Pantothenic acid has two roles in the body:
- It is part of coenzyme A (CoA)
- It is part of acyl carrier protein
1. Coenzyme A
The structure of pantothenic acid is shown alone below and circled within coenzyme A.
Figure 10.61 The structure of pantothenic acid1
Figure 10.62 The structure of coenzyme A (CoA) with the pantothenic acid circled2
The functions of CoA are shown and described below3.
Figure 10.63 Acetyl-CoA is a central point in metabolism, and contains CoA4
Figure 10.64 CoA is used in fatty acid oxidation. The fatty acid is activated by adding CoA, forming acyl-CoA.
Figure 10.65 Fatty acid synthesis uses CoA5
2. Acyl Carrier Protein
Acyl carrier protein is also important in fatty acid synthesis3. Most pantothenic acid in food is found as CoA, which is cleaved prior to absorption. It is then taken up into the enterocyte through the sodium-dependent multivitamin transporter (SMVT) as shown below. Approximately 50% of pantothenic acid is absorbed; it is excreted primarily in urine3.
Figure 10.66 The absorption of pantothenic acid
Deficiency of pantothenic acid is very rare. Pantothenic acid supplementation did relieve the symptoms (burning feet and numbness of toes) of "burning feet syndrome" in prisoners in World War II6. It is believed pantothenic acid deficiency was the cause of this syndrome. Other symptoms noted are vomiting, fatigue, weakness, restlessness, and irritability3. No toxicity has been reported.
References & Links
- Gropper SS, Smith JL, Groff JL. (2008) Advanced nutrition and human metabolism. Belmont, CA: Wadsworth Publishing.
- Shils ME, Shike M, Ross AC, Caballero B, Cousins RJ, editors. (2006) Modern nutrition in health and disease. Baltimore, MD: Lippincott Williams & Wilkins.