An essential nutrient. Noncaloric organic nutrients needed in tiny amounts in the diet.
Organic substances of plant or animal origin that are essential for normal growth, development, metabolic processes, and energy transformations.
An organic compound required in tiny amounts (for the growth, proper biological functioning and maintenance of health of an organism). Vitamins are commonly classified into two categories, the fat soluble and the water soluble. Vitamins A, D, E, and K are fat soluble whereas vitamin C and members of the vitamin B complex group are water soluble. In general, the vitamins play catalytic and regulatory roles in the body’s metabolism. Among the water-soluble vitamins, the B vitamins apparently function as coenzymes (nonprotein parts of enzymes). Vitamin C’s coenzyme role, if any, has not been established. Part of the importance of vitamin C to the body may arise from its strong antioxidant action. The functions of the fat-soluble vitamins are less well understood. Some of them, too, may contribute to enzyme activity; and others are essential to the functioning of cellular membranes (on surface of cells). Vitamin A is able to regulate the expression of certain genes in the embryos of mammals, via one of its metabolites; retinoic acid. Those embryo cells contain nuclear receptors (which bring the retinoic acid “signal” from outside into the cell’s nucleus) on their cell membrane surface. The retinoic acid then (via the nuclear receptors) regulates the expression of the genes that cause embryonic cell differentiation into complex body structures, such as legs and arms, of the growing embryo.
Organic substances (meaning they contain carbon) that the body requires to help regulate metabolic functions. For the most part, vitamins must be ingested; the body cannot manufacture them. Exceptions are vitamin D, which the body can synthesize, and to some extent vitamin K, which the body can produce from the bacteria that normally inhabit the intestines.
A general term for substances that occur in many plant and animal foods and are necessary in extremely small amounts for normal body function.
Organic compounds essential in very small amounts for promoting growth and maintaining life. They are abundant in the foods available to people act as catalysts as they interact with each other and with other nutrients. They are categorized according to their solubility in water or fats (Table V-l).
An essential substance not synthesised in the body, but found in most foods, and needed for good health.
A group of small organic compounds that cannot be synthesized in the body and, therefore, are considered essential nutrients. They are divided into two groups: (1) fat-soluble vitamins, and (2) water-soluble vitamins. The fat-soluble vitamins include vitamins A, D, E, and K. The water- soluble vitamins include thiamin, riboflavin, niacin, pyridoxine, pantothenic acid, biotin, vitamin B12, choline, and ascorbic acid.
Essential food nutrients required in very small quantities for the proper functioning of the body; chemically they are of widely diverse types.
Vitamins are organic molecules that are required in the diet but only in minute amounts. Although some vitamins can be synthesized by the human body (such as niacin from tryptophan, vitamin D from cholesterol, vitamin A from carotenoids, and perhaps choline from serine and methionine) or by bacteria within the colon (such as vitamin K, biotin, etc.), the amount produced is usually inadequate to meet the full demands of the body. Although many vitamins as well as multivitamins have been marketed as ergogenic aids, well-designed studies have largely failed to support the need for supplementation of any vitamin in nondeficient athletes. For each vitamin, it is very likely that a clinical deficiency will impair athletic performance in some way.
A group of complex chemical compounds that are vital to the normal functioning of the body. They do not in themselves provide energy or build the body, but they are necessary for the transformation of food into energy to perform those functions. Inadequate amounts of vitamins in the body can have serious consequences, often leading to disorders called deficiency diseases. Vitamins are made up largely of the same elements—carbon, hydrogen, oxygen, and sometimes nitrogen—but they have different chemical arrangements and functions in the body. Before the chemical makeup of vitamins was known, they were called by letters; in some cases (such as vitamin B), it was later found that several different vitamins were involved, so numbers were added as well (as in vitamins B|2 and B6). On the other hand, some things originally thought to be vitamins turned out to be inessential and so were dropped from the list, and sometimes different letters were given to vitamins that were later found to be the same. The result is various gaps in lettering and numbering.
Any of a group of organic compounds mat, m very small amounts, are essential for normal growth, development, and metabolism. They cannot be synthesized in the body (with a few exceptions) and must be supplied by the diet. Lack of sufficient quantities of any of the vitamins produces a specific deficiency disease. Vitamins are generally classified as water- soluble or fat-soluble. The water-soluble vitamins are the vitamin-B complex and vitamin C; the fat-soluble vitamins are vitamins A, D, E, and K.
Complex chemical compounds that the body cannot manufacture but are essential for good health. Vitamins regulate chemical processes in the body and are essential to immune system maintenance. They have a role in both maintaining health and preventing disease. A deficiency of vitamins leads to a wide range of diseases, from birth defects (most often due to folic acid deficiency) to scurvy (caused by a lack of vitamin C).
Any of a group of substances that are required, in very small amounts, for healthy growth and development: they cannot be synthesized in the body and are therefore essential constituents of the diet. Vitamins are divided into two groups, according to whether they are soluble in water or fat. The water-soluble group includes the vitamin B complex and vitamin C; the fat-soluble vitamins are vitamins A, D, E, and K. Lack of sufficient quantities of any of the vitamins in the diet results in specific vitamin deficiency diseases.
Any complex, organic compound, found in various food or sometimes synthesized in the body, required in tiny amounts and are essential for the regulation of metabolism, normal growth and function of the body.
An organic substance found in foods which performs specific and vital functions in the cells and tissues of the body.
Chemical compounds that are essential for normal functioning of the body. Vitamins regulate chemical processes in the body and have a role in maintaining health and preventing disease. A deficiency of vitamins can lead to a wide range of diseases, from birth defects (caused by a folic acid deficiency) to scurvy (caused by a lack of vitamin C). Vitamins can be water-soluble or fat-soluble. Water- soluble vitamins mix easily in the blood. The body is able to store only small amounts of these vitamins, most of which are excreted in urine and sweat. For this reason, water- soluble vitamins must be replaced daily. The water-soluble vitamins are vitamin C and the B complex vitamins—including thiamin (Bi), riboflavin (B2), niacin (B3), pyridoxine (B6), cyanocobalamin (B12), folic acid, and biotin. The fat-soluble vitamins—A, D, E, and K—are found in fats and oils in foods and are stored in the body’s fat cells. If a person takes too many fat-soluble vitamins, the vitamins can build up in the body and have harmful effects.
A term applied to a group of substances which exist in minute quantities in natural foods, and which are necessary to normal nutrition, especially in connection with growth and development. Some — A, D, E and K — are fat-soluble and can be stored in the body. The remainder — C, B12 and other members of the B complex — are water-soluble and are quickly excreted. Most vitamins have now been synthesized. When they are absent from the food, defective growth takes place in young animals and children, and in adults various diseases arise; whilst falling short of the production of actual disease, persistent deprivation of one or other vitamin is apt to lead to a state of lowered general health. Certain deficiencies in diet have long been known to be the cause of scurvy, beriberi, and rickets. A diet containing foods such as milk, eggs, butter, cheese, fat, fish, whole-meal bread, fresh vegetables and fruit should contain sufficient vitamins. Details of the various vitamins are given in appendix 5: vitamins.
An accessory but vital nutrient that serves as a coenzyme or cofactor in an essential metabolic process. Small quantities of the substance assist biological reactions such as oxidation and reduction, or the synthesis of nucleic acids, hemoglobin, clotting factors, or collagen. Vitamin deficiencies produce well-recognized syndromes (e.g., scurvy [vitamin C deficiency], or beriberi [thiamine deficiency]). Unlike proteins, carbohydrates, fats, and organic salts, vitamins are not energy sources or components of body structures. Instead, they are agents that hasten or facilitate biochemical processes involving these other organic molecules.
One of a group of unrelated substances that are essential in trace amounts for healthy growth and development; they cannot be synthesized in the body but occur naturally in certain plant and animal foods.
Vitamins are organic catalysts necessary to initiate the body’s complex metabolic functions.
A class of nutrients that contain carbon and that are needed in small amounts to maintain health and allow growth.
Nutrient necessary for normal functioning of the body; two types are water soluble and fat soluble.
A key nutrient that the body needs in small amounts to grow and stay strong. Examples are vitamins A, C and E.
Organic compounds that help release energy from food and act as metabolic regulators. Vitamins A, D, E, and K are fat soluble. The rest are water soluble.
Essential organic substances the body needs in minute amounts to support growth, to maintain bodily tissues, and to metabolize food.
Essential organic compounds, in minute quantities, are a prerequisite in a diet for the regulation and promotion of various bodily functions vital for growth, reproduction, and maintenance of the body.
Vitamins are organic compounds that the human body is incapable of synthesizing on its own, yet they are indispensable for proper physiological functioning. Despite not being a source of energy, they act as catalysts that facilitate the production and utilization of energy within the body. In essence, vitamins are the driving force behind various biological processes that are necessary for maintaining optimal health. It is noteworthy that vitamins A, D, E, and K are lipid-soluble, while the B and C vitamins are hydrophilic.
Nutrients are a group of food substances that are essential for maintaining life and health, although they do not provide energy. They are found in varying quantities in most foods in their natural state and include vitamins, minerals, fiber, and water.
Chemical compounds, present in trace quantities, play a vital role in maintaining optimal health by effectively governing the body’s metabolic functions. These essential substances are naturally present in various food sources, ensuring that a well-balanced and diverse diet adequately provides the body with the necessary vitamins for its nourishment.
A micronutrient is a vital substance that the body requires in trace amounts to maintain optimal health. However, the body is incapable of producing these nutrients on its own and must obtain them through dietary sources.
Vitamins are a class of essential organic compounds needed in small quantities for the body to function properly. There are 13 known vitamins, including A, C, D, E, K, B12, and seven others that are part of the B complex. Except for vitamin D, which the body can produce on its own, all vitamins must be acquired through diet. A balanced diet usually provides sufficient amounts of each vitamin, but supplements may be beneficial for specific groups such as young children, pregnant or nursing women, or individuals on medication that disrupts vitamin absorption or function.
Vitamins are classified into two categories: fat-soluble and water-soluble.
Fat-soluble vitamins, which include A, D, E, and K, are absorbed through the intestines along with fats and then stored primarily in the liver’s fatty tissues. Because the body can store some of these vitamins for extended periods, daily consumption is not always required. A deficiency in fat-soluble vitamins typically arises from either a long-term inadequate diet or a medical condition that hampers the intestine’s ability to absorb fats.
Vitamins like C, B12, and others in the B complex are water-soluble. Unlike fat-soluble vitamins, these can only be stored in the body in small quantities and any excess is expelled through urine. Therefore, consistent intake is necessary to avoid a deficiency. However, an exception is vitamin B12, which can be stored in the liver for several years.
The full extent of how each vitamin functions in the body is not completely understood. Many vitamins have multiple significant effects on various bodily systems, and they often play a role in enzyme activities.
Vitamins are a collection of organic substances that, although only required in trace amounts in our diets, are crucial for our bodies’ normal growth and maintenance. Our bodies cannot produce these compounds on their own, necessitating their intake through our food. They don’t directly provide energy but are indispensable for energy conversion and metabolic regulation processes. Initially, it was believed that vitamins were a type of chemical known as amines, leading to the term ‘vital amines.’ This term was eventually abbreviated to ‘vitamins’.
Vitamins are a group of organic compounds found in small quantities in natural foods. They are crucial for normal growth and maintaining life because the body cannot produce them on its own. Vitamins are effective even in small doses. They don’t provide energy themselves but play a vital role in converting and regulating metabolism. Initially, when vitamins were first discovered, they were believed to be a type of chemicals called amines, and they were named “vital amines,” which was later shortened to “vitamins.”