Gastrointestinal tract cobalt

As the name suggests, cyanocobalamin (vitamin B12) is a compound of cobalt (Co(lll)). With a complex organic structure, this essential water-soluble vitamin is obtained from dietary animal sources and is required for deoxyribonucleic acid (DNA) synthesis, where enzymes that use vitamin B12 are involved in the transfer of one-carbon units. The absorption of this vitamin from the gastrointestinal tract only occurs when intrinsic factor glycoprotein is present. While the body can store up to a 12-month supply of vitamin B12, rapid growth or conditions causing rapid cell turnover can increase the body s requirement for this vitamin. 

The bio-availabilities of these elements through the gastrointestinal tract vary markedly. Molybdenum, iodine, fluorine, and arsenic are apparently highly bio-available, whereas medium uptake occurs with haem iron, cobalt, zinc, chromium in the presence of a glucose tolerance factor, selenium, either as selenate or as organo selenium compounds, whereas only low bio-availability is experienced with non-haem iron,... 

Fig. 8. Differences in weight of thymus, spleen, and gastrointestinal tract of mice 2 days after exposure to graded doses of cobalt gamma rays for glutathione-treated and control mice.

In the gastrointestinal tract of humans, 20-97% of cobalt present in the diet is resorbed. For the resorption ofvitamin Bj2, a glycoprotein known as the gastric factor is essential, which allows the transport of cobalamin into cells in the intestinal mucosa. The effectiveness of cobalt resorption increases with iron deficiency. Cobalt is excreted from the body mainly in the urine. 

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