An element that is considered a non-essential nutrient is which of the following?

Essential elements are 14 in number, they are : calcium, chromium, copper, fluorine, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, and zinc. Lead is not an essential element. Essential macrominerals are those needed in significant quantities (such as calcium) - usually measured in milligrams, and essential trace minerals are those needed in minute quantities (such as selenium) - usually measured in micrograms. Sodium regulates plasma volume, acid-base balance, nerve and muscle function. Iron is an essential constituent of haemoglobin and ceain enzymes such as cytochrome oxidase, catalase, and peroxidase. Manganese is an essential trace mineral. Others are, cobalt, fluorine, iodine, chromium, selenium and molybdenum. They help in replacing electrolytes lost through heavy perspiration or extended diarrhoea and protects against toxic reaction and heavy metal poisoning. Ref: Clinical Biochemistry By Nanda Maheshwari, 2008, Page 76; Essential of Paediatrics By O.P.Ghai, 7th edition, Page 78