We’ve already talked a lot about the benefits of vitamin B12 supplementation to those suffering from a B12 deficiency. But what does B12 do for your body in first place? Why is B12 good for you and is so crucial to have enough of?
Let’s dig into how vitamin B12 benefits you.
What Does Vitamin B12 Do to Our Body?
The health benefits of B12 to our system are huge. It is involved in:
- Formation of myelin, a fatty protective layer insulating your nerves. B12 is essential for the synthesis and repair of this sheath, which is wrapped around each and every nerve fiber in our body. Without B12, the myelin is gradually stripped off and nerves can’t transmit impulses and electrical signals properly. That’s how B12 deficient people get major nerve damage and strange sensations, sometimes ending up on a wheelchair. Think of your nerve system as a massive tangle of wires. Myelin insulates those wires so that they can conduct messages properly.
- Reducing homocysteine, an amino acid that — when high enough — is often associated with heart disease, cancer and most other modern diseases. Without vitamin B12, homocysteine can’t be converted into the form the body needs, so it starts accumulating in the blood.
- Replication of DNA. Using methylcobalamin — one of the two true B12 forms — the enzyme methionine synthase actually converts homocysteine into methionine for the purposes of DNA methylation. When you don’t have enough B12, your bone marrow won’t be able to make all the DNA that it needs for the production of white blood cells (cells that kill germs by launching immune responses against them), putting you at risk of developing infections.
- Cell and tissue growth. Cells characterized by rapid division (such as epithelial or myeloid cells, or bone marrow) appear to have the greatest need for B12, because each new cell needs its own DNA, which, as we just said, B12 helps synthesizing.
- Hormonal efficiency. Each and every cell in our body has a membrane, and it needs to be healthy so that hormones can enter to produce the effects they’re supposed to produce. That’s because those cell membranes have special receptors on them that allow our hormones to get in. Without B12’s stabilizing effect on the membranes, your hormones will just float around in your bloodstream until excreted.
- Production of red blood cells. Folate is needed for the synthesis of red blood cells (the tiny disc-shaped cells that deliver oxygen to every corner of your body), but vitamin B12 is required for a reaction that converts folate into a form the body can use to make those red blood cells. Without it, the body can’t access folate, and you get anemic. And when oxygen delivery is low, you become fatigued even with the slightest of effort.
- Proper metabolism. One of the pure forms of B12, adenosylcobalamin (also 5-deoxyadenosylcobalamin), is needed to convert L-methylmalonyl-CoA to citric acid cycle intermediate, succinyl-CoA, as part of metabolizing proteins and fats to extract energy from them.
- Preventing auto-immune diseases. When your immune system falsely recognizes parts of your own body as foreign, it launches vicious immune attacks on them. Normally, there are ‘markers’ attached to your cell membranes, telling your body it shouldn’t attacking them. But when B12 is lacking, those membranes may become unstable, which may jeopardize your immune system into attacking your own body.

How Do I Get Those Vitamin B12 Benefits?
Vitamin B12 is actually produced by the gut bacteria of animals that feed on the cobalt of the soil (that’s why B12’s name is cobalamin). Cows get it from devouring grass. We get it from devouring cows. It is the delicate cycle of life provided by Mother Nature. There is no life without death.
And so, to get the benefits of B12, all you’ll have to do is include vitamin B12 rich foods in your diet. Have a food-bound cobalamin malabsorption? You’ll have to supplement. If you can’t digest B12 at all through your stomach (pernicious anemia), you’ll need B12 injections for life. Any excess of B12 is excreted in the urine, so there’s no risk of B12 overdose.
What now?
Go get some steak and enjoy the benefits of vitamin B12.
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P.S. If you were looking for injections you can now get our B12 supplement, which can be easily converted into injections. This solves the recent issues with regulations taking many injection brands out of the market.
Very good article. To get the health benefits of vitamin b12 we don’t need a lot of it, about 40 to 50mcg per week.
Some doctors now are suggestting people over 50 should be taking at least 1000 mcg per day and if they have a big vitamin B12 deficiency they may need to take up to 15000 mcg for awhile then taper it off to 1000 mcg.
What is the max of B12 I can take without any side effects
I am taking 20,000 mcg a day, and by the way how many mcg make a mg
1,000mcg is 1mg. 20,000mcg is 20mg. B12 is non-toxic even in very high amounts. With shots, for example, any excess will be excreted in your urine within an hour.
I just turned 65 , have four stents and i need 10,000 mcg twice a day to get through the day. The lawn needs to be , food shopping etc .
Is this okay .
TIA
Bob,
From what I understand from Regev’s site here and a few others, this is not a high amount and there is no toxicity level. 10,000mcg = 10mg.
Some people take 1,000mg at a time, some take 10,000mg per day, and a few take even more along with folate. You are only taking 10mg so don’t worry, take what works for you.
Best wishes,
Molly
Any additional b12 vitamin benefits if my levels are already normal?
B12 is like fuel to a machine. “More” won’t make you run better. If your levels are normal (above 500, not the obsolete normal ranges used in many countries) and you show no symptoms, you don’t need to supplement.
Very nice post! My sister have deficiency and asked me what is vitamin b12 good for, very hapy I found this on Google. Thank you Sir.
My pleasure, Rameesha.
Awesome resource. What are the benefits of b12 vitamin when in methylcobalamin form as compared to cyanocobalamin?
Hi, I am from India , I am 33 female . I started vit b12 2500 mcg injection. my neurological symptoms gone away after 20 shots which were taken evey 4 days .after 20 shots dr. stopped my shots as only 7 were recomende. but after stoping shots my uneasyness in leg , muscle weakness got again back. but when i started taking shots again it vanished . so my first qustion is should i take more shots?. Here in India Doctor dont guide properly and are not concern that much due to rush of patients.
also my second question is my daughter who is age 5 shows same symptoms as brittle nails, tired ,cant run much, little dpression, uneasy feeling in head. I showed her to doctore they said kids are not allowed to give shots. so what u recommend .should i insist for shots for her and in what doses?
my email id is [email protected]
Pls help
It’s about time somneoe wrote about this.
I want to remove my stretch marks and spots on my body, could vitamin B12 help me on this issue?
What are your thoughts on Andenosylcobalamin injections that are offered for sale on a European pharmacy?
How is lack of vitamin b12 diagnosed?
Is having serious fatigue a sign you have it?
You can go to you doctor and have a physical & blood test. If you ever had nerve damage, or any type of nerve pain as in sciatic nerve pain then that is a great sign.
Found this: “B12 can protect against dementia, increase immune function, maintain nerves, and regenerate cells. B12 lowers homocysteine and protects against atherosclerosis. It’s necessary for maintaining methylation reactions that repair DNA and prevent cancer. “
this is a very good article.
I suffer from awful fatigue , my legs feel like lead so i have trouble walking some days, and ive got a continuous tingling in all my fingers 24/7.
Does this sound like Vit B12 deficiency,
Im 61 work as a community care worker and am up at 6. 5 mornings a week and i struggle to get through some days .,