Pantothenic Acid

I.  Chemical

1. Composed of pantoic acid and b-alanine joined via an amide linkage
2. Structural specificity
   1. D form is biologically active
   2. The alcohol corresponding to pantothenic acid is active in mammals
3. Synthesis of coenzyme A (Figure 9.20 from Groff et at., 1995)

II.  Functions

1. Component of Coenzyme A necessary for energy storage as well as release
   1. CoA forms this esters with carboxylic acids and can transfer acyl groups
   2. Acetyl CoA condenses with oxaloacetate to enter the tricarboxylic acid cycle
   3. Oxidative decarboxylation of pyruvate and (a-ketoglutarote requires pantothenic acid plus thiamin, riboflavin, and niacin
   4. Acetyl CoA reacts with acetoacetyl CoA in cholesterol synthesis and ketogeneses
   5. Succinyl .CoA along with glycine is necessary for the initial vitamin B₆-dependent step in her:ne synthesis
   6. Acetyl CoA condenses with activated C0₂ to form malonyl CoA in the first step in fatty acid synthesis
   7. Phospholipid and sphingomyelin production use acyl Co A
   8. Involved in protein acetylation processes which affect protein functions
2. B.  Component of 4'-phosphopantotheine
   1. Prosthetic group on acyl carier protein (ACP)
      1. ACP acts as the acyl carrier in synthesis of fatty acids
      2. ACP is a necessary component of the fatty acid synthase complex
   2. Prosthetic group of GTP synthase which converts succinyl Co A to GTP + Co A

III.  Sources

1. As its name implies (Greek pantos means everywhere), pantothenic acid is widely distributed in nature
   1. Food sources include meats, egg yolk, legumes, whole-grain cereals, and broccoli
   2. Feed sources include alfalfa hay, peanut meal, cane molasses, yeast, wheat and rice bran, and cereal seeds

IV.  Metabolism

1. Limited data. No reported absorption or transport mechanisms
2. CoA is dephosphorylated during metabolism
3. Pantothenate is excreted as such primarilyy in urine. Urinary excretion is thought to reflect dietary intake
4. Same fecal excretion occurs

V.  Requirements

1. Effect of environment
   1. Excretion of pantothenic acid is greater under hot moist conditions
2. Effect of other nutrients
   1. High protein spares requirement
   2. Vitamin B₁₂ spares pantothenic acid if diet is marginal in choline or methionine
   3. Deficiency of folic acid and biotin may interfere with utilization of pantothenic acid
3. C.  Recommended allowances
   1. Human........5-10 mg/day probably adequate. American diet contains 6-20 mg/day
   2. Swine..........4-6 mg/lb feed
   3. Poultry.........4 mg/lb feed

VI.  Deficiency

1. Human
   1. Burning feet syndrome - abnormal skin sensations in feet and lower legs
      1. Exacerbated by warmth
      2. Diminished with cold
   2. Vomiting, fatigue, weakness
   3. Deficiency associated with:
      1. Alcoholism (decreased intake)
      2. Diabetes mellitus (increased excretion)
      3. Inflammatory bowel diseases (impaired absorption)
2. Swine
   1. Alopecia, atrophy of epidermis, loss of hair follicles
   2. Diarrhea, sometimes containing mucous or blood
   3. Mucosa diffusely hyperemic and slightly edematous
   4. Gait resembling "goose-step"
   5. Extensive changes in intestine, especially color
   6. Adrenal enlargement
   7. Nerve degeneration
3. Chicken
   1. Dermatitis, eyelids stick together, scabs on mouth, vent, and feet
   2. Liver damage
   3. Changes in spinal cord

VII.  Toxicity

1. Has not been reported in humans
   1. Intakes above 100 mg may increase niacin excretion
   2. Intakes up to 10 g for up to 6 weeks caused no problems
   3. Intakes up to 20 g may cause wild intestinal distress and diarrhea

Pantothenic acid (Vitamin B5) — C₉H₁₇NO₅

Part of coenzyme A — the helper that carries two-carbon pieces when you burn fat and make some hormones. Most mixed diets already contain it.

Vitamins, Major Elements, Trace Elements, Toxic Elements

Vitamins

Vitamin A	Vitamin B1 (Thiamin)	Vitamin B2 (Riboflavin)	Vitamin B3 (Niacin)
Vitamin B5 (Pantothenic Acid)	Vitamin B6	Vitamin B12	Vitamin C
Vitamin D	Vitamin E	Vitamin K	Biotin
Folic Acid

Major Elements

Calcium	Magnesium	Phosphorus	Sodium, Potassium, Chloride
Sulfur (Sulfer)

Trace Elements

Boron	Chromium	Cobalt	Copper
Fluorine	Iodine	Iron	Manganese
Molybdenum	Nickel (Nickle)	Selenium	Silicon
Tin	Vanadium	Zinc	Ultra Trace

Toxic Elements

Aluminum	Arsenic	Cadmium	Lead
Mercury