Alcohol and vitamin B deficiency

Several B vitamins may be affected, so symptoms and treatment depend on which nutrient is low. A clinician can assess eating patterns, alcohol use, symptoms and blood results rather than relying on symptoms alone.

Alcohol can replace balanced meals, irritate the digestive tract and interfere with nutrient processing in the liver. Vomiting or diarrhoea can add to poor intake. Folate, thiamine and vitamin B12 support blood cells, nerves and normal energy metabolism, but a deficiency in one does not prove that alcohol is the cause.

Possible features include tiredness, weakness, a sore tongue, pale skin, numbness, tingling, unsteady walking or changes in memory and concentration. Vitamin B12 deficiency can also affect nerves, while anaemia can develop with folate or B12 deficiency.

Arrange a medical review if symptoms persist or your diet has become restricted. Bring a list of medicines and supplements, and describe how much and how often you drink honestly. Tests may include a full blood count and selected vitamin levels; other tests depend on the symptoms and examination.

Do not treat a suspected deficiency with high-dose supplements alone. The correct vitamin, dose and route depend on the cause, and taking folic acid without checking vitamin B12 can make blood results improve while nerve injury continues. If you drink heavily or develop shaking, sweating or agitation when you stop, seek medical advice before suddenly stopping because withdrawal can be dangerous.

Seek urgent care for new confusion, marked drowsiness, trouble walking, abnormal eye movements, repeated vomiting, a seizure or loss of consciousness. These symptoms can accompany a serious thiamine-related brain problem or another acute illness and should not wait for a routine appointment.

Prompt assessment is also appropriate for worsening numbness, weakness, breathlessness, fainting or a rapidly declining ability to eat and drink.

Ask which B vitamins need checking, whether your blood count or nerve examination suggests a deficiency, and whether treatment should be tablets or injections. You can also ask for support to reduce alcohol safely and for guidance on meals that fit your health needs.