But a quick peek down the rabbit hole of this subject will reveal that there is a distinctively dark side to the industry, especially supplement companies owned by the world’s largest pharmaceutical giants like Bayer. If you want background on this subject, read my article, “Top Pharma-Brand of Children’s Vitamins Contains Aspartame, GMOs, & Other Hazardous Chemicals,” wherein we discuss the children’s “vitamin” known as Flinstones. It’s a train wreck of a story.

One ingredient I left out in that exposé was the form of B12 used in nearly all mass market vitamins, namely, cyanocobalamin. So, I want to dedicate some time to the topic here now. Mind you, it’s a highly controversial topic, as there are plenty of natural and/or integrative health consultants and professionals who do not agree with my view. And perhaps they are correct. That said, discussion and dialog on the topic is always healthy, and the perspective and research presented below may help counterbalance the topic with an appopriate dose of nuance, and perhaps some caution.

Cyanide-Based B12 Is the Most Common Form Used

Unknown to most consumers, cyanide is found in a wide range of vitamins and foods as a synthetic additive known as cyanocobalamin. Fortunately the cyanide has a very low potential to do harm because it is organically bound to cobalamin (vitamin B12)—that is, as long as everything is working correctly and that person hasn’t already been overburdened with environmental chemical exposures from cyanide, and related xenobiotic compounds that may interfere with their cyanide detoxifying pathways. Also, there are genetically-based differences in the ability of individuals to decyanate (remove the cyanide) cobalamin that has been identified to be mediated by a trafficking chaperone known as MMACHC. In fact, defects in MMACHC are believed to be the most common cause of inborn errors of B12 metabolism. Those who suffer from MMACHC-related dysfunctions should be careful to only use cyanide-free forms such as aquacobalamin, hydroxocobalamin, or methylcobalamin.

Cyanocobalamin is actually found in the vast majority of the vitamins on the market which contain B12, as it is relatively cheap (recovered from activated sewage sludge or mammalian tissue with the addition of potassium cyanide or produced through total chemical synthesis), and relatively stable (non-perishable). Despite its wide usage, it is not an ideal form of vitamin B12, as the cyanide must be removed from the cobalamin before it can perform its biological indispensable roles within the body. While there is plenty of research on the potential value of cyanide-bound vitamin B12, and certainly vitamin B deficiency can have devastating adverse health effects, but it does have potential to do harm, and at the very least cannot be considered superior to non-cyanide containing forms.

Is Cyanocobalamin Really a Health Concern?

In fact, when a person is poisoned with cyanide, as sometimes happens following smoke inhalation, and they are rushed to the emergency room, what do they give them to remove the cyanide? Hydroxocobalamin—a cyanide-free form of vitamin B12—which readily binds with the cyanide, becoming cyanocobalamin, which sequesters the cyanide, putting it into a less toxic form that can be more readily eliminated from the body via the lungs and kidneys. You can learn more about this cyanide detoxification approach on Emergency Physician Monthly’s site here.

Indeed, this is not the first time the question of the potential toxicity of cyanocobalamin has been raised. As far back as 1992, a report was published in Journal of the Royal Society of Medicine arguing for its withdrawal from use in vitamin therapy, especially with smokers experiencing neuropathy. Another study published in 1997 in the journal Blood, found that cyanocobalamin “antagonizes vitamin B12 in vitro and causes cell death from methionine deficiency.”

There are two recent studies comparing the effects of cyanocobalamin to methylcobalamin in inflammatory bowel disease, showing the cyanide-based form may aggravate symptoms of bowel inflammation by shifting the microbiota towards a more inflammatory profile.  This was demonstrated in both in an animal, and a human fecal sample, study.

Additional Ways to Obtain B12

There is an entirely different approach to maintaining adequate vitamin B12 levels, namely, through increasing populations of natural, vitamin B12-producing beneficial bacteria such as Lactobacillus reuteri. There has also been research showing that dietary contributions of B12 versus cyanocobalamin are far superior.