Vitamin B5

Introduction

Pantothenic acid (also known as vitamin B5) is an essential nutrient that is naturally present in some foods, added to others, and available as a dietary supplement. The main function of this water-soluble B vitamin is in the synthesis of coenzyme A (CoA) and acyl carrier protein CoA is essential for fatty acid synthesis and degradation, transfer of acetyl and acyl groups, and a multitude of other anabolic and catabolic processes. Acyl carrier protein’s main role is in fatty acid synthesis

Chemistry

•         Pantothenic acid consists of β-alanine in peptide linkage with a dihydroxy dimethyl butyric acid (‘Pantoic’ acid).

Βalanine + Pantoic acid →Pantothenic acid

•         The free acid is soluble in water and is hydrolysedby  acids/or alkalies. It is thermolabile and destroyed by heat.

Chemical Name

Pantothenic Acid

Structure

Dietary Sources

Vitamin B5 is an easy vitamin to incorporate into a good diet. It’s found in most vegetables, including:

•      broccoli
•     members of the cabbage family
•     white and sweet potatoes
•     whole-grain cereals

Other healthy sources of B5 include:

•      mushrooms
•      nuts
•     beans
•     peas
•     lentils
•     meats
•     poultry
•     dairy products
•     eggs

 

Recommended Intake

Physiological Role

■ Biochemical Role of Vitamin B5 (Pantothenic Acid)

Pantothenic acid forms a part of the molecule of coenzyme A (CoA-SH) which is concerned with the metabolism of proteins, fats and carbohydrates. Coenzyme A takes part in many physiological reactions, e.g. formation of acetyle-S-CoA and succinyl-S-CoA, in the oxidation of fatty acids and in the utilization of acetoacetic acid, synthesis of cholesterol and in many other biochemical reactions. Coenzyme A can be represented as given below.

 

In addition to forming a part of the molecule of Coenzyme A Pantothenic acid also occurs in the molecule of Acyl carrier protein (ACP) which takes part in the biosynthesis of fatty acids. Folic acid and biotin seem to be needed for the utilization of the vitamin.

Mechanism of action

Deficiency Disorders

 No deficiency disease has been recognised in man. This may be due to: Its widespread distribution in food stuffs and supply from synthesis by bacterial flora of intestines.

Deficiency manifestations observed in experimental animals are:

Dermatitis, Loss of hair (alopecia): circumocularspectacle” alopecia and graying of hairs, GImanifestations: Include gastritis and enteritis with ulceration and haemorrhagicdiarrhoea, fatty Liver develops in dogs and rats, anaemia develops in certain species and in severe cases, hypoplasia of bone marrow.

Nervous system manifestations include: Myelin degeneration of peripheral nerves and degenerative changes in posterior root ganglia.

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