Vitamin B12

Two general principles encourage taking B12 supplements. One is that if you are reducing meat consumption (or even going vegan) you will not be getting B12. In our society, meat (or other animal products, such as eggs) is the only significant source of B12. The second is that a persons ability to absorb B12 is reduced as a person becomes old.

B12 is actually produced by microorganisms. The usual pathway to get it though is from meat. If you lived in a 3rd world country with plenty of microorganisms in your environment and water, you might not need to consume meat.

I passed 70 some time ago, and I am reducing my meat intake as part of an effort to lower cholesterol levels. So both principles just mentioned clearly apply. Also my blood work shows reduced blood cell counts (both red and white) which can indicate a need to take B12. My guess is that I have been borderline with regard to B12 for some time.

The pills are cheap. I can get a years supply of 1000 mcg pills for under $20. You will read that the daily requirement for B12 is 2.4 mcg (micrograms) per day. For people over 50, 10 mcg is recommended.

So why take a 1000 mcg pill? First of all, it is harmless as B12 is a water soluble vitamin and your body just takes what it needs. Second is that if you go to the drugstore, the lowest available dose is 1000 mcg. Third is that you body only absorbs a small fraction of what is in your diet, so more is good.

It was off to the local drugstore to buy a bottle of B12 (methylcobalamin) pills. I bought the 1000 mcg version and figured to take two per day for the first few days.

A 1000 mcg pill probably sounds like massive overkill. Remember that B12 is water soluble and any excess will be gotten rid of in urine, so taking too much is harmless.

On page 408 of Dr. Greger's book, he recommends 2500 mcg per week for people over age 65 who eat a plant based diet, and perhaps as much as 1000 mcg per day for those people.

Background information

I read a chapter in a book I have ("How not to die" by Dr. Greger) and he mentions that you absolutely need to take B12 supplements if you embark on a regime that resembles a vegan diet. And he mentions dire consequences if you don't. (Including things as severe as paralysis and blindness).

He says it may take years before problems manifest themselves.

I was reading about peripheral neuropathy, then decided to do a search about B12 and neurological symptoms. I found statements like these:

Vitamin B12 deficiency can lead to nerve damage, causing symptoms like numbness, tingling, and even more severe neurological problems. This damage occurs because B12 is crucial for maintaining myelin, the protective sheath around nerves, which is essential for proper nerve function. Without sufficient B12, myelin can deteriorate, leading to nerve damage and impaired nerve signals.

Vitamin B12 deficiency is linked to impaired cognition and memory along with a sensation of tingling and numbness, an outcome of poor myelination.

Vitamin B12 deficiency can lead to memory loss and other cognitive problems, as B12 is crucial for nerve and brain health. Low B12 levels can be associated with memory issues, including impaired cognition and even dementia-like symptoms.

I also read that as people age (I am 70+ years old now) they often have trouble assimilating B12. Some people are missing something they call "intrinsic factor" that enables them to absorb B12 in their diet. When a B12 deficiency is due to a lack of "intrinsic factor" it produces what is called "pernicious anemia." This is yet another autoimmune condition caused by the body attacking the cells in the stomach lining that produce "intrinsic factor" and now we have a low red blood cell count in addition to nerve damage.

• B12 deficiency can be sneaky