Expansion
Each is a cofactor whose loss produces a recognisable syndrome
Expansion
Zinc
- Cofactor for over 300 enzymes, including carbonic anhydrase, alkaline phosphatase and matrix metalloproteinases; also zinc finger transcription factors
- Deficiency: perioral and perianal dermatitis, alopecia, diarrhoea, impaired wound healing, taste disturbance, night blindness, impaired immunity
- Acrodermatitis enteropathica is the inherited malabsorption form, presenting on weaning
- Acquired deficiency: malabsorption, alcohol dependence, parenteral nutrition, burns
Copper
- Cofactor for lysyl oxidase (collagen and elastin cross linking), cytochrome c oxidase, superoxide dismutase and caeruloplasmin, which is a ferroxidase needed for iron mobilisation
- Deficiency: microcytic anaemia unresponsive to iron, neutropenia, osteoporosis, and a myelopathy resembling subacute combined degeneration. A recognised complication of excess zinc supplementation and of bariatric surgery
- Menkes disease is deficient absorption, with kinky hair and neurodegeneration; Wilson’s disease is the opposite, copper accumulation
Selenium
- Cofactor for glutathione peroxidase, an antioxidant, and for the deiodinases converting T4 to T3
- Deficiency: Keshan disease, a dilated cardiomyopathy, and Kashin-Beck osteoarthropathy
“Zinc for skin and healing, copper for collagen and iron, selenium for antioxidant defence and thyroid.”