Excessive zinc intake will eventually affect the balance and propaer ratios with numerous other nutrients, which includes iron, calcium, selenium, nickel, phosphorus, copper, as well as Vitamin A, B1, C, and others. It may also cause, or contribute to gastrointestinal problems, vomiting, anemia, loss of libido, impotence, prostatitis, ovarian cysts, menstrual problems, renal tubular necrosis interstitial nephritis, dizziness, hair loss, depressed immune functions, muscle spasms, and sciatica, among others... Full Text