In my practice I use different forms of Vitamin B12. In this article I explain some of the differences between cyanocobalamin, methylcobalamin, and hydroxocobalamin.
Cyanocobalamin can be given as an intramuscular injection. It should not be given intravenously. However, after injection it will need to convert to methylcobalamin, and then to hydroxocobalamin to be used by the body. Of all the forms of Vitamin B12 it is the least painful for the patient to inject. After introduction into the body it provides a small amount of cyanide. For individuals who are overall very healthy this is a good choice and this is also the least expensive form of injectable Vitamin B12. It is known that some people, such as smokers, are less able to transform cyanocobalamin into methylcobalamin due to toxins and heavy metals in the liver. These individuals need to use other forms of Vitamin B12.
Methylcobalamin is more bioactive and can be given intramuscularly, intravenously, and intraarticularly. It is slightly painful to inject into the muscle. In my practice I also use methylcobalamin when I do Prolozone injections into joints and into subcutaneously (under the skin). This is also a better choice for smokers who are unable to convert cyanocobalamin into methylcobalamin.
Hydroxocobalamin is the most bioactive form of Vitamin B12 and mostly given intravenously as intramuscular injections are very painful. If given intramuscularly it is mixed the local anesthetic procaine. Hydroxocobalamin is retained longer in the body and can be dosed less frequently. An additional application of hydroxocobalamin is that it can be used for patients with cyanide poisoning as it binds cyanide and allows for elimination through the kidneys.