Cyanocobalamin liver tissue

Vitamin 5,2 (cyanocobalamin. Figure 14-9) is involved in the manufacture of the red corpuscles of the blood. It is used for the treatment of pernicious anemia, and it is perhaps the most potent substance known in its physiological activity 2 micrograms per day (2 x 10 g) of vitamin Bj2 is effective in the control of the disease. The vitamin can be isolated from liver tissue, and is also produced by molds and other microorganisms. Each molecule of vitamin B,2 contains one cobalt atom. This is the only compound of cobalt that is known to be present in the human body. 

Vitamin B12 (cyanocobalamin) is produced by bacteria B12 generated in the colon, however, is unavailable for absorption (see below). liver, meat, fish, and milk products are rich sources of the vitamin. The minimal requirement is about 1 pg/d. Enteral absorption of vitamin B 2 requires so-called intrinsic factor from parietal cells of the stomach. The complex formed with this glycoprotein undergoes endocytosis in the ileum. Bound to its transport protein, transcobalamin, vitamin B12 is destined for storage in the liver or uptake into tissues. 

Methylcobalamin is the coenzyme form of vitamin It is neurologically active, most bioavailable and best utilized. Unlike cyanocobalamin, it does not require any conversion after absorption by the body and is better retained by the liver and other tissues. It has exhibited beneficial effects against brain aging, irregular sleep patterns. It supports immune function and promote normal cell growth. It represents one of the best values in nutritional products, given its comparably low cost and its wide range of potential benefits. 

---