You can find B12 in four chemical compounds: methylcobalamin, hydroxocobalamin, adenosylcobalamin and cyanocobalamin. Methylcobalamin and adenosylcobalamin are in meat and dairy products.

[41] In healthy volunteers, the use of hydroxocobalamin has been linked to chromaturia, dose-dependent erythema, headache, GI distress, pruritus, dysphagia, and infusion-site reactions. Allergic ...

There are several types of vitamin B12, including cyanocobalamin, methylcobalamin, and hydroxocobalamin. Cyanocobalamin is the most commonly used type in supplements, but some people may prefer ...