Vitamins are the organic substances present in natural food supplements. Vitamins are made up of organic molecules, which is an essential micronutrient that helps to function proper metabolism in the body. These essential nutrients cannot be synthesized by themselves. So, it is important for every organism to tabulate its diet chart including vitamins.
The vitamins are different from minerals, fatty acids, and amino acids. The vitamins have various biochemical functions. Vitamins are of six types namely vitamin A, vitamin B, vitamin C, vitamin D, vitamin E & vitamin K. Each vitamin has unique properties and molecular structure. This will take care of various biochemical functions in the body. Maximum vitamins are not made up of single molecules, but groups of molecules called vitamers.
Types of Vitamins
Vitamins are broadly classified into two types, based on their soluble pattern. They are listed below.
Water soluble vitamins
Fat soluble vitamins
The vitamin which is soluble in water is known as water soluble vitamins. The list of water soluble vitamins includes vitamin B and vitamin C.
The vitamins which are soluble in fats are termed fat soluble vitamins. The list of fat soluble vitamins includes vitamin A, vitamin D, vitamin E, and vitamin K.
Water Soluble Vitamins
The molecular substance present in the organic substance is called vitamins. The vitamin which is soluble in water is termed as water soluble vitamins. The degree of dissolving vitamins in water varies depending on substance properties. The degree of solubility varies depending on the property that influences the route of absorption, the excretion rate, and the level of tissue stage. The water soluble vitamins are extracted and stored in different methods. This molecule contains major elements like carbon, hydrogen, and oxygen. Some combination of vitamins also contains sulfur, nitrogen or cobalt.
The water soluble vitamins functions are mostly inactive in their free state, and it gets activated with their coenzyme forms. The addition of phosphate groups helps in the activation of thiamin, riboflavin, and vitamin B6. The modification in structure helps to activate biotin. Many complex molecules are involved in activating niacin, pantothenic acid, folic acid, and vitamin B12. Once the coenzyme activation occurred in vitamins, they started to combine with proper protein components, this process is termed as apoenzyme. This is the initial stage to undergo enzyme catalyzed reactions.
Water Soluble Vitamins Functions
The enzyme system requires transferring certain groups between molecules for the formation of vitamin B coenzymes. As a result of the formation of coenzymes specific proteins, fats and carbohydrates are synthesized and utilized for the production of body tissues or to store or release energy. For the formation of pantothenic acid coenzyme, vitamins need to undergo the tricarboxylic acid cycle. This process is also known as the Krebs cycle or citric acid cycle. This process gets interconnected with carbohydrate, protein, and fat metabolism. This coenzyme A acts as a hub for the reaction, as this molecule is controlling the interconversion of carbohydrates, fats, and proteins further, they are converted into metabolic energy. During the citric acid cycle, thiamin and vitamin B6 coenzymes limit the conversion of carbohydrates and proteins respectively. Niacin and riboflavin coenzymes help to transfer hydrogen ions or electrons, this mainly occurs during the tricarboxylic acid cycle. These coenzymes also facilitate transfer reactions. This reaction is not a part of the tricarboxylic acid cycle.
[Image will be Uploaded Soon]
The vitamin C enzyme-catalyzed reaction does not involve coenzyme formation. Its functional characteristics are related to the properties of a strong reducing agent.
Metabolism through Water Soluble Vitamins
The water-soluble vitamins get absorbed in the animal intestine and directly passed into the blood. The cells and tissues start utilizing it. Vitamin B12 requires a substance to get absorbed, it is known as an intrinsic factor. Some states of Vitamin B cannot be absorbed directly by animals. The animal intestine cannot absorb niacytin, which is the bounded form of niacin present in cereals grains. The raw egg white contains avidin, the bounded form of biotin. The digestive tract enzymes cannot absorb or break down such vitamins and remain unutilized. The biotin, vitamin B6, folic acid are bound with other molecules to form complexes or conjugated molecules in animal products. Although, none of the vitamins are in active form these three vitamins normally release the bounds by the action of enzymes in the intestinal tract or the tissues. Both plants and animal tissues distribute vitamin B for metabolism.
The water soluble vitamins get excreted through the urine. Elements like thiamin, vitamin B6, vitamin C, riboflavin, biotin, niacin, and pantothenic acid are excreted as free vitamins in urine. The products formed using the above vitamins can also be identified in urine. The excretion of vitamins through urine gets reduced once one starts intaking sufficient quantity. If the intake satisfies the minimal requirement, the excess vitamins will get stored in the tissues. As the tissue storage capacity is less, the excretion level starts to increase sharply once the tissues get saturated. Some water soluble vitamins name as vitamin B12, folic acid, and biotin get excreted through the faeces. The sources of water soluble vitamins for this discharge is intestinal bacteria.
The water soluble vitamins functions are generally toxic if it is taken in excessive amounts. But this has some exceptions in human beings. While an excess level of niacin helps for the dilation of blood vessels, an excessive amount of niacin impacts liver function. If the thiamin exceeds the requirement level by 100 times, it may result in respiratory failure. The recommended doses of thiamin do not cause such toxic effects in human beings. No other vitamin B causes such toxicity.