NFS382H1 Lecture Notes - Lecture 8: Vitamin B12 Deficiency, Megaloblastic Anemia, Enterohepatic Circulation
Document Summary
Corrin molecules made up of 4 reduced pyrrole rings with a cobalt molecule in the center. A nucleotide lying in a plane at nearly a right angle. A second bond exists between the cobalt atom to one of the nitrogen atoms of the nucleotide. Synthetic: cyanocobalamin and hydroxocobalamin are the synthetic forms of the vitamin very stable. Natural: coenzyme forms of the vitamin include 5-deoxyadenosylcobalamin and methylcobalamin unstable: sources. Only dietary sources for humans are from animal products which derive their cobalamins for micro-organisms. Best sources are meat and meat products, poultry, fish, shellfish, eggs. Can be found in milk and milk products. Bioavailability in meals range from 40-89: absorption. On average, a sedentary lifestyle results in lower caloric intake. People tend to have minimal animal product intake therefore, b12 deficiency is not just a problem for the elderly. B12 released from consumed tissue cells by acidic and mechanical action. Problem if low acid production (especially for the elderly)
