Pantothenic acid

Pantothenic acid, also called vitamin B5 (a B vitamin), is a water-soluble vitamin. Pantothenic acid is an essential nutrient. Animals require pantothenic acid in order to synthesize coenzyme-A (CoA), as well as to synthesize and metabolize proteins, carbohydrates, and fats. The anion is called pantothenate.

Pantothenic acid
Names
Preferred IUPAC name
3-[(2R)-2,4-Dihydroxy-3,3-dimethylbutanamido]propanoic acid
Systematic IUPAC name
3-[(2R)-(2,4-Dihydroxy-3,3-dimethylbutanoyl)amino]propanoic acid
Identifiers
3D model (JSmol)
3DMet
Beilstein Reference
 1727062, 1727064 (R)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.009.061
EC Number
  • 209-965-4
KEGG
MeSH Pantothenic+Acid
RTECS number
  • RU4729000
UNII
CompTox Dashboard (EPA)
Properties
C9H17NO5
Molar mass 219.237 g·mol−1
Appearance Yellow oil
Colorless crystals (Ca2+ salt)
Odor Odorless
Density 1.266 g/cm3
1.32 g/cm3 (Ca2+ salt)[1]
Melting point 183.833 °C (362.899 °F; 456.983 K)
196–200 °C (385–392 °F; 469–473 K)
decomposes (Ca2+ salt)[1][2][3]
138 °C (280 °F; 411 K)
decomposes (Ca2+ salt, monohydrate)[4]
Very soluble[5]
2.11 g/mL (Ca2+ salt)[1]
Solubility Very soluble in C6H6, ether[5]
Ca2+ salt:
Slightly soluble in alcohol, CHCl3[2]
log P −1.416[6]
Acidity (pKa) 4.41[3]
Basicity (pKb) 9.698
Chiral rotation ([α]D)
 +37.5°
+24.3° (Ca2+ salt)[3]
Hazards
NFPA 704 (fire diamond)
1
2
0
Flash point 287.3 °C (549.1 °F; 560.5 K)[4]
Lethal dose or concentration (LD, LC):
> 10 mg/g (Ca2+ salt)[2]
Related compounds
Related alkanoic acids
 Arginine
Hopantenic acid
4-(γ-Glutamylamino)butanoic acid
Related compounds
 Panthenol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Pantothenic acid is the amide between pantoic acid and β-alanine. Its name derives from the Greek pantothen, meaning "from everywhere", and small quantities of pantothenic acid are found in nearly every food, with high amounts in fortified whole-grain cereals, egg yolks, liver and dried mushrooms.[7][8] It is commonly found as its alcohol analog, the provitamin panthenol (pantothenol), and as calcium pantothenate.

Pantothenic acid was discovered by Roger J. Williams in 1933.[9]

Biological role

Only the dextrorotatory (D) isomer of pantothenic acid possesses biologic activity.[10] The levorotatory (L) form may antagonize the effects of the dextrorotatory isomer.[11]

Pantothenic acid is used in 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.[12] CoA is important in energy metabolism for pyruvate to enter the tricarboxylic acid cycle (TCA cycle) as acetyl-CoA, and for α-ketoglutarate to be transformed to succinyl-CoA in the cycle.[13] CoA is also important in the biosynthesis of many important compounds such as fatty acids, cholesterol, and acetylcholine.[13] CoA is incidentally also required in the formation of ACP,[14] which is also required for fatty acid synthesis in addition to CoA.[12]

Pantothenic acid in the form of CoA is also required for acylation and acetylation, which, for example, are involved in signal transduction, and various enzyme functions.[13] Due to its numerous biological roles, dietary deficiency of pantothenic acid, although rare and usually occurring with other nutrient deficiencies, has diverse negative effects.[8][10]

Sources

Dietary

Content of pantothenic acid varies among manufactured and natural foods, especially fortified ready-to-eat cereals, infant formulas, energy bars and dried foods.[7] Major food sources of pantothenic acid are dried shiitake mushrooms, liver, kidney, egg yolks and sunflower seeds.[7] Whole grains are another source of the vitamin, but milling removes much of the pantothenic acid, as it is found in the outer layers of whole grains.[15] In animal feeds, the most important sources are alfalfa, cereal, fish meal, peanut meal, molasses, mushrooms, rice, wheat bran, and yeasts.[16]

Supplementation

The derivative of pantothenic acid, pantothenol (panthenol), is a more stable form of the vitamin and is often used as a source of the vitamin in multivitamin supplements. Another common supplemental form of the vitamin is calcium pantothenate. Calcium pantothenate is often used in dietary supplements because, as a salt, it is more stable than pantothenic acid.[16]

Dietary recommendations

The U.S. Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for B vitamins in 1998. At that time there was not sufficient information to establish EARs and RDAs for pantothenic acid. In instances such as this, the Board sets Adequate Intakes (AIs), with the understanding that at some later date, AIs will be replaced by more exact information. The current AI for teens and adults ages 14 and up is 5 mg/day. AI for pregnancy is 6 mg/day. AI for lactation is 7 mg/day. For infants up to 12 months the AI is 1.8 mg/day. For children ages 1–13 years the AI increases with age from 2 to 4 mg/day. As for safety, the IOM sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of pantothenic acid there is no UL, as there is no human data for adverse effects from high doses. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes (DRIs).[15]

The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in the U.S. For women and men over age 11 the Adequate Intake (AI) is set at 5 mg/day. AI for pregnancy is 5 mg/day, for lactation 7 mg/day. For children ages 1–10 years the AI is 4 mg/day. These AIs are similar to the U.S. AIs.[17] The EFSA also reviewed the safety question and reached the same conclusion as in United States - that there was not sufficient evidence to set a UL for pantothenic acid.[18]

For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For pantothenic acid labeling purposes 100% of the Daily Value was 10 mg, but as of 27 May 2016 it was revised to 5 mg to bring it into agreement with the AI.[19] A table of the old and new adult Daily Values is provided at Reference Daily Intake. Food and supplement companies have until 1 January 2020 to comply with the change.[20]

Age group Age Adequate intake[15]
Infants 0–6 months 1.7 mg
Infants 7–12 months 1.8 mg
Children 1–3 years 2 mg
Children 4–8 years 3 mg
Children 9–13 years 4 mg
Adult men and women 14+ years 5 mg
Pregnant women (vs. 5) 6 mg
Breastfeeding women (vs. 5) 7 mg

Absorption

When found in foods, most pantothenic acid is in the form of CoA or bound to acyl carrier protein (ACP). 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 hydrolyzed into 4'-phosphopantetheine. The 4'-phosphopantetheine is then dephosphorylated into pantetheine. Pantetheinase, an intestinal enzyme, then hydrolyzes pantetheine into free pantothenic acid.[21]

Free pantothenic acid is absorbed into intestinal cells via a saturable, sodium-dependent active transport system.[13] At high levels of intake, when this mechanism is saturated, some pantothenic acid may also be absorbed via passive diffusion.[16] As intake increases 10-fold, however, absorption rate decreases to 10%.[13]

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.[13]

Symptoms of deficiency are similar to other vitamin B deficiencies. There is impaired energy production, due to low CoA levels, which could cause symptoms of irritability, fatigue, and apathy.[13] Acetylcholine synthesis is also impaired; therefore, neurological symptoms can also appear in deficiency;[22] they include numbness, paresthesia, and muscle cramps.[22] Deficiency in pantothenic acid can also cause hypoglycemia, or an increased sensitivity to insulin.[13] Insulin receptors are acylated with palmitic acid when they do not want to bind with insulin.[21] Therefore, more insulin will bind to receptors when acylation decreases, causing hypoglycemia.[12] Additional symptoms could include restlessness, malaise, sleep disturbances, nausea, vomiting, and abdominal cramps.[22] In a few rare circumstances, more serious (but reversible) conditions have been seen, such as adrenal insufficiency and hepatic encephalopathy.

Deficiency symptoms in other nonruminant animals include disorders of the nervous, gastrointestinal, and immune systems, reduced growth rate, decreased food intake, skin lesions and changes in hair coat, and alterations in lipid and carbohydrate metabolism.[23]

Toxicity

Toxicity of pantothenic acid is unlikely. In fact, no Tolerable Upper Level Intake (UL) has been established.[15] Large doses of the vitamin, when ingested, have no reported side effects and massive doses (e.g., 10 g/day) may only yield mild diarrhea.[13] There are also no adverse reactions known following parenteral (injected) or topical (skin) applications of the vitamin.[24] Pantothenic acid, in an animal study, was shown to induce adrenal hyper-responsiveness to stress stimulation.[25]

Research

Although pantothenic acid supplementation is under preliminary research for a variety of human diseases, there is insufficient evidence to date that it has any effect.[8][10]

Ruminant nutrition

No 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.[26]

References
  1. "Scientific Opinion on the safety and efficacy of pantothenic acid (calcium D-pantothenate and D-panthenol) as a feed additive for all animal species based on a dossier submitted by Lohmann Animal Health". EFSA Journal. Parma, Italy: European Food Safety Authority. 9 (11): 2409. 2011. doi:10.2903/j.efsa.2011.2409.
  2. "Calcium D-pantothenate". AroKor Holdings Inc. Retrieved 5 September 2014.
  3. Leenheer AP, Lambert WE, Bocxlaer JF, eds. (2000). Modern Chromatographic Analysis of Vitamins: Revised And Expanded. Chromatographic Science. 84 (3rd ed.). Marcel Dekker. p. 533. ISBN 978-0-203-90962-1.
  4. "DL-Pantothenic acid calcium salt". Retrieved 5 September 2014.
  5. Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.
  6. "MSDS of D-pantothenic acid" (PDF). Human Metabolome Database. Retrieved 5 September 2014.
  7. "Pantothenic acid ordered by nutrient content per 100 g". US Department of Agriculture National Nutrient Database. October 2016. Retrieved 25 October 2016.
  8. "Pantothenic Acid". Linus Pauling Institute at Oregon State University. Micronutrient Information Center. Retrieved 7 November 2010.
  9. Richards OW (1938). "The Stimulation of Yeast Proliferation By Pantothenic Acid" (PDF). Journal of Biological Chemistry. 113 (2): 531–536.
  10. "Pantothenic acid (Vitamin B5)". Office of Dietary Supplements, US National Institutes of Health. 9 July 2019. Retrieved 22 November 2019.
  11. Kimura S, Furukawa Y, Wakasugi J, Ishihara Y, Nakayama A (1980). "Antagonism of L(-)pantothenic acid on lipid metabolism in animals". Journal of Nutritional Science and Vitaminology. 26 (2): 113–7. doi:10.3177/jnsv.26.113. PMID 7400861.
  12. Voet D, Voet JG, Pratt CW (2006). Fundamentals of Biochemistry: Life at the Molecular Level (2nd ed.). Hoboken, NJ: John Wiley & Sons, Inc.
  13. Gropper SS, Smith JL, Groff JL (2009). Advanced nutrition and human metabolism. Belmont, CA: Wadsworth, Cengage Learning. ISBN 978-0-495-11657-8.
  14. Sweetman L (2005). "Pantothenic Acid.". In Coates PM, Blackman MR, Cragg GM, Levine MA, White JD, Moss J (eds.). Encyclopedia of Dietary Supplements. 1 (First ed.). pp. 517–525. ISBN 978-0-8247-5504-1.
  15. Institute of Medicine (1998). "Pantothenic Acid". Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: The National Academies Press. pp. 357–373. ISBN 978-0-309-06554-2. Retrieved 29 August 2017.
  16. Combs GF (2008). The Vitamins: Fundamental Aspects in Nutrition and Health (3rd ed.). Boston: Elsevier. ISBN 978-0-12-183493-7.
  17. "Overview on Dietary Reference Values for the EU population as derived by the EFSA Panel on Dietetic Products, Nutrition and Allergies" (PDF). 2017.
  18. "Tolerable Upper Intake Levels For Vitamins And Minerals" (PDF). European Food Safety Authority. 2006.
  19. "Federal Register May 27, 2016 Food Labeling: Revision of the Nutrition and Supplement Facts Labels" (PDF).
  20. "Changes to the Nutrition Facts Panel - Compliance Date"
  21. Trumbo PR (2006). "Pantothenic Acid". In Shils ME, Shike M, Ross AC, Caballero B, Cousins RJ (eds.). Modern Nutrition in Health and Disease (10th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. pp. 462–467. ISBN 978-0-7817-4133-0.
  22. Otten JJ, Hellwig JP, Meyers LD (2008). Dietary reference intakes: The essential guide to nutrient requirements. Washington, DC: The National Academies Press.
  23. Smith CM, Song WO (1996). "Comparative nutrition of pantothenic acid". Journal of Nutritional Biochemistry. 7 (6): 312–321. doi:10.1016/0955-2863(96)00034-4.
  24. Combs GF (1998). The Vitamins: Fundamental Aspects in Nutrition and Health (2nd ed.). Ithaca, NY: Elsevier Academic Press. p. 374. ISBN 978-0-12-183492-0.CS1 maint: uses authors parameter (link)
  25. Jaroenporn S, Yamamoto T, Itabashi A, Nakamura K, Azumano I, Watanabe G, Taya K (June 2008). "Effects of pantothenic acid supplementation on adrenal steroid secretion from male rats". Biological & Pharmaceutical Bulletin. 31 (6): 1205–8. doi:10.1007/s12522-011-0113-6. PMC 5906947. PMID 18520055.
  26. National Research Council (2001). Nutrient Requirements of Dairy Cattle (7th ed.). Washington, DC: National Academy of Sciences.
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