Vitamin B12 Deficiency: Symptoms & Signs

Medically Reviewed on 9/10/2019

Vitamin B12 is a vitamin that is essential for many body functions, including the production of red blood cells. The body cannot make vitamin B12, and it needs to be supplied through the diet or by taking supplements. Vitamin B12 is found in foods of animal origin like meats, eggs, milk, and cheese. Vitamin B12 deficiency (cobalamin deficiency) is a condition that results when there is too little vitamin B12 in the body. Pernicious anemia is a kind of anemia that happens when the body is not able to absorb vitamin B12 through the digestive tract. A mild deficiency of vitamin B12 may not produce symptoms. Symptoms and signs, when they occur, can be similar to those of anemia, including

Other symptoms and signs include

  • digestive changes,
  • a smooth tongue, and
  • mental problems.

Causes of vitamin B12 deficiency

Consuming a strictly vegan diet without taking vitamin B12 supplements can cause vitamin B12 deficiency. Other causes include

Other vitamin b12 deficiency symptoms and signs


Next to red peppers, you can get the most vitamin C from ________________. See Answer

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.