<P> Essential fatty acids (EFAs) are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them . Only two fatty acids are known to be essential for humans: alpha - linolenic acid (an omega - 3 fatty acid) and linoleic acid (an omega - 6 fatty acid). </P> <P> Vitamins are organic molecules essential for an organism that are not classified as amino acids or fatty acids . They commonly function as enzymatic cofactors, metabolic regulators or antioxidants . Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules (e.g. vitamin E includes tocopherols and tocotrienols). The list: vitamins A, C, D, E, K, Thiamine (B), Riboflavin (B), Niacin (B), Pantothenic Acid (B), Vitamin B, Biotin (B), Folate (B) and Vitamin B . The requirement for vitamin D is conditional, as people who get sufficient exposure to ultraviolet light, either from the sun or an artificial source, synthesize vitamin D in skin . </P> <P> Minerals are the exogenous chemical elements indispensable for life . Although the four elements: carbon, hydrogen, oxygen, and nitrogen, are essential for life, they are so plentiful in food and drink that these are not considered nutrients and there are no recommended intakes for these as minerals . The need for nitrogen is addressed by requirements set for protein, which is composed of nitrogen - containing amino acids . Sulfur is essential, but again does not have a recommended intake . Instead, recommended intakes are identified for the sulfur - containing amino acids methionine and cysteine . There are dietary supplements which provide sulfur, such as methylsulfonylmethane . </P> <P> The essential nutrient elements for humans, listed in order of Recommended Dietary Allowance (expressed as a mass), are potassium, chlorine, sodium, calcium, phosphorus, magnesium, iron, zinc, manganese, copper, iodine, chromium, molybdenum, selenium and cobalt (the last as a component of vitamin B). There are other minerals which are essential for some plants and animals, but may or may not be essential for humans, such as boron and silicon . </P>

What are the 9 essential nutrients for the body