Vitamin B12 is a lot like a key, opening up doorways that lead to an array of metabolic, cellular processes. Like a key, vitamin B12 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 B12, the production is inadequate.
Without this important nutrient, cellular function would cease, and our energy would plummet. Considering that B12 contributes to the production of ATP — the molecule that provides energy to every cell — many people with low energy levels get vitamin B12 injections. Vitamin B12 deficiency is common among both vegans and meat-eaters alike, and more people today are opting for supplementation.
Health Benefits of Vitamin B12
This essential nutrient, mostly available from animal sources, protects nerve and brain cells from free radical damage. B12 has also been shown to reduce discomfort 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 B12 are animal foods. These foods, however, often carry a heavy toxic burden, so supplementation with a vegan B12 supplement is often advised for most people. While vegetarians can get vitamin B12 through dairy, vegans must supplement so as not to become deficient. Early symptoms of B12 deficiency include fatigue, digestive issues, 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 B12?
Everyone should understand the importance of getting enough B12 in the diet, something that is usually easier said than done. Some estimates show up to 40 percent 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 B12 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 B12 form can also cross the blood-brain barrier — without assistance — to protect brain cells. It contributes essential methyl groups required for detoxification and to start the body’s biochemical reactions.
This synthetic version of vitamin B12 is created in a lab, which makes it the cheapest supplement option. It offers the most stable form of B12, 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 B12, 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 B12 deficiency as well as a treatment for cyanide poisoning.
The energy formation that occurs during the Citric Acid Cycle requires this form of B12. Although naturally occurring, it is the least stable of the four types of B12 outside the human body and does not translate well into a tablet-based supplement. It can be difficult to find this one in a supplement, although some, like Global Healing's B12 Blend, have created a stable form of the molecule.
B-12 Absorption Rates Differ by B12 Type
It’s conservatively estimated that at least 40 percent of Americans have trouble absorbing B12. Whereas the human body is able to easily absorb most other vitamins, B12 absorption is especially reliant on digestive health.
Your stomach produces, or at least is supposed to produce, a protein to help with B12 absorption; that protein is called intrinsic factor. Not having enough intrinsic factor is the most common reason for not absorbing enough B12.
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 B12 it requires, and deficiency becomes a real risk.
Because of the inherent potential for B12 absorption issues, you should take the most absorbable types of B12.
Points to Remember
When it comes to supplementing with vitamin B12, 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 B12 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 B12 deficiency, or for those who have adopted vegan diets, I recommend B12 Blend. It provides a combination of methylcobalamin and adenosylcobalamin in a highly absorbable and bioavailable form.
If you're looking for a more advanced formula, B12 Tri-Blend contains methylcobalamin, adenosylcobalamin, and hydroxocobalamin, plus Energized Trace Minerals™ that gives it amplified bioavailability. It is great for athletes and people who require advanced nutritional support or detox.
Everything You Want to Know About Vitamin B12
Length: 50 minutes
- Shibuya K, 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.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.