Vitamin B-12 is a lot like a key, opening up doorways that lead to an array of metabolic, cellular processes. Like a key, vitamin B-12 is unique among all other vitamins in both structure and function. Plants, animals, and fungi do not create it, unlike most dietary nutrients. While bacteria in the gut can create B-12, it is unproven as to whether or not the production is adequate. Without this important nutrient, cellular function would cease and energy would plummet. Considering that B-12 contributes to the production of ATP, many people with low energy levels will often get vitamin B-12 injections. Vitamin B-12 deficiency is common among both vegans and meat eaters alike, and more people today are reaching for supplementation.
Health Benefits of Vitamin B-12
This essential nutrient, mostly available from animal sources, protects nerve and brain cells from free radical damage. B-12 has also been shown to reduce pain associated with neuropathy.  The vitamin contributes to the creation of healthy DNA and RNA (the human body’s genetic material). It also works with other B vitamins to form red blood cells, support immune system health, improve mood, protect the cardiovascular system, and maintain overall energy levels.
The only natural sources of B-12 are animal foods. This includes organ meats (liver and kidney), eggs, beef, pork, seafood, and dairy products. These foods, however, often carry a heavy toxic burden, so supplementation with a vegan B-12 supplement is often advised for most people. While vegetarians can get vitamin B-12 through dairy, vegans need to supplement so as not to become deficient. Early symptoms of B-12 deficiency include fatigue, digestive problems, nausea, and loss of menstruation. Advanced symptoms include nerve pain, mental health disorders, infertility, impaired immune function, and anemia.
What are the 4 Types of B-12?
Everyone should understand the importance of getting enough B-12 in the diet, something that is usually easier said than done. Some estimates show up to 40% of the US population suffer from some form of B-12 deficiency. That’s almost half of the population! Knowing the four different types of B-12 will allow you to choose the right one for you.
This is the most active form in the human body. It converts homocysteine into methionine, which helps protect the cardiovascular system. Methylcobalamin also offers overall protection to the nervous system. This B-12 form can also cross the blood-brain barrier–without assistance–to protect brain cells. It contributes essential methyl groups needed for detoxification and to start the body’s biochemical reactions.
This synthetic version of vitamin B-12 is created in a lab, which makes it the cheapest supplement option. It offers the most stable form of B-12, although it does so through the presence of a cyanide molecule. While the amount of cyanide is not dangerous, it does require the body to expend energy to convert and remove it.
Bacteria naturally creates this form of vitamin B-12, making it the main type found in most foods. It easily converts into methylcobalamin in the body. Hydroxocobalamin is commonly used via injection as a treatment for B-12 deficiency as well as a treatment for cyanide poisoning.
The energy formation that occurs during the Citric Acid cycle requires this form of B-12. Although naturally occurring, it is the least stable of the four types of B-12 outside the human body and does not translate well into a tablet-based supplement. It can be difficult to find this one in supplement form, although some supplements, like Vegansafe™, have been able to stabilize it.
B-12 Absorption Rates Differ by B-12 Type
It’s conservatively estimated that at least 40% of Americans have trouble absorbing B-12. Whereas the human body is able to easily absorb most other vitamins, B-12 absorption is especially reliant on digestive health.
Your stomach produces, or at least is supposed to produce, a protein to help with B-12 absorption; that protein is called intrinsic factor. Not having enough intrinsic factor is the most common reason for not absorbing enough B-12.
There are a few reasons a person might not have enough intrinsic factor — surgery, gastritis, consuming food preservatives like MSG, exposure to mercury, intestinal ailments like leaky gut, gluten sensitivity, pernicious anemia, and weak stomach acid. Sometimes your body just doesn’t produce enough. Regardless, without intrinsic factor, it’s hard for your body to absorb the B-12 it needs and B-12 deficiency becomes a real risk.
Because of the inherent potential for B-12 absorption problems, there’s absolutely no reason to mess around with anything other than the most absorbable types of B-12. According to the National Institute of Health, a combination of methylcobalamin and adenosylcobalamin is the most absorbable and bioavailable supplemental B-12 and superior to formulations that only contain cobalamin or hydroxocobalamin. 
One Final Thought
When it comes to supplementing with vitamin B-12, methylcobalamin offers the best option. Like hydroxocobalamin and adenosylcobalamin, it contains molecules the body can use, as opposed to cyanocobalamin which takes a methyl group and forces the liver to dispose of the cyanide molecule. This makes methylcobalamin ideal for anyone looking to take B-12 for a natural energy boost.
The good news is that all forms of B-12 have no known adverse side effects. For anyone with a B-12 deficiency, or for those who have adopted vegan diets, I recommend Vegansafe™ B-12 as a highly-bioavailable and vegan-friendly option.
Do you take B-12 supplements? Which one? Share your comments with us below!
Watch an In-Depth Video on
Everything You Need to Know About Vitamin B-12
Video Length: 60 minutes
by Dr. Edward Group DC, NP, DACBN, DCBCN, DABFM
- Shibuya K1, Misawa S, Nasu S, et al. Safety and efficacy of intravenous ultra-high dose methylcobalamin treatment for peripheral neuropathy: a phase I/II open label clinical trial. Intern Med. 2014;53(17):1927-31.
- National Institute of Health. Vitamin B12 Dietary Supplement Fact Sheet.