Vitamin B12 Deficiency: Symptoms And Treatments

Vitamin B12: The Most Important Nutrient You Aren’t Thinking About.
Vitamin B12: The Most Important Nutrient You Aren’t Thinking About.

You might not be getting enough vitamin B12 and may, indeed, not even be thinking of it. One reason you aren’t thinking about it may be because we tend to fall in (and out of!) love with one nutrient at a time (such as vitamin C, beta carotene, lycopene, and so on) and vitamin B12 isn’t the nutrient du jour.

But another main reason you may not be thinking about it is because you can’t! Vitamin B12 deficiency can limit your ability to think clearly about anything!


Why Is Vitamin B12 Essential?

Like all vitamins, B12 is an organic compound, made of carbons (as opposed to minerals, which are inorganic), that is essential for our normal metabolic function and health. Also, like most vitamins, B12 plays a variety of roles in our metabolism.

  1. It is essential for the manufacture of red blood cells; a deficiency of this leads to a type of anemia.
  2. It supports the normal functioning of nerve cells and manufactures myelin, the insulating material that surrounds some of our nerve cells and speeds neural transmission.
  3. It is required for the replication of DNA.

[pullquote]Vitamin B12 deficiency can mimic all signs of aging.[/pullquote]


Although each of these uses is important, note the last one in particular. With B12 deficiency, our DNA cannot replicate normally – meaning we can’t generate new, healthy cells.

Symptoms Of Vitamin B12 Deficiency

Common symptoms of vitamin B12 deficiency include weakness, numbness and tingling, fatigue, dizziness, swelling and irritation of the mouth and tongue, and irritability.


Although anemia can develop, it can be prevented with a high intake of folate, which compensates for the deficiency.

[pullquote]The most serious manifestation of B12 deficiency is impaired brain function due to the effect of B12 on nerve cells.[/pullquote]


Advanced B12 deficiency causes dementia severe enough to resemble Alzheimer’s disease. But generally, the dementia caused by the deficiency is completely reversible with supplementation. While folate can prevent anemia, it cannot prevent dementia – only B12 itself can do the job.

Difficulties With Vitamin B12 Absorption

B12 is found in animal foods (and fortified cereals), so vegans are vulnerable to this deficiency. But the most important cause has to do with the unique way B12 is absorbed.


To get into the bloodstream, B12 must be escorted by a protein called intrinsic factor, produced by the stomach cells. Many disorders of the stomach, such as gastritis, particularly common after age 50, can interfere with the production of the intrinsic factor. This condition is called pernicious anemia.

Medications that affect the stomach – such as aspirin, antacids, and proton-pump inhibitors – and the commonly used diabetes medication metformin (Glucophage) can also interfere with the intrinsic factor production and result in B12 deficiency.


Treatment Options

  • For a garden-variety B12 deficiency, due to inadequate food or supplement intake, oral supplementation can fix the problem.
  • Pernicious anemia cannot be treated with oral B12, because of the lack of the intrinsic factor that prevents absorption. The appropriate treatment is vitamin B12 injections.
  • In some cases, genetic mutations can also limit the ability to metabolize B12. Here, you will need to get the active form, called methylcobalamin, instead of the more common cyanocobalamin.

Health-care professionals are, of course, taught to be on the lookout for B12 deficiency, particularly in patients over 50 years of age with suggestive symptoms. But healthcare is at its best when both the doctor and the patient are on the ball!

I encourage an empowered, assertive role for all patients. So if you are at all concerned about the possibility of B12 deficiency, just ask before you forget the question!