SO DYK
THYROID FUNCTION

Cobalt

Co — Element #27

also known as Cobalt chloride, Cobalt sulfate, Vitamin B12 (cobalamin)

Cobalt is an essential ultratrace mineral whose only confirmed biological role in humans is as the central atom of cobalamin (vitamin B12). It cannot be synthesized by the body and must be obtained pre-formed as B12 from animal-source foods or supplements; inorganic cobalt salts cannot substitute for B12. As an isolated inorganic mineral, cobalt has no established dietary requirement separate from B12.

  • As the core atom of vitamin B12 (cobalamin), cobalt is required for methionine synthase and methylmalonyl-CoA mutase reactions
  • B12-bound cobalt is essential for DNA synthesis, neurological function, and red blood cell maturation
  • Required for the conversion of homocysteine to methionine, reducing cardiovascular risk associated with hyperhomocysteinemia
  • Supports normal myelin sheath maintenance through B12-dependent enzyme activity

Active in Co²⁺ (cobaltous), Co³⁺ in cobalamin (vitamin B12).

No established UL for inorganic cobalt; toxicity from dietary sources is extremely unlikely
Cobalt toxicity (cobaltism) has occurred from occupational inhalation of cobalt dust (lung fibrosis, cardiomyopathy) and from cobalt-chromium metal-on-metal hip implant corrosion
High-dose inorganic cobalt supplements are not a valid substitute for vitamin B12 and are potentially harmful
Polycythemia (overproduction of red blood cells) has been induced experimentally by cobalt administration