Like most soluble materials,<unk>  compounds are readily absorbed by the stomach and intestines, and excreted through the urine. Urine tests have been used to ascertain rates of excretion in order to set upper limits in exposure to<unk>  compounds and associated detrimental health effects. Ingested<unk>  initially acts locally on the intestinal mucosa, where it forms hydrofluoric acid in the stomach.
Fluoride toxicity
Fluorine deficiency
Chromium toxicity
Copper toxicity
Boron deficiency 
Lead poisoning
Zinc toxicity
Chromium deficiency