Vitamins are essential for our bodies to develop and function normally. They are organic substances that are divided into two categories: fat-soluble and water-soluble.
Fat-soluble vitamins(vitamin A, vitamin D, vitamin E, and vitamin K) dissolve in fat and accumulate in the body, while water-soluble vitamins (vitamin C and B-complex vitamins, such as vitamin B6, vitamin B12, and folate) must dissolve in water before they can be absorbed. If a vitamin is absent in the diet or is not properly absorbed by the body, a deficiency disease can develop.
Europe has regulations that define dose limits for vitamins (and minerals) for safe use as dietary supplements. The group of vitamins goes directly from E to K because the vitamins corresponding to the letters F—J were reclassified over time, dismissed as false clues, or renamed because of their relationship with vitamin B, which became a vitamin complex.
Water-soluble vitaminsinclude thiamine, riboflavin, niacin, vitamin B6, folic acid, vitamin B12, pantothenic acid, biotin, and vitamin C. The value of eating certain foods to maintain health was recognized long before vitamins were identified.
In 1943, Edward Adelbert Doisy and Henrik Dam received the Nobel Prize in Physiology or Medicine for their discovery of vitamin K and its chemical structure. It is assumed that most vitamins sold as dietary supplements should not exceed the maximum daily dose called the maximum tolerable intake level (UL or upper limit). The recommended dietary allowances (RDA) for vitamins reflect the amount of each vitamin that most people should consume each day. Soon after, researchers determined the specific amounts of vitamins needed to prevent deficiency diseases.
In 1910, the Japanese scientist Umetaro Suzuki isolated the first vitamin complex from rice bran and called it aberic acid (later Orizanin). Vitamin B3 (niacin and niacinamide) is not stored in significant quantities so reserves can last only a couple of weeks. All vitamins can be synthesized or produced commercially from food sources and are available for human consumption in pharmaceutical preparations. Then, starting in 1935, commercially produced vitamin B complex tablets with yeast extract and semisynthetic vitamin C became available.
It is important to note that an obsessive consumption of vitamins and multivitamins may not have beneficial effects.