Vitamin B-12 Level Test: Purpose, Procedure & Results

https://www.healthline.com/health/vitamin-b12-level

Vitamin B-12 Level Test: Purpose, Procedure & Results

What is a vitamin B-12 deficiency?
Vitamin B-12 is an important vitamin for many bodily functions, such as brain health, blood cell production, and proper nerve functioning. There are several ways to test your B-12 levels. You can get your blood drawn or take a home urine test. These tests will look at the levels of your:

• overall vitamin B-12
• methylmalonic acid (MMA)
• homocysteine
• holotranscobalamin (holoTC)
  
  

Research suggests that MMA and holoTC may be more accurate at reading low B-12 levels because they represent active B-12. 

When does your doctor order a vitamin B-12 test?

Your doctor might recommend a B-12 test if you have:

• tingling in the hands and feet
• problems with balance
• a racing heart
• confusion
• dementia
• weakness
• loss of appetite
  
  

You may also take this test if your doctor suspects you might have pernicious anemia. Pernicious anemia is a reduction in red blood cells. It occurs when your intestines can't absorb vitamin B-12, which is necessary for red blood cell production. Symptoms are not often seen in people younger than 30 years old. The average age of diagnosis is 60.

Symptoms of this condition include:

• diarrhea or constipation
• exhaustion
• loss of appetite

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