The four different forms of Vitamin B12

I’d like to talk a bit about one of my favorite B vitamins – B12. It is so important that without it cellular processes in our body would terminate and, if left untreated, lead to systemic failure. B12 is not a plant based vitamin, but it is created by bacteria in the guts of fish and animals. It is also produced in our own digestive system to a limited amount.

B12 is one of eight B vitamins. Though each is unique, they are commonly associated together because they tend to come from the same foods. Bs qualify as a vitamin as they are essential for life and our bodies cannot produce enough on their own. Vitamins by definition differ from minerals, essential fatty acids, and amino acids.

The list of Bs includes thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folic acid (B9) and various cobalamins (B12). There are various versions of some of these, such as niacinamide and nicotinamide riboside for B3.

Technically, B vitamins function as enzyme cofactors, and thus called coenzymes, or they are the precursors for them. Coenzymes help enzymes in our body do their work as catalysts in metabolism and detoxification. B vitamins are involved in producing red blood cells. They support synthesizing DNA during cell division and help us maintain good cognitive function, especially mood and energy.

Vitamins used to be available only through food and our own digestive process. It was not until the 1930s that we started extracting B vitamins from yeast and making them commercially available. Due to changes in soil, food processing, and diet, the amount we receive has been greatly altered. Thus practitioners today will recommend daily supplementation for some individuals.

The four distinct types of vitamin B12 are cyanocobalamin, hydroxocobalamin, methylcobalamin, and adenosylcobalamin.

Cyanocobalamin is the least expensive to produce and is commonly found in consumer multivitamins because it’s also stable. As an inactive form of B12, it does not occur naturally in any living organism and must be converted into another form that the body needs to function properly.

One problem is that about 40-60% of individuals are less likely to be able to convert cyanocobalamin into a more usable form, mythylcobalamin, due to mutations in their MTHFR genes.

Hydroxocobalamin is another inactive form of B12. Like cyanocobalamin, this form is less efficient as it also needs to be converted into an active form. It has some strengths in the body due to a longer half life, helping it stay in the blood stream longer.

You can find this in both injectible and sublingual forms through compounding pharmacies.

Adenosylcobalamin is considered an active form of B12 in the body. It is produced in the body through several processes starting when methylcobalamin converts homocysteine to methionine. It acts within the cell mitochondria as a building block for an enzyme that is part of a central metabolic cycle that produces energy – the Kreb’s cycle. It is not very stable in pill form, but you can find it in some liquid supplements.

Methylcobalamin gets my highest respect, though, as it doesn’t require conversion, like cyanocobalamin, and goes straight to work without any unnecessary energy expenditure. It is stable in capsule and sublingual form, but more expensive, and is used in most clinical grade supplements. Because it is in the active form, those of us with defects in the genes that control conversion are assured we are getting the right form.

Look at labels and they will show the form of vitamin B12 they are using. Stop on by if you’d like to talk more.

Scott Porter is a functional medicine pharmacist at Sandpoint Super Drug. He is a member of the Sandpoint Wellness Council.