Selenium, Whole Blood

Selenium toxicity may occur due to industrial exposures or through drinking water in some parts of the world. Toxic symptoms include garlic breath odor, thick brittle fingernails, dry brittle hair, red swollen skin of the hands and feet, and nervous system abnormalities of numbness, convulsions, or paralysis.¹ Selenium is produced as a byproduct of copper refining and is used in electronic semiconductors, as a decolorizing agent for ceramics and glass, and as a vulcanizing agent in the rubber industry. The essential nature of selenium in human nutrition is now beyond dispute. Multiple cases of selenium deficiency have been reported in patients receiving parenteral nutrition for longer than one week when no selenium was included in their formula. Deficiency has also been reported in severe malnutrition without parenteral nutrition. The syndrome has included painful weak muscles and acute or chronic congestive heart failure due to cardiomyopathy that is sometimes fatal. Other findings noted in some cases of selenium deficiency include erythrocyte macrocytosis, depigmentation of skin and hair, and elevated transaminase and creatine kinase levels.