reason for treatment matters when choosing a form.

B12 is widely marketed for tiredness, but feeling exhausted does not establish a deficiency. An “energy” label cannot explain your symptoms. Persistent tiredness, tingling or balance problems need medical assessment. Buying a supplement and waiting can delay finding the cause.

You may feel nothing when you take B12. It is not a stimulant, and a prescribed treatment does not need to produce an immediate sensation to have a purpose. Follow-up for deficiency considers your symptoms as well as laboratory results.

Injections can cause pain, swelling or itching at the injection site. Report ongoing or new symptoms instead of assuming they are part of recovery. Paying for an injection at a wellness clinic does not establish that you need it or replace investigating persistent tiredness.

Tablets are usually well tolerated, but B12 contains cobalt: tell your clinician about a cobalt allergy. Swelling of the mouth or throat or trouble breathing needs emergency help. Metformin and some acid-suppressing medicines can reduce B12 absorption; do not stop them on your own.

Supplements can complicate the interpretation of B12 blood tests, so disclose everything you take, including multivitamins. Needing ongoing replacement because of an absorption problem is not dependence. Stopping prescribed treatment when you feel better may allow deficiency to return; review its duration with your clinician.