A generic descriptor for all TOCOPHEROLS and TOCOTRIENOLS that exhibit ALPHA-TOCOPHEROL activity. By virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus, these compounds exhibit varying degree of antioxidant activity, depending on the site and number of methyl groups and the type of ISOPRENOIDS.
Vitamin E Deficiency
A nutritional condition produced by a deficiency of VITAMIN E in the diet, characterized by posterior column and spinocerebellar tract abnormalities, areflexia, ophthalmoplegia, and disturbances of gait, proprioception, and vibration. In premature infants vitamin E deficiency is associated with hemolytic anemia, thrombocytosis, edema, intraventricular hemorrhage, and increasing risk of retrolental fibroplasia and bronchopulmonary dysplasia. An apparent inborn error of vitamin E metabolism, named familial isolated vitamin E deficiency, has recently been identified. (Cecil Textbook of Medicine, 19th ed, p1181)
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.
Vitamin B 12
A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.
Vitamin A Deficiency
A nutritional condition produced by a deficiency of VITAMIN A in the diet, characterized by NIGHT BLINDNESS and other ocular manifestations such as dryness of the conjunctiva and later of the cornea (XEROPHTHALMIA). Vitamin A deficiency is a very common problem worldwide, particularly in developing countries as a consequence of famine or shortages of vitamin A-rich foods. In the United States it is found among the urban poor, the elderly, alcoholics, and patients with malabsorption. (From Cecil Textbook of Medicine, 19th ed, p1179)
Vitamin D Deficiency
A nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as RICKETS in children and OSTEOMALACIA in adults. (From Cecil Textbook of Medicine, 19th ed, p1406)
A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.
A natural tocopherol and one of the most potent antioxidant tocopherols. It exhibits antioxidant activity by virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus. It has four methyl groups on the 6-chromanol nucleus. The natural d form of alpha-tocopherol is more active than its synthetic dl-alpha-tocopherol racemic mixture.
A collective name for a group of closely related lipids that contain substitutions on the 2H-1-benzopyran-6-ol nucleus and a long hydrocarbon chain of isoprenoid units. They are antioxidants by virtue of the phenolic hydrogen. Tocopherols react with the most reactive form of oxygen and protect unsaturated fatty acids from oxidation.
Vitamin K 1
A family of phylloquinones that contains a ring of 2-methyl-1,4-naphthoquinone and an isoprenoid side chain. Members of this group of vitamin K 1 have only one double bond on the proximal isoprene unit. Rich sources of vitamin K 1 include green plants, algae, and photosynthetic bacteria. Vitamin K1 has antihemorrhagic and prothrombogenic activity.
Products in capsule, tablet or liquid form that provide dietary ingredients, and that are intended to be taken by mouth to increase the intake of nutrients. Dietary supplements can include macronutrients, such as proteins, carbohydrates, and fats; and/or MICRONUTRIENTS, such as VITAMINS; MINERALS; and PHYTOCHEMICALS.
Vitamin B 6
VITAMIN B 6 refers to several PICOLINES (especially PYRIDOXINE; PYRIDOXAL; & PYRIDOXAMINE) that are efficiently converted by the body to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, and aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into PYRIDOXAMINE phosphate. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990). Most of vitamin B6 is eventually degraded to PYRIDOXIC ACID and excreted in the urine.
Vitamin B 12 Deficiency
A nutritional condition produced by a deficiency of VITAMIN B 12 in the diet, characterized by megaloblastic anemia. Since vitamin B 12 is not present in plants, humans have obtained their supply from animal products, from multivitamin supplements in the form of pills, and as additives to food preparations. A wide variety of neuropsychiatric abnormalities is also seen in vitamin B 12 deficiency and appears to be due to an undefined defect involving myelin synthesis. (From Cecil Textbook of Medicine, 19th ed, p848)
Vitamin K Deficiency
A nutritional condition produced by a deficiency of VITAMIN K in the diet, characterized by an increased tendency to hemorrhage (HEMORRHAGIC DISORDERS). Such bleeding episodes may be particularly severe in newborn infants. (From Cecil Textbook of Medicine, 19th ed, p1182)
Vitamin B 6 Deficiency
A nutritional condition produced by a deficiency of VITAMIN B 6 in the diet, characterized by dermatitis, glossitis, cheilosis, and stomatitis. Marked deficiency causes irritability, weakness, depression, dizziness, peripheral neuropathy, and seizures. In infants and children typical manifestations are diarrhea, anemia, and seizures. Deficiency can be caused by certain medications, such as isoniazid.
Natural analogs of TOCOPHEROLS exhibiting antioxidant activity. These tocol derivatives and isomers contain a benzopyran ring and an unsaturated isoprenoid side chain.
A carotenoid that is a precursor of VITAMIN A. It is administered to reduce the severity of photosensitivity reactions in patients with erythropoietic protoporphyria (PORPHYRIA, ERYTHROPOIETIC). (From Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Engewood, CO, 1995.)
A natural tocopherol with less antioxidant activity than ALPHA-TOCOPHEROL. It exhibits antioxidant activity by virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus. As in BETA-TOCOPHEROL, it also has three methyl groups on the 6-chromanol nucleus but at different sites.
Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.
Proteins, usually found in the cytoplasm, that specifically bind calcitriol, migrate to the nucleus, and regulate transcription of specific segments of DNA with the participation of D receptor interacting proteins (called DRIP). Vitamin D is converted in the liver and kidney to calcitriol and ultimately acts through these receptors.
Vitamin D-Binding Protein
An alpha-globulin found in the plasma of man and other vertebrates. It is apparently synthesized in the liver and carries vitamin D and its metabolites through the circulation and mediates the response of tissue. It is also known as group-specific component (Gc). Gc subtypes are used to determine specific phenotypes and gene frequencies. These data are employed in the classification of population groups, paternity investigations, and in forensic medicine.
The 4-methanol form of VITAMIN B 6 which is converted to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990).
Vitamin K 2
A condition due to a deficiency of one or more essential vitamins. (Dorland, 27th ed)
The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.
Peroxides produced in the presence of a free radical by the oxidation of unsaturated fatty acids in the cell in the presence of molecular oxygen. The formation of lipid peroxides results in the destruction of the original lipid leading to the loss of integrity of the membranes. They therefore cause a variety of toxic effects in vivo and their formation is considered a pathological process in biological systems. Their formation can be inhibited by antioxidants, such as vitamin E, structural separation or low oxygen tension.
Any food that has been supplemented with essential nutrients either in quantities that are greater than those present normally, or which are not present in the food normally. Fortified food includes also food to which various nutrients have been added to compensate for those removed by refinement or processing. (From Segen, Dictionary of Modern Medicine, 1992)
Thiobarbituric Acid Reactive Substances
Vitamin B Deficiency
Derivatives of ERGOSTEROL formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. They differ from CHOLECALCIFEROL in having a double bond between C22 and C23 and a methyl group at C24.
Vitamin K 3
Vitamin K Deficiency Bleeding
Hemorrhage caused by vitamin K deficiency.
Disorders caused by interruption of BONE MINERALIZATION manifesting as OSTEOMALACIA in adults and characteristic deformities in infancy and childhood due to disturbances in normal BONE FORMATION. The mineralization process may be interrupted by disruption of VITAMIN D; PHOSPHORUS; or CALCIUM homeostasis, resulting from dietary deficiencies, or acquired, or inherited metabolic, or hormonal disturbances.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Dose-Response Relationship, Drug
Sodium-Coupled Vitamin C Transporters
Membrane transport proteins that actively co-transport ASCORBIC ACID and sodium ions across the CELL MEMBRANE. Dietary absorption of VITAMIN C is highly dependent upon this class of transporters and a subset of SODIUM GLUCOSE TRANSPORTERS which transport the oxidized form of vitamin C, DEHYDROASCORBIC ACID.
25-Hydroxyvitamin D3 1-alpha-Hydroxylase
A mitochondrial cytochrome P450 enzyme that catalyzes the 1-alpha-hydroxylation of 25-hydroxyvitamin D3 (also known as 25-hydroxycholecalciferol) in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP27B1 gene, converts 25-hydroxyvitamin D3 to 1-alpha,25-dihydroxyvitamin D3 which is the active form of VITAMIN D in regulating bone growth and calcium metabolism. This enzyme is also active on plant 25-hydroxyvitamin D2 (ergocalciferol).
Native, inorganic or fossilized organic substances having a definite chemical composition and formed by inorganic reactions. They may occur as individual crystals or may be disseminated in some other mineral or rock. (Grant & Hackh's Chemical Dictionary, 5th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Vitamin K Epoxide Reductases
OXIDOREDUCTASES which mediate vitamin K metabolism by converting inactive vitamin K 2,3-epoxide to active vitamin K.
Nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as FLAVIN MONONUCLEOTIDE and FLAVIN-ADENINE DINUCLEOTIDE.
Isoprostanes derived from the free radical oxidation of ARACHIDONIC ACID. Although similar in structure to enzymatically synthesized prostaglandin F2alpha (DINOPROST), they occur through non-enzymatic oxidation of cell membrane lipids.
A group of carrier proteins which bind with VITAMIN B12 in the BLOOD and aid in its transport. Transcobalamin I migrates electrophoretically as a beta-globulin, while transcobalamins II and III migrate as alpha-globulins.
Chromatography, High Pressure Liquid
25-Hydroxyvitamin D 2
9,10-Secoergosta-5,7,10(19),22-tetraene-3,25-diol. Biologically active metabolite of vitamin D2 which is more active in curing rickets than its parent. The compound is believed to attach to the same receptor as vitamin D2 and 25-hydroxyvitamin D3.
A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.
A malonic acid derivative which is a vital intermediate in the metabolism of fat and protein. Abnormalities in methylmalonic acid metabolism lead to methylmalonic aciduria. This metabolic disease is attributed to a block in the enzymatic conversion of methylmalonyl CoA to succinyl CoA.
A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)
A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.
Vitamin D Response Element
The edible portions of any animal used for food including domestic mammals (the major ones being cattle, swine, and sheep) along with poultry, fish, shellfish, and game.
Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.
This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).
Dryness of the eye surfaces caused by deficiency of tears or conjunctival secretions. It may be associated with vitamin A deficiency, trauma, or any condition in which the eyelids do not close completely.
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
A symptom complex resulting from ingesting excessive amounts of VITAMIN A.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Any dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
An autosomal recessive disorder of lipid metabolism. It is caused by mutation of the microsomal triglyceride transfer protein that catalyzes the transport of lipids (TRIGLYCERIDES; CHOLESTEROL ESTERS; PHOSPHOLIPIDS) and is required in the secretion of BETA-LIPOPROTEINS (low density lipoproteins or LDL). Features include defective intestinal lipid absorption, very low serum cholesterol level, and near absent LDL.
24,25-Dihydroxyvitamin D 3
Guidelines and objectives pertaining to food supply and nutrition including recommendations for healthy diet.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
A class of lipoproteins of small size (18-25 nm) and light (1.019-1.063 g/ml) particles with a core composed mainly of CHOLESTEROL ESTERS and smaller amounts of TRIGLYCERIDES. The surface monolayer consists mostly of PHOSPHOLIPIDS, a single copy of APOLIPOPROTEIN B-100, and free cholesterol molecules. The main LDL function is to transport cholesterol and cholesterol esters to extrahepatic tissues.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
General term for a group of MALNUTRITION syndromes caused by failure of normal INTESTINAL ABSORPTION of nutrients.
The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.
Fatty Acids, Unsaturated
Folic Acid Deficiency
A nutritional condition produced by a deficiency of FOLIC ACID in the diet. Many plant and animal tissues contain folic acid, abundant in green leafy vegetables, yeast, liver, and mushrooms but destroyed by long-term cooking. Alcohol interferes with its intermediate metabolism and absorption. Folic acid deficiency may develop in long-term anticonvulsant therapy or with use of oral contraceptives. This deficiency causes anemia, macrocytic anemia, and megaloblastic anemia. It is indistinguishable from vitamin B 12 deficiency in peripheral blood and bone marrow findings, but the neurologic lesions seen in B 12 deficiency do not occur. (Merck Manual, 16th ed)
Proteins which bind with RETINOL. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of about 21 kDa. The retinol-protein complex (MW=80-90 kDa) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14 kDa and carries retinol as a non-covalently-bound ligand.