Bismuth
BISMUTH is a heavy metal found in many medications used for anything from ear infections to hemorrhoids to stomach disorders -- most notably being Pepto-Bismol. It is also used for cosmetics and ointments. Although absorption from food is low, there has been concern recently over the possible toxic effects of ingested bismuth from pharmaceutical products. Accumulation is low in most organs, with the highest amounts found in the kidneys and the lowest in the liver. Retention is directly linked to dietary zinc levels with metallothionein directly involved in the relationship. Both bismuth and zinc induce metallothionein formation and thus, the intake of one may increase retention of the other. (Metallothionein is a cysteine-rich protein that binds zinc, cadmium, and copper and is important for binding metal ions preventing toxicity).
Bismuth is not a common metal, and its natural distribution is limited. It is obtained mainly as a byproduct of lead and copper refining. Industrially, it is used in certain alloys and in nuclear reactors. There is no evidence that it plays an essential role in nutrition, but there is concern as to its effects regarding health. There is evidence that it causes renal damage and encephalopathy in high doses. Poisonings have occurred as a result of large oral intakes from pharmaceutical products. Bismuth can cause skin irritations and pigment change. It causes anorexia, headaches, rashes, neurological disorders, impaired kidney function, stomach ulcers as well as ulcers of the mouth and lips.
