Zink och dess påverkan av testosteronproduktionen

[Whynot]

Kan vara obekvämt för det:

Although zinc is an essential requirement for good health, excess zinc can be harmful. Excessive absorption of zinc suppresses copper and iron absorption.[168] The free zinc ion in solution is highly toxic to plants, invertebrates, and even vertebrate fish.[188] The Free Ion Activity Model is well-established in the literature, and shows that just micromolar amounts of the free ion kills some organisms. A recent example showed 6 micromolar killing 93% of all Daphnia in water.[189]

The free zinc ion is a powerful Lewis acid up to the point of being corrosive. Stomach acid contains hydrochloric acid, in which metallic zinc dissolves readily to give corrosive zinc chloride. Swallowing a post-1982 American one cent piece (97.5% zinc) can cause damage to the stomach lining due to the high solubility of the zinc ion in the acidic stomach.[190]

There is evidence of induced copper deficiency at low intakes of 100–300 mg Zn/day; a recent trial had higher hospitalizations for urinary complications compared to placebo among elderly men taking 80 mg/day.[191] The USDA RDA is 11 and 8 mg Zn/day for men and women, respectively.[169] Even lower levels, closer to the RDA, may interfere with the utilization of copper and iron or adversely affect cholesterol.[168] Levels of zinc in excess of 500 ppm in soil interfere with the ability of plants to absorb other essential metals, such as iron and manganese.[84] There is also a condition called the zinc shakes or "zinc chills" that can be induced by the inhalation of freshly formed zinc oxide formed during the welding of galvanized materials.[114] Zinc is a common ingredient of denture cream which may contain between 17 and 38 mg of zinc per gram. There have been cases of disability or even death due to excessive use of these products.[192]

The U.S. Food and Drug Administration (FDA) has stated that zinc damages nerve receptors in the nose, which can cause anosmia. Reports of anosmia were also observed in the 1930s when zinc preparations were used in a failed attempt to prevent polio infections.[193] On June 16, 2009, the FDA said that consumers should stop using zinc-based intranasal cold products and ordered their removal from store shelves. The FDA said the loss of smell can be life-threatening because people with impaired smell cannot detect leaking gas or smoke and cannot tell if food has spoiled before they eat it.[194] Recent research suggests that the topical antimicrobial zinc pyrithione is a potent heat shock response inducer that may impair genomic integrity with induction of PARP-dependent energy crisis in cultured human keratinocytes and melanocytes.[195]
Poisoning