What are the treatment options for vitamin B12 deficiency?

A clinician may first confirm the deficiency with a blood test and consider diet, reduced absorption, medicines or another health condition as possible contributors. Tablets may be suitable when the gut can absorb B12 and the deficiency is linked to intake. An injection places B12 into muscle and may be chosen when absorption is impaired, symptoms affect the nervous system, or a quicker replacement plan is needed. Treatment can be temporary or ongoing depending on the cause.

Arrange a clinical review before starting high-dose supplements, especially if you have numbness, balance changes, marked tiredness or a restricted diet. Take prescribed tablets as directed, or attend scheduled injection appointments. Keep a list of medicines and supplements, and mention stomach or bowel surgery, digestive symptoms and dietary patterns. Follow-up blood tests may help show whether replacement is working; do not stop a planned course because symptoms begin to improve.

Seek urgent medical help for new weakness, trouble walking, confusion, fainting, chest pain or severe breathlessness. Contact a clinician promptly if symptoms are worsening, you cannot keep tablets down, or an injection site becomes increasingly red, hot, swollen or painful. These symptoms need assessment rather than a change to your supplement dose alone.

Ask what caused the deficiency, whether tablets or an injection fit your situation, how long replacement may be needed, and which symptoms should trigger an earlier review.