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Vitamin B12 Deficiency: Causes, Symptoms and Treatment

The information provided herein does not constitute an expert or medical advice, nor intended to replace such advice.

Sexual Health

You’ve probably heard that vitamin B12 is very important for your body to produce red blood cells and prevent anemia. And while that’s true, vitamin B12 actually plays other significant roles in human health.

The effects of low vitamin B12 on your health can lead to disease, and it’s helpful to learn how to recognize B12 deficiency symptoms so you know when it’s time to seek medical assistance or get tested.

What is vitamin B12?

Vitamin B12 is a water-soluble vitamin. According to the Cleveland Clinic, your body uses hydrochloric acid in your stomach to remove vitamin B12 from the food it was bound to. Afterwards, vitamin B12 combines with a compound called intrinsic factor, which is made in your stomach. Intrinsic factor is essential for vitamin B12 to be absorbed properly. Then, vitamin B12 can be absorbed by your small intestine.

Vitamin B12 is present in different food sources, including:

  • Dairy products
  • Fortified cereals
  • Eggs
  • Salmon
  • Fortified plant-based milks
  • Tuna
  • Beef
  • Liver
  • Kidneys
  • Clams
  • Fortified cereals

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What causes vitamin B12 deficiency?

Some people don’t produce enough intrinsic factor, which doesn’t allow their bodies to absorb vitamin B12 properly, leading to a deficiency. This results in a condition called pernicious anemia or B12 deficiency anemia.

Another one of the causes of B12 deficiency can be an insufficient intake. Vitamin B12 can be found mostly in animal products, such as meat, fish, poultry, and dairy. Although some cereals and breads are fortified with vitamin B12, this amount may not be enough to prevent vitamin B12 deficiency signs in people who follow a vegan or vegetarian diet.

Other reasons for B12 deficiency include older age and gastrointestinal malabsorption disorders, such as Crohn’s disease. Past gastric surgeries could also act as B12 deficiency causes, especially if a large amount of gastric tissue was removed during the procedure. In these cases, patients may suffer from several micronutrient deficiencies at once.

Symptoms of vitamin B12 deficiency

The signs of low vitamin B12 can be varied, and some people may not even realize that they have a deficiency for a long time. According to the NHS, signs of low vitamin B12 can include:

  • Fatigue
  • Muscular weakness
  • Feeling pins and needles in your limbs (paresthesia)
  • Sore and red tongue
  • Vision problems
  • Oral ulcers
  • Pale or yellowish skin
  • Pale gums and mucous membranes
  • Memory and concentration problems
  • Heart palpitations
  • Rapid heartbeat
  • Depression
  • Confusion

Low B12 in men can also result in erectile dysfunction, while female low B12 symptoms may include temporary infertility.

B12 deficiency signs can be similar to the symptoms of other types of anemia. Alternatively, you can experience these symptoms if you have a vitamin B12 deficiency but haven’t developed anemia as a result yet.

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Side effects of vitamin B12 deficiency

The long term effects of vitamin B12 deficiency can be life-threatening if the condition isn’t treated properly. It can take several years for the manifestations of B12 deficiency to become apparent, which can make it difficult to diagnose it early on.

If left untreated, severe cases of vitamin B12 deficiency anemia can lead to neurological problems and even death. And while the deficiency can be successfully treated and most symptoms will typically be reversed, the condition can lead to permanent health issues in some cases.

According to StatPearls, some of the complications that can result from vitamin B12 deficiency include:

  • Heart failure
  • Severe and incapacitating neurological deficits
  • Increased risk of gastric cancer
  • Increased risk of autoimmune disorders, such as type 1 diabetes, Hashimoto disease, and rheumatoid arthritis

How do you know if you’re B12 deficient?

If you’re showing signs of vitamin B12 deficiency, you may need to get a vitamin B12 level test done. According to MedlinePlus, this is a simple blood test, but you may need to fast for a few hours before having your sample collected. Additionally, you may need to stop taking certain medications before the test.

Your doctor could order additional tests if they suspect a B12 deficiency, since they may need to rule out other underlying conditions that are causing your low B12.

Vitamin B12 deficiency anemia causes your body to produce abnormally large red blood cells, which are unable to carry oxygen efficiently. These red blood cells can be seen in a complete blood count (CBC) and blood smear, which analyzes all the types of cells in your blood. This test is typically ordered by a healthcare professional and requires a venous blood sample.

But now, you can also get a home vitamin B12 test to monitor your levels. These tests require a fingerprick sample; depending on the provider, you’ll simply have to mail your sample back or take it to a lab yourself.

Treatment for vitamin B12 deficiency

The standard of treatment for a lack of vitamin B12 is to increase your intake of this vitamin, whether it’s through natural food sources or supplements.

Depending on the cause of the deficiency, you may need to take daily supplements or have regular B12 injections. People who follow a vegetarian or vegan diet often require B12 supplements to increase their intake.

Most cases of vitamin B12 deficiency respond very well to this treatment; however, nerve damage caused by this condition can become permanent in some cases.


Vitamin B12 Deficiency - my.clevelandclinic.org

Vitamin B12 Benefits and Best Sources - health.clevelandclinic.org

Vitamin B12 or folate deficiency anaemia - nhs.uk

Vitamin B12 Deficiency - ncbi.nlm.nih.gov

Vitamin B12 level - medlineplus.gov

Dr. Andrea Pinto Lopez

Dr. Andrea Pinto Lopez

Dec 02, 2022

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