B12 deficiency anemia

Overview

Vitamin B12 deficiency anemia is a condition where your body does not have enough healthy red blood cells because it lacks vitamin B12. Vitamin B12 is needed to make red blood cells, which carry oxygen around your body. When you don't have enough B12, your blood can't carry oxygen as well, making you feel tired and weak.

Vitamin B12 deficiency anemia is not extremely common, but it affects a significant number of people, particularly older adults, people with certain dietary habits, and those with conditions that affect absorption.

It can affect anyone, but it is more common in older adults, people who follow a vegan or vegetarian diet, people with pernicious anemia (an autoimmune condition), people with gastrointestinal disorders like Crohn's disease or celiac disease, and people who have had stomach or intestinal surgery.

Symptoms

Common symptoms

• Feeling very tired and weak
• Pale or yellowish skin
• Shortness of breath, even with mild activity
• Dizziness or lightheadedness
• Heart palpitations (feeling like your heart is racing or skipping beats)
• Numbness or tingling in your hands and feet
• Difficulty walking or balance problems
• Memory loss, confusion, or trouble thinking clearly

Symptoms in children

• Delayed development or slow growth
• Irritability and fussiness
• Failure to thrive (not gaining weight or growing as expected)
• Pale skin and tiredness

Symptoms in older adults

• Confusion or memory problems that may look like dementia
• Numbness or tingling in the arms and legs
• Loss of balance and unsteady walking
• Fatigue and weakness that gets worse over time

Causes

Main causes

• Not getting enough vitamin B12 from your diet, especially common in vegans and strict vegetarians
• Pernicious anemia, an autoimmune condition where your body attacks the cells in your stomach that help you absorb B12
• Conditions that affect the stomach or intestines, such as Crohn's disease, celiac disease, or having part of your stomach or intestine removed
• Long-term use of certain medications, like metformin for diabetes or proton pump inhibitors for acid reflux

Risk factors

• Being over 60 years old
• Following a vegan or strict vegetarian diet without B12 supplements
• Having a gastrointestinal disorder like Crohn's disease or celiac disease
• Having had stomach or intestinal surgery
• Having a family history of pernicious anemia
• Long-term use of medications that reduce stomach acid or affect B12 absorption

When to see a doctor

See a doctor urgently if:

• If you have severe shortness of breath, chest pain, sudden confusion, or severe weakness, call your local emergency number immediately.
• If you have new numbness or tingling in your hands or feet that is getting worse, see a doctor the same day.

Book a routine appointment if:

• If you have persistent tiredness, mild shortness of breath, or other symptoms that don't go away, make an appointment with your doctor.
• If you are at risk for B12 deficiency (for example, if you are vegan or have a digestive condition), talk to your doctor about checking your B12 levels.

Diagnosis

Your doctor will ask about your symptoms, diet, medical history, and any medications you take. They will also do a physical exam and order blood tests to check your red blood cells and B12 levels.

Tests that may be done

• Complete blood count to check for anemia
• Vitamin B12 level in your blood
• Methylmalonic acid test (a more sensitive test for early B12 deficiency)
• Homocysteine level test (another marker for B12 deficiency)
• Intrinsic factor antibody test to check for pernicious anemia

What to expect at your appointment

The blood tests are simple and quick. Your doctor may need to repeat them after treatment to make sure your B12 levels are normal. You may also be referred to a specialist if the cause is not clear.

Treatment

Treatment for B12 deficiency anemia focuses on replacing the missing vitamin B12 and addressing the underlying cause. Most people need lifelong treatment if the deficiency is due to absorption problems. With treatment, symptoms usually improve within a few weeks.

Self-care at home

• Eat a balanced diet that includes foods rich in B12, such as meat, fish, eggs, dairy, or fortified foods (like some breakfast cereals).
• If you are vegan or vegetarian, talk to your doctor or dietitian about the best way to get enough B12 (fortified foods or supplements).
• Take any supplements your doctor recommends exactly as directed.

Medical treatments

Treatment usually involves vitamin B12 replacement. This may be given as injections (shots) into a muscle, often every other day for a short time, then less often. For some people, high-dose oral B12 tablets may work if the deficiency is mild or due to diet. The choice depends on the cause and severity. Your doctor will decide what is best for you.

When is surgery considered?

Surgery is not typically needed for B12 deficiency anemia itself. In rare cases, surgery may be needed to treat an underlying condition that is causing the deficiency, such as removing a part of the intestine that is damaged.

Living with this condition

Most people with B12 deficiency anemia need ongoing treatment, such as regular B12 injections or tablets. You'll need to have your B12 levels checked periodically and follow up with your doctor.

Lifestyle tips

• Get regular check-ups to monitor your B12 levels.
• Avoid smoking and limit alcohol, as they can worsen anemia.
• Manage stress with relaxation techniques or gentle exercise.
• Keep a record of your symptoms to share with your doctor.

Diet and exercise

Eat a balanced diet that includes B12-rich foods. If you have pernicious anemia or absorption problems, diet alone may not be enough, but it is still important for overall health. Gentle exercise, like walking or stretching, can help improve energy levels. Start slowly and listen to your body.

Mental health and emotional wellbeing

Living with a chronic condition like B12 deficiency anemia can be frustrating. Fatigue, memory problems, and other symptoms can affect your mood and mental health. If you feel anxious, sad, or overwhelmed, talk to your doctor. They can connect you with a counselor or support group. Remember, you are not alone. If you are having thoughts of harming yourself, call your local crisis helpline or emergency number.

Prevention

In some cases, yes. If you follow a vegan or vegetarian diet, you can prevent B12 deficiency by eating fortified foods or taking B12 supplements. However, pernicious anemia and other absorption problems cannot be prevented; they need to be treated once they occur.

Screening programmes

Routine screening for B12 deficiency is not recommended for the general population. Your doctor may recommend a B12 test if you have risk factors, such as being older, having a digestive condition, or following a vegan diet.

Complications

If left untreated

• Permanent nerve damage, including numbness, weakness, and trouble walking
• Heart problems, such as an enlarged heart or heart failure
• Pregnancy complications, including neural tube defects in the baby
• Confusion, memory loss, and other cognitive issues that may become irreversible

Long-term outlook

With proper treatment, the outlook is very good. Most people experience significant improvement in symptoms within a few weeks. For most, the condition can be managed effectively with B12 replacement, allowing them to lead a normal, healthy life.

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