74 Pantothenic Acid Synonyms Vitamin B5, antidermatosis vitamin, chick antidermatitis factor, chick antipellagra factor Chemistry Pantothenic acid is composed of beta-alanine and 2,4-dihydroxy-3,3- dimethyIbutyric acid (pantoic acid), acid amide-linked. Pantetheine consists of pantothenic acid linked to a ß-mercaptoethylamine group. Calcium pantothenate crystals in polarised light CH3 OH HO CH2 C C C N CH2 CH2 COOH H CH3 H O Molecular formula of pantothenic acid 75 Introduction Dietary sources tothenic acid are ingested as nutri- tional supplements, they must first be converted to pantetheine by intestin- Pantothenic acid was discovered in The active vitamin is present in vir- al enzymes before being absorbed. 1933 and belongs to the group of tually all plant, animal and microbial Topical and orally applied D-pan- water-soluble B vitamins. Its name cells. Thus pantothenic acid is widely thenol (the alcoholic form of pan- originates from the Greek word distributed in foods, mostly incorpo- tothenic acid that can, e.g., be found “pantos”, meaning “everywhere”, as rated into coenzyme A. Its richest in many cosmetic products) is also it can be found throughout all living sources are yeast and organ meats absorbed by passive diffusion and cells. (liver, kidney, heart, brain), but eggs, transformed to pantothenic acid by milk, vegetables, legumes and whole- enzymatic oxidation. The highest grain cereals are more common concentrations in the body are in the sources. liver, adrenal glands, kidneys, brain, Functions heart and testes. Total pantothenic Pantothenic acid is synthesised by acid levels in whole blood are at least Pantothenic acid, as a constituent of intestinal micro-organisms, but the 1 mg/L in healthy adults; most of it coenzyme A (a coenzyme of acetyla- extent and significance of this enteral exists as coenzyme in the red blood tion), plays a key role in the metabo- synthesis is unknown. cells. Urinary excretion in the form of lism of carbohydrates, proteins and pantothenic acid generally correlates fats, and is therefore important for with dietary intake, but variation is the maintenance and repair of all cells large (2-7 mg daily). During lactation, and tissues. Coenzyme A is involved Pantothenic acid content of foods a large proportion of the intake in reactions that supply energy, in the reaches the milk (1-5 mg daily). synthesis of essential lipids (e.g. Food Pantothenic acid sphingolipids, phospholipids), sterols (mg/100g) (e.g. cholesterol), hormones (e.g. Veal liver 7.9 Measurement growth, stress and sex hormones), Brewer’s yeast 7.2 neurotransmitters (e.g. acetylcholine), Peanuts 2.1 porphyrin (a component of haemo- Due to the fact that dietary deficiency White mushrooms 2.1 globin, the oxygen-carrying red blood is practically unknown, little research cell pigment) and antibodies, and in Egg 1.6 has been conducted through assays the metabolism of drugs (e.g. Wheat germ 1 to assess pantothenate status in sulphonamides) and in alcohol detox- Herring 0.94 man. Nutritional status can be ification. Another essential role of Milk 0.35 deduced from amounts of pantothen- pantothenic acid concerns acyl carri- Vegetables 0.2-0.6 ate excreted in urine. Less than 1 mg er protein, an enzyme involved in the daily is considered abnormally low. A synthesis of fatty acids. In the (Souci, Fachmann, Kraut) more convenient approach is deter- process of fat burning, pantothenic mination of pantothenate in serum, or acid works in concert with coenyzme preferably whole blood, by microbio- Q10 and L-carnitine. logical methods. Although these Absorption and assays are highly sensitive and specific, they are slow and tedious to Main functions in a nutshell: body stores perform. New methods, such as • Metabolism of carbohydrates, HPLC/MS (High Performance Liquid proteins and fats Most of the pantothenic acid in food Chromatography / mass spectrome- • Supply of energy from foods exists in the form of coenzyme A, and try) and immunologic methods, have • Synthesis of essential lipids, pantothenic acid is released by a also been applied. Another method sterols, hormones, neurotrans- series of enzyme reactions in the suggested for assessing nutritional mitters, and porphyrin small intestine. It is then absorbed by status is the sulphanilamide acetyla- • Metabolism of drugs and passive diffusion into the portal circu- tion test, which measures the activity alcohol detoxification lation and transported to the tissues, of coenzyme A in the blood. Whole where re-synthesis of the coenzyme blood levels typically range from 0.9 – occurs. About half of the pantothenic 1.5 µmol/L. acid in the diet is actually absorbed. If calcium pantothenate or pan- 76 Stability Deficiency Homopantothenate is a pantothenic acid antagonist that has been used in Japan to enhance mental function, Pantothenic acid is stable under neu- Since pantothenic acid occurs to especially in Alzheimer's disease. A tral conditions, but is readily some extent in all foods, it is general- rare side effect was an abnormal destroyed by heat in alkaline or acid ly assumed that dietary deficiency of brain function resulting from the fail- solutions. Up to 50% may be lost this vitamin is extremely rare. ure of the liver to eliminate toxins during cooking (due to leaching) and However, pantothenic acid deficiency (hepatic encephalopathy). This condi- up to 80% as a result of food pro- in humans is not well documented tion was reversed by pantothenic cessing and refining (canning, freez- and probably does not occur in isola- acid supplementation, suggesting it ing, milling etc.). Pasteurisation of tion but in conjunction with deficien- was due to pantothenic acid deficien- milk only causes minor losses. cies of other B vitamins. Clinical man- cy caused by the antagonist. In ifestations that can be clearly experiments with mice it has been ascribed to dietary deficiency of pan- shown that a deficiency of pan- tothenic acid have not been identi- tothenic acid leads to skin irritation Interactions fied, although it has been implicated and greying of the fur, which were in “burning feet” syndrome, a condi- reversed by giving pantothenic acid. Positive interactions tion observed among malnourished Pantothenic acid has since been Various studies have indicated that prisoners of war in the 1940s. added to shampoo, although it has vitamin B12 may aid in the conver- Deficiency symptoms have been pro- never been successful in restoring sion of free pantothenic acid into duced experimentally by administer- hair colour in humans. coenzyme A. In the absence of B12, ing the antagonist omega-methyl coenzyme A production is pantothenic acid. They include Groups at risk of deficiency decreased and fat metabolism fatigue, headaches, insomnia, nau- • Alcoholics impaired. In animal experiments, sea, abdominal cramps, vomiting and • Women on oral contraceptives ascorbic acid (vitamin C) was shown flatulence. The subjects complained • People with insufficient food intake to lessen the severity of symptoms of tingling sensations in the arms and (e.g. elderly, post-operative) due to pantothenic acid deficiency; legs, muscle cramps and impaired • People with impaired absorption vitamin A, vitamin B6, folic acid and coordination. There was cardiovascu- (due to certain internistic diseases) biotin are also necessary for proper lar instability and impaired responses utilisation of pantothenic acid. to insulin, histamine and ACTH (a stress hormone). Negative interactions Ethanol causes a decrease in the amount of pantothenic acid in tis- sues, with a resulting increase in serum levels. It has therefore been Current recommendations in the USA suggested that pantothenic acid utili- sation is impaired in alcoholics. Birth RDA* control pills containing estrogen and Infants < 6 months 1.7mg (AI) progestin may increase the require- Infants 7-12 months 1.8mg (AI) ment for pantothenic acid. The most Children 1-3 years 2mg (AI) common antagonist of pantothenic acid used experimentally to acceler- Children 4-8 years 3mg (AI) ate the appearance of deficiency Children 9-13 years 4mg (AI) symptoms is omega-methyl pan- Adults >14 years 5mg (AI) tothenic acid. L-pantothenic acid has Pregnancy 6mg (AI) also been shown to have an antago- Lactation 7mg (AI) nistic effect in animal studies. Methyl bromide, a fumigant used to control *The Dietary Reference Intakes (DRIs) are actually Allowances (RDAs). The RDA was established as vermin in places where food is a set of four reference values: Estimated Average a nutritional norm for planning and assessing stored, destroys the pantothenic acid Requirements (EAR), Recommended Dietary dietary intake, and represents intake levels of in foods exposed to it. Allowances (RDA), Adequate Intakes (AI), and essential nutrients considered to meet adequately Tolerable Upper Intake Levels, (UL) that have the known needs of practically all healthy people replaced the 1989 Recommended Dietary 77 Disease Recommended application, aerosols, tablets, oint- ments and creams). Pantethine, a prevention and Dietary Allowance derivative of pantothenic acid, is used therapeutic use (RDA) as a cholesterol and triglyceride-low- ering drug in Europe and Japan and is available in the U.S. as a dietary sup- Although isolated deficiency states are It is widely agreed that there is insuf- plement. rarely observed, various investigators ficient information available on which Pantothenate is added to a variety of have noted changes in pantothenic to base an RDA for pantothenic acid. foods, the most important of which acid levels in various diseases, and Most countries that make are breakfast cereals and beverages, pharmacological amounts of the vita- recommendations therefore give an dietetic and baby foods. min are used in the treatment of estimate of safe and adequate levels D-Panthenol is often used in cosmetic numerous conditions. In most cases, for daily intake. These adequate products. In skin care products, it however, the claimed therapeutic intake levels (AI) are based on esti- helps to keep the skin moist and sup- responses have not been confirmed mated dietary intakes in healthy pop- ple, stimulates cell growth and tissue by controlled studies in humans.