Vitamin B12 is one of the most commonly asked about vitamins. It is also one of the most misunderstood vitamins. B12 has some unique aspects that make it different than most other vitamins and minerals. In this week’s article we will look at determining if a person needs to supplement with B12 and what that right dose of B12 would be.
Vitamin B12 has many roles in the body. It’s most well-known roles are in the production of energy, blood cell generation, functioning of the brain, and as a methyl donator in the nervous system. B12 deficiency puts a person at risk of a variety of symptoms affecting the neurological system, blood cell formation, and energy production. The most well-known disease of B12 deficiency is pernicious anemia. This is where there’s a problem in the stomach, resulting in the inability to absorb enough B12.
Identifying overt vitamin B12 deficiency usually is straight forward. However, identifying sub-optimal or sub-clinical B12 deficiency can be controversial and difficult. For the most part, I utilize three types of tests to determine if someone has a B12 problem. None of the measures is exact, but I believe they are useful in identifying a problem.
The first two tests I look at can be run as part of your basic blood work. A marker called Vitamin B12 Status can be run to tell you how much B12 was available in the blood sample. This test picks up major deficiencies but may not pick up sub-clinical problems. One problem with this test is that the normal range in BC is likely set too low, which can make it look like a person does not have a B12 deficiency. I always get suspicious is the B12 Status is below 300-450.
The second test I look at is almost always part of your basic blood work. It’s called MCH, which stands for mean corpuscular haemoglobin. This test essentially looks at the red blood cells to see if they are enlarging in a suspicious way. When B12 is deficient, our red blood cells have difficulty maintaining their proper size and physical characteristics. Instead of getting smaller, like in iron deficiency, the RBCs get larger and lighter. I get suspicious anytime MCH gets about 31.
The third test I look at is a test by trial. This is where we give a patient 1-3 B12 shots to see how they respond. If they feel better with B12 shots, it’s likely they had a sub-clinical deficiency. I meet many patients who have figured out previously that they simply function better when they get regular B12 shots.
Not all B12 is equal. There are three major types of B12 you can purchase in supplement or injectable form. The three types are hydroxycobalamin, cyanocobalamin, and methylcobalamin. For the most part, I believe methylcobalamin to be the best because the methyl component plays a major role in neurological function.