A<unk>  is an organic molecule (or a set of molecules closely related chemically, i.e.<unk> amers) that is an essential micronutrient which an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrients cannot be synthesized in the organism, either at all or not in sufficient quantities, and therefore must be obtained through the diet.<unk>  C can be synthesized by some species but not by others; it is not a<unk>  in the first instance but is in the second. The term<unk>  does not include the three other groups of essential nutrients: minerals, essential fatty acids, and essential amino acids. Most<unk> s are not single molecules, but groups of related molecules called<unk> amers. For example, there are eight<unk> amers of<unk>  E: four tocopherols and four tocotrienols. Some sources list fourteen<unk> s, by including choline, but major health organizations list thirteen:<unk>  A (as all-trans-retinol, all-trans-retinyl-esters, as well as all-trans-beta-carotene and other provitamin A carotenoids),<unk>  B1 (thiamine),<unk>  B2 (riboflavin),<unk>  B3 (niacin),<unk>  B5 (pantothenic acid),<unk>  B6 (pyridoxine),<unk>  B7 (biotin),<unk>  B9 (folic acid or folate),<unk>  B12 (cobalamins),<unk>  C (ascorbic acid),<unk>  D (calciferols),<unk>  E (tocopherols and tocotrienols), and<unk>  K (phylloquinone and menaquinones).<unk> s have diverse biochemical functions.<unk>  A acts as a regulator of cell and tissue growth and differentiation.<unk>  D provides a hormone-like function, regulating mineral metabolism for bones and other organs. The B complex<unk> s function as enzyme cofactors (coenzymes) or the precursors for them.<unk> s C and E function as antioxidants. Both deficient and excess intake of a<unk>  can potentially cause clinically significant illness, although excess intake of water-soluble<unk> s is less likely to do so. All<unk> s were discovered (identified) between 1913 and 1948. Historically, when intake of<unk> s from diet was lacking, the results were<unk>  deficiency diseases. Then, starting in 1935, commercially produced tablets of yeast-extract<unk>  B complex and semi-synthetic<unk>  C became available. This was followed in the 1950s by the mass production and marketing of<unk>  supplements, including multivitamins, to prevent<unk>  deficiencies in the general population. Governments have mandated the addition of some<unk> s to staple foods such as flour or milk, referred to as food fortification, to prevent deficiencies. Recommendations for folic acid supplementation during pregnancy reduced risk of infant neural tube defects.
Vitamin
Mineral 
Micronutrient
Nutrient
Protein 
Covid-Organics
Electrolyte
Hematogen