One of the most intriguing aspects of micronutrients is its impact on nutrition partitioning and body composition.  The research on B vitamins is quite extensive and in particular the results of B12 (Glutathione) suggest a congruent relationship between blood glucose control and B12 metabolism.  The mechanisms between B12 and carbohydrate metabolism is still not fully understood, but the results of this study in 1954 were well ahead and suggested that the “administration of glutathione or vitamin B12 lowered the blood sugar levels of rats with hyperglycemia induced by a high carbohydrate-low fat diet and by glucose injections.”

Therefore we can deduct, that vitamin B12 plays an important role in carbohydrate and lipid metabolism.  In turn, B12 can increase a person’s nutritional partitioning and insulin response controlling the body’s composition by way less fat storage and more glycogen storage and muscle gain.

The research paper goes on to say,

“There are several plausible explanations of the mechanism of action by which glutathione could improve the utilization of carbohydrates, such as the activation of sulfhydryl enzymes and the protection of the Beta-cells in the pancreas from the deleterious effect of certain metabolic products, alloxan and dehydroascorbic acid for instance. Although these substances are usually found only in minute quantities in the animal body, their concentration can increase to a considerable extent under certain conditions. For example, Banerjee et al. found that dehydroascorbic acid was present in considerable amounts in scorbutic guinea pig tissues and that the glutathione content was markedly diminished in these tissues, and particularly so in the pancreas. However, the rapidity with which glutathione acts to lower the blood sugar after its injection suggests that this substance may be directly involved in the utilization of carbohydrate. This supposition is substantiated by the observations of Cavallini on the role of glutathione in the coupled oxidative decarboxylation of pyruvate and of Racker on the mechanism of glyoxalase function and by the discovery of Krimsky and Racker that glutathione is the prosthetic group of 3-phosphoglyceraldehyde dehydrogenase. “

Essentially, there is a better use of carbohydrates to produce energy in the form of ATP, in the presence of higher blood levels of B12 . To further the point, the research also shows how a vitamin B12 deficiency has the opposite effect therefore concluding that B12 plays a key role in carbohydrate and lipid use within the body.

As research has evolved we now know that all the B vitamins play a crucial role in carbohydrate metabolism.   In particular, for bodybuilders interested in lean muscle and transforming their body composition it is very important.  The best type of diet for building muscle is a high carbohydrate diet.  However, diets high in carbs require greater amounts of B Vitamins to maximize the response and enhance proper nutrition partitioning.   The best naturally found sources of B12 is in animal products, including fish, meat, poultry, eggs, milk, and milk products. Although Vitamin B12 is generally not present in plant foods, fortified breakfast cereals are a readily available source of vitamin B12 with high bioavailability for vegetarians.  You can also learn more about all the B-Vitamins and there function in the human body by visiting, https://en.wikipedia.org/wiki/B_vitamins

Chiun T. Ling and Bacon F. Chow METABOLISM CARBOHYDRATE AND LIPIDE THE INFLUENCE OF VITAMIN B12 ON J. Biol. Chem. Retrevied from: http://www.jbc.org/content/206/2/797.full.pdf