Essentiality and Toxicity of Trace Elements see Table

Iodine deficiency causes goiter in animals (and cretinism in humans) (Meng 1992, Anke et al. 2000). Iodine is a component of the important thyroid hormones, and 

Copper deficiency gives rise to many distinct aspects of pathology that can be identified with specific cuproenzymes - for example, depigmentation and low tyrosinase activity or aortic rupture and bone disorders and low lysyl oxidase activity. The normative copper requirement of non-ruminants is 

Sydenham, Menghini, 16th century, Bous-singault 1872 

Shen Ning, third millennium BC, Hippocrates 460-370BC, Coindet 1820, Boussin-gault, iodization of salt, Chatin 1851 

Iron salts restored skin color, iron in blood, Fe, a nutrient, hemoglobin, 0.35% Fe 

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