UPSC 2016 CDS I GK Paper

Vitamin B12 deficiency causes pernicious anaemia. Animals cannot synthesise vitamin B12. Humans must obtain all their vitamin B12 from their diet. The complexing metal ion in vitamin B12 is Co3+ (Cobalt ion). The vitamin B12 group of molecules are the only cobalt-containing molecules (called 'cobalamins') associated with biochemistry of humans. It is the cobalt (III) ion complex that gives this water-soluble vitamin its distinctive red colour.