Vitamin deficiency anemia

A lack of folate and vitamin B-12 can cause red blood cells to become too large so they can't carry oxygen well.

Update Date: 16.09.2025

Overview
Symptoms
Causes
Risk factors
Complications
Prevention
Diagnosis
Treatment
Preparing for your appointment
Overview
Symptoms
Causes
Risk factors
Complications
Prevention
Diagnosis
Treatment
Preparing for your appointment

Overview

Vitamin deficiency anemia is having too few healthy red blood cells. It happens when the body has too little vitamin B-12 and folate.

Not eating enough foods that have vitamin B-12 and folate can cause vitamin deficiency anemia. Or the body might have trouble taking in and using these vitamins.

Without these nutrients, the body makes red blood cells that are too large and don't work well. So the cells are less able to carry oxygen throughout the body.

Symptoms can include tiredness, shortness of breath and being dizzy. Vitamin supplements, taken by pill or in a shot, can fix the condition.

Symptoms

Vitamin B-12 deficiency anemia most often begins slowly over months to years. You may not notice symptoms at first. But symptoms most often get worse as the deficiency worsens. Folate deficiency symptoms can start within weeks.

Symptoms may include:

  • Tiredness.
  • Shortness of breath.
  • Feeling dizzy.
  • Pale or yellow skin. This may be harder to see on Black or brown skin.
  • Heartbeats that aren't regular.
  • Weight loss.
  • Numbness or tingling in the hands and feet.
  • Muscle weakness.
  • Changes in thinking or behaving.
  • Movements that aren't steady.

Causes

Vitamin deficiency anemia can happen from not eating enough foods that have vitamin B-12 and folate, or from the body having trouble taking in and using these vitamins.

Vitamin B-12 deficiency

The following can cause low levels of vitamin B-12:

  • Pernicious anemia. With this condition, the body's immune system attacks cells in the stomach that make a substance called intrinsic factor. Without this substance, the intestines can't take in B-12.
  • Gastric surgeries. Having surgery that removes parts of the stomach or intestines can lessen the amount of intrinsic factor the body makes and lessen the area the body has to take in vitamin B-12.
  • Intestinal conditions. Crohn's disease and celiac disease can keep the body from taking in vitamin B-12. So can tapeworms. Eating tainted fish can cause tapeworms.
  • Diet. Vitamin B-12 is mainly in meat, eggs and milk. So people who don't eat these foods may need to take B-12 supplements. But diet isn't often the cause of vitamin B-12 deficiency.

Folate deficiency

Also known as vitamin B-9, folate is mainly in dark green leafy vegetables and liver. A folate deficiency can happen when people don't eat foods that have folate, or their bodies can't take in folate from food.

The following can cause low levels of folate:

  • Conditions of the intestines, such as celiac disease.
  • Surgical removal or bypass of a large part of the intestines.
  • Drinking a lot of alcohol.
  • A diet low in folate.
  • Prescription medicines, such as some antiseizure medicines.

People who are pregnant or breastfeeding have a greater need for folate. So do people who get dialysis for kidney disease.

Not enough folate can cause birth issues during pregnancy. But folate deficiency is less common in countries where food makers add folate to food products such as breads, cereals and pasta.

Risk factors

The following may increase the risk of vitamin deficiency anemia:

  • Certain autoimmune diseases, including Crohn's disease, celiac disease and type 1 diabetes.
  • Surgery to remove part of the stomach or intestines.
  • Older age.
  • Long-term alcohol use.

Complications

Not having enough vitamin B-12 or folate raises the risk of many health concerns, including:

  • Pregnancy complications. An unborn baby, also called a fetus, who doesn't get enough folate during pregnancy can have brain and spinal cord conditions present at birth.
  • Nervous system conditions. People need vitamin B-12 for the brain to work well. If not treated, vitamin B-12 deficiency can lead to issues with the nerves, brain or spinal cord. These might include lasting tingling in the hands and feet or trouble with balance.
  • Cancer. Pernicious anemia raises the risk of stomach or intestinal cancer.

Prevention

You can prevent some forms of vitamin deficiency anemia by choosing a healthy diet that includes a wide range of foods.

Foods rich in vitamin B-12 include:

  • Beef, liver, chicken and fish.
  • Eggs.
  • Foods with vitamin B-12 added, called fortified. These include many breakfast cereals.
  • Milk, cheese and yogurt.

Foods rich in folate include:

  • Broccoli, spinach, asparagus and lima beans.
  • Oranges, lemons, bananas, strawberries and melons.
  • Enriched grain products, such as bread, cereal, pasta and rice.
  • Liver, kidney, yeast, mushrooms and peanuts.

Most adults need these daily dietary amounts of the following vitamins:

  • Vitamin B-12, 2.4 micrograms (mcg).
  • Folate or folic acid, 400 mcg.

People who are pregnant or breastfeeding may need more of each vitamin.

Most people get enough vitamins from the foods they eat. But if you limit what you eat or you've had gastric bypass surgery, you may want to take a multivitamin.

Diagnosis

To help diagnose vitamin deficiency anemia, you might have blood tests that check for:

  • The number and look of red blood cells.
  • The amount of vitamin B-12 and folate in the blood.
  • Antibodies to intrinsic factor, which means pernicious anemia. Antibodies are proteins the immune system makes to fight off invaders.

Treatment

Treatment for vitamin deficiency anemia involves taking the vitamin you don't have enough of. For pernicious anemia, you most often get vitamin B-12 in a shot. You may need to keep getting the shot for the rest of your life.

Vitamin B-12 comes as:

  • Shots into a muscle or under the skin.
  • Pills taken by mouth.
  • A liquid or tablet that dissolves under the tongue.
  • Nose gel or sprays.

Medicines to boost folate levels most often come as pills to take by mouth. But some people get folic acid through a tube into a vein.

Preparing for your appointment

Start by seeing your main healthcare professional, who may send you to a specialist in blood conditions, called a hematologist.

Here's some information to help you get ready for your appointment.

What you can do

Make a list of:

  • Your symptoms and when they began.
  • Key medical information, including other conditions you have.
  • All medicines, vitamins and supplements you take, including dosages.
  • Questions to ask your healthcare professional.

For vitamin deficiency anemia, basic questions to ask include:

  • What's the most likely cause of my symptoms?
  • What else could cause my symptoms?
  • Is my condition likely to go away or to last?
  • What treatment do you suggest?
  • I have another health condition. How can I best manage these conditions together?
  • What foods do I need to add to my diet?
  • Where can I find more information about vitamin deficiency anemia?

Be sure to ask all the questions you have.

What to expect from your doctor

Your healthcare professional may ask you questions, such as:

  • How bad are your symptoms?
  • Does anything seem to make your symptoms better?
  • Does anything seem to make your symptoms worse?
  • Are you a vegetarian or a vegan?
  • Do you drink alcohol? If so, how often, and how many drinks do you have?
  • Do you use tobacco products?

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