Zinc was also reportedly used to promote the healing of wounds by the Romans.
Here, the solubility of the drug can be an issue, along with competitive complexation with proteins in the bloodstream.
In some examples this complexation might be desirable to aid distribution of the drug to where it is required, in others it can be detrimental.
Table 9.1 lists the recommended daily intakes for some of the essential metals, together with some of the effects of deficiencies in these metals (reproduced from Table 1.1).
Table 9.1 UK Food Standards Agency reference nutrient intake (RNI) for adults (and the US Department of Agriculture dietary reference intakes (DRI)) and the effect of deficiency for selected essential metals.
Intensive research in this area has since spawned the development of other metal complexes for cancer therapy.