A vitamin is an organic molecule (or a group of molecules chemically linked, i.e. vitamers) that is an important micronutrient that an organism need in tiny amounts for appropriate metabolic function. Essential nutrients are unable to be produced in the body, either entirely or in adequate amounts, and must therefore be received via the food. Some species can synthesis vitamin C while others cannot; it is not a vitamin in the first case but is in the second. The three other classes of necessary nutrients, minerals, essential fatty acids, and essential amino acids, are not included in the name vitamin. Most vitamins are made up of vitamers, which are groupings of linked molecules. Vitamins serve a variety of biochemical purposes. Between 1913 and 1948, all vitamins were found. Vitamin deficiency disorders have historically resulted from a lack of vitamin intake from the food. Commercially made fermentation vitamin B complexes and semi-synthetic vitamin C pills became available in 1935. The widespread manufacture and marketing of vitamin supplements, particularly multivitamins, began in the 1950s to avoid vitamin deficiencies in the general population. To combat vitamin shortages, governments have forced the addition of some vitamins to staple foods such as bread or milk, a process known as food fortification. Folic acid supplementation during pregnancy was recommended to lower the risk of neural tube abnormalities in children. Water-soluble and fat-soluble vitamins are the two types of vitamins. There are 13 vitamins in humans, four of which are fat-soluble and nine of which are water-soluble. These are micronutrients that are essential for our health and the proper functioning of the human body. Although consumed in miniscule amount, they each play a crucial role in various processes in the body. Without consuming the optimum amount of vitamins, our bodies are prone to diseases such as scurvy, anemia, and even neurological disorders.