However, very high selenium dosages, above 900 mcg daily, are known to cause selenium toxicity. Signs of selenium toxicity include depression, nervousness, emotional instability, nausea, vomiting, and in some cases loss of hair and fingernails. Gallegos A, Berggren M, Gasdaska JR, and Powis G. Mechanisms of the regulation of thioredoxin reductase activity in cancer cells by the chemopreventive agent selenium. Harrison PR, Lanfear J, Wu L, Fleming J, McGarry L, and Blower L. Chemopreventive and growth inhibitory effects of selenium. Tolonen M. Finnish studies on antioxidants with special reference to cancer, cardiovascular diseases and aging.
Selenium compounds have disparate abilities to impose oxidative stress and induce apoptosis.
Effects of dietary selenium species on Se concentrations in hair, blood, and urine. 6.Wen HY, Davis RL, and Shi B. Bioavailability of selenium from veal, chicken, beef, lamb, flounder, tuna, selenomethionine, and sodium selenite assessed in selenium-deficient rats. Neve J. Human selenium supplementation as assessed by changes in blood selenium concentration and glutathione peroxidase activity. Peretz A, et al. Selenium in rheumatic diseases.