Pantothenic acid

Pantothenic acid
IUPAC name	3-[(2,4-dihydroxy-3, 3-dimethyl-1-oxobutyl) amino]propanoic acid
Identifiers
CAS number	[137-08-6]
PubChem	988
SMILES	CC(C)(CO)C(C(=O)NCCC(=O)O)O
Properties
Molecular formula	C9H17NO5
Molar mass	219.235
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Pantothenic acid, also known as vitamin B₅, is a water-soluble, yellow, oily acid in the vitamin B complex that is required to sustain life (essential nutrient). Pantothenic acid is part of the intricate coordination seen in nature, being needed to form coenzyme-A (CoA) and acyl carrier protein and thus critical in the metabolism and synthesis of carbohydrates, proteins, and fats.

Panthothenic acid's name is derived from the Greek pantothen (παντόθεν) meaning "from everywhere" and small quantities of pantothenic acid are found in nearly every food, with high amounts in whole-grain cereals, legumes, eggs, meat, and royal jelly. It is commonly found as its alcohol analog, the provitamin panthenol, and as calcium pantothenate.

Panthothenic acid is essential for proper development and well-being in humans. In addition to its role in metabolism of fatty acid, carbohydrates, and proteins, panthothenic acid is important in antibody formation, conversion of cholesterol to hormones that deal with stress, production of red blood cells, and production of the neurotransmitter acetylcholine.

Given pantothenic acid's ubiquity in foods that human beings consume, a particular dietary deficiency disease is unknown in normal circumstances. However, there can be low levels of pantothenic acid in conjunction with other vitamin deficiencies and panthothenic deficiencies can lead to burning feet syndrome, as well as a range of mental and physiological disorders.

Overview and description

Vitamins, such as pantothenic acid, are organic nutrients that are obtained through the diet and are essential in small amounts for normal metabolic reactions in humans. Panthothenic acid is part of the vitamin B complex, a group of eight, chemically distinct, water-soluble vitamins that were once considered a single vitamin (like vitamin C), but now are seen as a complex of vitamins that have loosely similar properties and generally are found in the same foods.

In chemical structure, pantothenic acid is the amide between D-pantoate and beta-alanine. It is the beta-alanie derivative of pantoic acid (Bender and Bender 2005), with the chemical formula C₉H₁₇NO₅ or CC(C)(CO)C(C(=O)NCCC(=O)O)O. It is a light-yellow, water-soluble, viscous compound.

Only the dextrorotatory (D) isomer of pantothenic acid possesses biologic activity (NSRC 2008). The levorotatory (L) form may antagonize the effects of the dextrorotatory isomer (Kimura et al. 1980).

Sources and daily requirement

Dietary sources

Small quantities of pantothenic acid are found in most foods (ARS 2005). The major food sources of pantothenic acid are meats, although the concentration found in the muscles of the food animals cattle, sheep, and pigs is only about half that in humans' muscles (Williams 2001). Some vegetables are also good sources, as well as whole grains, but a large amount of pantothenic acid is found in the outer layers of the whole grains, so the milling process removes a majority of the vitamin. In animal feeds, the most important sources of the vitamin are rice, wheat brans, alfalfa, peanut meal, molasses, yeasts, and condensed fish solutions. The most significant source of pantothenic acid in nature are coldwater fish ovaries and royal jelly (Combs 2008).

A recent study also suggests that gut bacteria in humans can generate pantothenic acid (Said et al. 1998).

Supplementation

The derivative of pantothenic acid, pantothenol, is a more stable form of the vitamin and is often used as a source of the vitamin in multivitamin supplements (Combs 2008). Another common supplemental form of the vitamin is calcium pantothenate. Pantothenate in the form of pantethine is considered to be the more active form of the vitamin in the body, but is unstable at high temperatures or when stored for long periods, so calcium pantothenate is the more usual form of vitamin B5 when it is sold as a dietary supplement. Ten milligrams of calcium pantothenate is equivalent to 9.2 milligrams of pantothenic acid. Calcium pantothenate is often used in dietary supplements because as a salt it is more stable than pantothenic acid in the digestive tract, allowing for better absorption.

While pantothenic acid and pantethine are both available as supplements, they appear to function different; pantethine can be used to lower blood cholesterol and triglycerides, while pantothenic acid supplements do not affect cholesterol, being immediately converted into coenyzmes (Turner and Frey 2005).

Possible benefits of supplementation: Doses of 2 grams per day of calcium pantothenate may reduce the duration of morning stiffness, degree of disability, and pain severity in rheumatoid arthritis patients (Turner and Frey 2005). Although the results are inconsistent, supplementation may improve oxygen utilization efficiency and reduce lactic acid accumulation in athletes (Combs 2008).

Daily requirement

A daily intake is necessary for good health, although this vitamin is found in nearly every food, and so deficiency is not known to occur under normal circumstances (Turner and Frey 2005). There is an Estimated Safe and Adequate Daily Dietary Intake in the United States that ranges from 2 milligrams for infants less than six months old to 4-7 milligrams for everyone over 11 years of age (Turner and Frey 2005).

In ruminant animals,so dietary requirement for pantothenic acid has been established as synthesis of pantothenic acid by ruminal microorganisms appears to be 20 to 30 times more than dietary amounts. Net microbial synthesis of pantothenic acid in the rumen of steer calves has been estimated to be 2.2 mg/kg of digestible organic matter consumed per day. The degradation of dietary intake of pantothenic acid is considered to be 78 percent. Supplementation of pantothenic acid at 5 to 10 times theoretic requirements did not improve performance of feedlot cattle (NRC 2001).

Absorption

Within most foods, pantothenic acid is in the form of CoA or Acyl Carrier Protein (ACP). In order for the intestinal cells to absorb this vitamin, it must be converted into free pantothenic acid. Within the lumen of the intestine, CoA and ACP are degraded from the food into 4'-phosphopantetheine. This form is then dephosphorylated into pantetheine, which is then acted upon by the intestinal enzyme, pantetheinase, to yield free pantothenic acid.

Free pantothenic acid is absorbed into intestinal cells via a saturable, sodium-dependent active transport system. At high levels of intake, when this mechanism is saturated, some pantothenic acid may also be absorbed via passive diffusion (Combs 2008).

Importance

Pantothenic acid is essential for the the synthesis of coenzyme A (CoA). Coenzyme A may act as an acyl group carrier to form acetyl-CoA, and other related compounds; this is a way to transport carbon atoms within the cell. The transfer of carbon atoms by coenzyme A is important in cellular respiration, as well as the biosynthesis of many important compounds, such as fatty acids, cholesterol, and acetylcholine.

Acetyl-CoA is used in the condensation of oxaloacetate to citrate at the initiation of the TCA cycle. From the TCA cycle, acetyl-CoA can also initiate the fatty acid synthesis pathway (Combs 2008).

Since pantothenic acid participates in a wide array of key biological roles, it is considered essential to all forms of life. As such, deficiencies in pantothenic acid may have numerous wide-ranging effects. Pantothenic acid is vital for proper growth and development and for a healthy pregnancy.

Deficiency

Pantothenic acid deficiency is exceptionally rare and has not been thoroughly studied. In the few cases where deficiency has been seen (victims of starvation and limited volunteer trials), nearly all symptoms can be reversed with the return of pantothenic acid.

Symptoms of deficiency are similar to other vitamin B deficiencies. Most are minor, including fatigue, allergies, nausea, and abdominal pain. In a few rare circumstances more serious (but reversible) conditions have been seen, such as adrenal insufficiency and hepatic encephalopathy.

It has been noted that painful burning sensations of the feet were reported in tests conducted on volunteers. Deficiency of pantothenic acid may explain similar sensations reported in malnourished prisoners of war.

Deficiency symptoms in other non-ruminant animals include disorders of the nervous, gastrointestinal, and immune systems, reduced growth rate, decreased food intake, skin lesions and changes in hair coat, alterations in lipid and carbohydrate metabolism (Smith and Song 1996).

Toxicity

Toxicity of pantothenic acid is unlikely. Large doses of the vitamin, when ingested, have no reported side effects and massive doses (for example, 10 g/day) may only yield mild intestinal distress and diarrhea at worst. There are also no adverse reactions known following parenteral or topical application of the vitamin (Combs 1998).

Disputed uses

Alternative uses of pantothenic acid have been devised, but are of disputed validity.

Hair care

Mouse models identified skin irritation and loss of hair color as possible results of severe pantothenic acid deficiency. Deficiency signs include the graying of the hair and and thus it at one time was known as the "anti-gray-hair factor." As a result, the cosmetic industry began adding pantothenic acid to various cosmetic products, including shampoo. These products, however, showed no benefits in human trials (Bender and Bender 2005). Despite this, many cosmetic products still advertise pantothenic acid additives (Novelli 1953; Schalock et al. 2000; Woolley 1941; Ishibashi 1996; Fenton et al. 1950; Bender and Bender 2005; Smith and Song 1996).

Acne

Following from discoveries in mouse trials, in the late 1990s, a small study was published promoting the use of pantothenic acid to treat acne vulgaris. According to a study by Leung (1995), high doses of Vitamin B₅ resolved acne and decreased pore size. Dr. Leung also proposes a mechanism, stating that CoA regulates both hormones and fatty-acids, and without sufficient quantities of pantothenic acid, CoA will preferentially produce androgens. This causes fatty acids to build up and be excreted through sebaceous glands, causing acne. Leung's study gave 45 Asian males and 55 Asian females varying doses of 10 to 20 grams of pantothenic acid (100,000-200,000 percent of the U.S. Daily Value), 80 percent orally and 20 percent through topical cream. Leung noted improvement of acne within one week to one month of the start of the treatment.

Critics are quick to point out flaws in Leung's study, however. The study was not a double-blind placebo controlled trial. To date, the only study looking at the effect of Vitamin B₅ on acne is Leung's, and few if any dermatologists prescribe high-dose pantothenic acid. Furthermore, there is no evidence documenting acetyl-CoA regulation of androgens instead of fatty acids in times of stress or limited availability, since fatty acids are also necessary for life.

References

ISBN links support NWE through referral fees

• Agricultural Research Service (ARS). 2005. USDA National Nutrient Database for Standard Reference, Release 18: Pantothenic acid. United States Department of Agriculture. Retrieved December 4, 2008.
• Bender, D. A., and A. E. Bender. 2005. A Dictionary of Food and Nutrition. New York: Oxford University Press. ISBN 0198609612.
• Combs, G. F. 2008. The Vitamins: Fundamental Aspects in Nutrition and Health, 3rd edition. Ithaca, NY: Elsevier Academic Press. ISBN 9780121834937.
• —. 1998. The Vitamins: Fundamental Aspects in Nutrition and Health, 2nd edition. Ithaca, NY: Elsevier Academic Press. ISBN 0121834921.
• Fenton, P. F., G. R. Cowgill, M. A. Stone, and D. H. Justice. 1950. The nutrition of the mouse, VIII. Studies on pantothenic acid, biotin, inositol and P-aminobenzoic acid. Journal of Nutrition 42(2): 257-269.
• Ishibashi, S., M. Schwarz, P. K. Frykman, J. Herz, and D. W. Russell. 1996. Disruption of cholesterol 7-hydroxylase gene in mice, I. Postnatal lethality reversed by bile acid and vitamin supplementation. J. Biol. Chem. 271(30): 18017-18023.
• Kent, M. 2002. Food and Fitness: A Dictionary of Diet and Exercise. Oxford: Oxford University Press. ISBN 0198631472.
• Kimura, S., Y. Furukawa, J. Wakasugi, Y. Ishihara, and A. Nakayama. 1980. Antagonism of L(-)pantothenic acid on lipid metabolism in animals. J Nutr Sci Vitaminol (Tokyo) 26(2): 113-7. PMID 7400861. Retrieved December 4, 2008.
• Leung, L. 1995. Pantothenic acid deficiency as the pathogenesis of acne vulgaris. Med Hypotheses 44(6): 490–2. PMID 7476595. Retrieved December 4, 2008.
• National Research Council. 2001. Nutrient Requirements of Dairy Cattle, 7th rev. ed. Washington, D.C.: Natl. Acad. Sci. ISBN 0309069971.
• Natural Standard Research Collaboration (NSRC). 2008. Pantothenic acid (vitamin B5), dexpanthenol. MedlinePlus. U.S. National Library of Medicine. Retrieved December 4, 2008.
• Novelli, G. D. 1953. Metabolic functions of pantothenic acid. Physiol Rev 33(4): 525-43.
• Said, H., A. Ortiz, E. McCloud, D. Dyer, M. Moyer, and S. Rubin. 1998. Biotin uptake by human colonic epithelial NCM460 cells: A carrier-mediated process shared with pantothenic acid. Am J Physiol 275(5 Pt 1): C1365–71. PMID 9814986. Retrieved December 4, 2008.
• Schalock, P. C., F. J. Storrs, and L. Morrison. 2000. Contact urticaria from panthenol in hair conditioner. Contact Dermatitis 43(4): 223.
• Smith, C., and W. Song. 1996. Comparative nutrition of pantothenic acid. Journal of Nutritional Biochemistry 7(6): 312-321. Retrieved December 4, 2008.
• Turner, J., and R. J. Frey. 2005. Riboflavin. In J. L. Longe, The Gale Encyclopedia of Alternative Medicine. Detroit: Thomson Gale. ISBN 0787674249.
• Williams, R. J., D. R. Davis, and M. L. Hackert. 2001. A Short History by Roger J. Williams. The Clayton Foundation Biochemical Institute. The University of Texas at Austin. Retrieved December 4, 2008.
• Woolley, D. W. 1941. Identification of the mouse antialopecia factor. J. Biol. Chem. 139(1): 29-34.

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