Natural Bioactive B12 


Adenosylcobalamin is a popular B12 in the USA. It is one of the two bioactive coenzyme forms of vitamin B12 which occur naturally in foods.

Adenosylcobalamin – Natural and Bioactive Vitamin B12

Adenosylcobalamin is a naturally occurring form of vitamin B12, and, alongside hydroxocobalamin, the most common form of vitamin B12 found in foods.Additionally, Adenosylcobalamin, like methylcobalamin, is one of the two bioactive coenzyme forms of vitamin B12; the forms which our bodies really need. All other forms of vitamin B12 must first be converted into methylcobalamin or adenosylcobalamin inside the body, in order to be utilized. 

For most people, this conversion is risk-free, however, in some cases it can become impaired through genetic disorders, nutrient deficiencies or metabolic disorders. 

The Effect of Adenosylcobalamin 

Adenosylcobalamin is the most common form of vitamin B12 in our body cells, and above all in the liver – our largest vitamin B12 store. However, adenosylcobalamin is used predominantly in the mitochondria, which function as the ‘engine room’ of our cells.  

Energy Production

Adenosylcobalamin acts within the mitochondria as a chemical building block of the enzyme methylmalonyl-CoA mutase,  which is responsible for the conversion of methylmalonyl-CoA to succinyl-CoA, which is part of the citric acid cycle, a central metabolic cycle for the production of energy.2,3

Detoxification, Nerves and Tiredness

This reaction reduces the dangerous methylmalonic acid, which, amongst other things, has a severe nerve-damaging effect. If adenosylcobalamin is lacking, then methylmalonic acid levels rise and the body’s ability to produce energy falls. This can lead to numerous symptoms, which range from minor to life-threatening: chronic tiredness and exhaustion, muscle weakness, loss of weight, development difficulties and nerve damage are just some of the possible consequences. 

Hormones and Amino Acids

In addition to this important effect, adenosylcobalamin is also involved in the provision of important amino acids and hormones, for example valine, isoleucine, threonine, methionine, thymine and cholesterol. 

Application of Adenosylcobalamin

Medically speaking, adenosylcobalamin has been used very successfully for many years by numerous doctors and naturopaths, in the form of adenosylcobalamin vials, drops and capsules, all of which are available in pharmacies. According to its spectrum of effects, adenosylcobalamin is useful in combating the following:

  • Chronic tiredness and exhaustion
  • Muscle weakness
  • Weight loss and anorexia4
  • Fibromyalgia
  • Liver damage
  • Hepatitis5

Adenosylcobalamin – Important in the Treatment of Many Diseases

According to the experiences of numerous therapists, administering adenosylcobalamin represents an interesting therapeutic option against the diseases listed above and many other serious illnesses. Sufferers of the symptoms listed above should seek advice from a micronutrient specialist regarding the possible uses of adenosylcobalamin. 

Additionally, in cases where other B12 forms don’t produce a satisfactory effect, an extension of the planned therapy with the introduction of adenosylcobalamin is often suggested. 


1 Farquharson J, Adams JF. The forms of vitamin B12 in foods. Br J Nutr. 1976 Jul;36(1):127-36. PubMed PMID: 820366.
2 Marsh EN. Coenzyme B12 (cobalamin)-dependent enzymes. Essays Biochem. 1999;34:139-54. Review. PubMed PMID: 10730193.
3 Wood, H. G., Kellermeyer, R. W., Stjernholm, R. and Allen, S. H. G. (1964), METABOLISM OF METHYLMALONYL-CoA AND THE ROLE OF BIOTIN AND B12 COENZYMES. Annals of the New York Academy of Sciences, 112: 661–679. doi: 10.1111/j.1749-6632.1964.tb45043.x
4 Korkina MB, Korchak GM, Medvedev DI Clinico-experimental substantiation of the use of carnitine and cobalamin in the treatment of anorexia nervosa Zhurnal Nevropatologii i Psikhiatrii Imeni S.S. Korsakova (Moscow, Russia : 1952) [1989, 89(2):82-87] (PMID:2728726)
5 Iwarson S, Lindberg J Coenzyme-B12 therapy in acute viral hepatitis. Scandinavian Journal of Infectious Diseases [1977, 9(2):157-158](PMID:897571)

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