Best form of B12 or combination
�Methylcobalamin supporters state its superiority as it is the primary circulatory form and acts as a methyl donor. Adenosylcobalamin, however, accounts for 70% of cobalamin stored in the liver�the major storage site for B12�while methylcobalamin accounts for only 1% to 3%. It is also argued that cyanocobalamin is poorly converted into its active forms and releases cyanide into circulation�neither of these statements is supported by research.
�Since the cyanocobalamin form of B-12 is deeply red colored, easy to crystallize, and is not sensitive to air-oxidation, it is typically used as a form of B-12 for food additives and in many common multivitamins. Research findings have demonstrated that oral cyanocobalamin is safe and easily and rapidly converted to both methylcobalamin and adenosylcobalamin during absorption and at the target cell, and does reverse B12 deficiency signs and symptoms.
�Oral cyanocobalamin has a long history of use worldwide. In Sweden, oral high-dose cyanocobalamin is the major treatment form for B12 deficiency and maintenance and has gained widespread popularity since its introduction in 1964. More than one million patients and years of data in Sweden support the use of oral cyanocobalamin to correct and prevent B12 deficiency signs and symptoms and it is considered a standard of care for most patients. In virtually every aspect of B12 activity oral cyanocobalamin has demonstrated benefits, including psychological, neurological, and hematological.
�A key function of B12 is its participation in methylation reactions. Foremost of these processes is the reduction of homocysteine. While methylcobalamin does participate in homocysteine reduction, it is secondary in significance to folic acid. Methylcobalamin receives its methyl group from folic acid (methyltetrahydrofolate). The body �recycles� methyl groups and cobalamin. In the homocysteine cycle, as an example, cobalamin donates its methyl group and is then converted back to methylcobalamin, receiving a methyl group from 5-methyl-tetrahydrofolate. The primary methyl donor is folic acid along with other methyl donors, whereas cyanocobalamin provides the vitamin B12 component for the cycle. In patients with end stage renal disease�a condition associated with hyperhomocysteinemia�cyanocobalamin was demonstrated to be equipotent in reducing plasma homocysteine levels in a comparison to hydroxycobalamin. In a 2001 study printed in JAMA, Tice et al. reported oral cyanocobalamin to be a cost-effective method of reducing plasma homocysteine levels in multiple population groups.
�B12 deficiency has been associated with alterations in cognition in the elderly. There is a known connection between elevations in homocysteine and age-related cognitive decline. The relationship must certainly include deficiencies of both folic acid and B12. Oral cyanocobalamin is capable of reducing serum methylmalonic acid concentrations�an indication of B12 repletion. Therefore, increasing the intake of B12 as cyanocobalamin may provide protection against cognitive decline in older populations.
�No toxic effects of oral B12 consumption have ever been reported at any level of intake. In a 1991 JAMA report, Hatchcock and Troendle reported no concerns with the oral use of B12. Cyanide release from oral B12 was said to be toxicologically insignificant. The lack of reported B12 toxicity is a testament to the effective and safe use of this oral compound.
Please see an independent article written by Metagenics that markets to health professionals with literature references comparing Cyanocobalamin with Methylcobalamin. I listed some bullets below from this article and other literature that discuss the important functions of Adenosylcobalamin (also called cobamamide/dibencozide) that the body synthesizes from cyanocobalamin or hydroxycobalamin. The body cannot make adenosylcobalamin from methylcobalamin.
Arrowind09,
Some added information regarding the different cobalamins. Would you give me your input based on the above information?
Thank you for your time and help.
|