Pantothenic acid

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Pantothenic acid
General
Systematic name	3-[(2R,4-dihydroxy-3,3-dimethyl- butanoyl)amino]propanoic acid
CAS number	Calcium Pantothenate (CAS: 137-08-6)
Molecular formula	C9H17NO5
SMILES	CC(C)(CO)C(C(=O)NCCC(=O)O)O
Molar mass	219.235 g/mol
Infobox disclaimer and references

Pantothenic acid, also called vitamin B₅, is a water-soluble vitamin required to sustain life. Pantothenic acid is needed to form coenzyme-A (CoA), and is critical in the metabolism and synthesis of carbohydrates, proteins, and fats. Chemically it is the amide between D-pantoate and beta-alanine. Its 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.

Contents 1 Biologic role 2 Sources 3 Daily requirement 4 Deficiency 5 Disputed uses 5.1 Hair care 5.2 Acne 6 Synonyms 7 See also 8 Enzymes 9 References 10 External links

[edit] Biologic role

Only the dextrorotatory (D) isomer of pantothenic acid possesses biologic activity. ^[1] The levorotatory (L) form may antagonize the effects of the dextrorotatory isomer.^[2]

Pantothenic acid is used in the synthesis of coenzyme A (abbreviated as 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.

Since pantothenic acid participates in a wide array of key biological roles, it is considered essential to all forms of life^[3]. As such, deficiencies in pantothenic acid may have numerous wide-ranging effects, as discussed below.

[edit] Sources

Small quantities of pantothenic acid are found in most foods [2], with high quantities found in whole grain and eggs. Pantothenic acid can also be found in many dietary supplements (as calcium-D-pantothenate), and some energy drink companies are now adding pantothenic acid to their beverages.

A recent study also suggests that gut bacteria in humans can generate pantothenic acid^[4].

[edit] Daily requirement

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. 10 mg of calcium pantothenate is equivalent to 9.2 mg of pantothenic acid.

Age group	Age	Requirements (in mg per day)
infants	0-6 months	1.7
infants	7-12 months	2
children	4-8 years	3
children	9-13 years	4
adolescents	14-18 years	5
adults	19 years and older	5
pregnant women		6
breastfeeding women		7

• United Kingdom RDA: 6 mg/day

[edit] 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.

Notably, 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^[3].

[edit] Disputed uses

Given pantothenic acid's prevalence among living things and the limited body of studies in deficiency, many "alternative" uses of pantothenic acid have been devised.

[edit] Hair care

Mouse models identified skin irritation and loss of hair color as possible results of severe pantothenic acid deficiency. 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. Despite this, many cosmetic products still advertise pantothenic acid additives.

[edit] Acne

Following from discoveries in mouse trials^{[citation needed]}, in the late 1990s a small study was published promoting the use of pantothenic acid to treat acne vulgaris.

According to a study published in 1995 by Dr. Lit-Hung Leung^[5], 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.^{[citation needed]} This causes fatty acids to build up and be excreted through sebaceous glands, causing acne.^{[citation needed]} Leung's study gave 45 Asian males and 55 Asian females varying doses of 10-20g of pantothenic acid (100,000%-200,000% of the US Daily Value), 80% orally and 20% through topical cream. Leung noted improvement of acne within one week to one month of the start of the treatment.^{[citation needed]}

Critics are quick to point out the flaws in Dr. Leung's study, however. Dr. Leung's study was not a double-blind placebo controlled trial. To date, the only study looking at the effect of Vitamin B₅ on acne is Dr. 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.

Today, many companies offer Vitamin B₅ supplements aimed at reducing acne. The recommended treatment course, however, can be perceived as difficult and expensive. Many sites suggest starting off the first three days with 5g and then moving up to 10g a day for three months. Since the largest pill available is 1g, this can result in as many as 10 pills a day or more if smaller pills are taken. The average cost for a bottle of 200 B₅ 500mg tablets is $10, so the cost can be steep. B₅ sold as a powder that can be dissolved in water and drunk is generally a cheaper and for some people a more convenient alternative. Furthermore, after three months many users suggest decreasing to 3-5g a day, with some claiming 1 g/day is sufficient.

[edit] Synonyms

• pantothenate
• vitamin B5
• Vilantae-a brand name for the supplement when used to treat acne.

[edit] See also

• Coenzyme A
• Panthenol

[edit] Enzymes

• Ketopantoate hydroxymethyltransferase

[edit] References

1. ^ MedlinePlus. "Pantothenic acid (Vitamin-B5), Dexpanthenol". Natural Standard Research Collaboration. U.S. National Library of Medicine. Last accessed 4 Jan 2007. [1]
2. ^ Kimura S, Furukawa Y, Wakasugi J, Ishihara Y, Nakayama A. Antagonism of L(-)pantothenic acid on lipid metabolism in animals. J Nutr Sci Vitaminol (Tokyo). 1980;26(2):113-7. PMID 7400861.
3. ^ ^{a b} Jane Higdon, "Pantothenic Acid", Micronutrient Information Center, Linus Pauling Institute
4. ^ Said H, Ortiz A, McCloud E, Dyer D, Moyer M, Rubin S (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. 
5. ^ Leung L (1995). "Pantothenic acid deficiency as the pathogenesis of acne vulgaris". Med Hypotheses 44 (6): 490-2. PMID 7476595. 

[edit] External links

• PDRhealth.com - Pantothenic acid
• Pantothenate at Klotho
• An Overview of the B5 Vitamin
• Reference link to Coenzyme-A and acne
• Pantothenic acid and acne
• Links to external chemical sources