Thursday, September 23, 2010

2.11c B3 Niacin and Pantothenic Acid

Physician's Notebooks 2  - - See Homepage 
Update 01 November 2018
2 Chapters: Niacin and Pantothenic Acid

Niacin, or Vitamin B3
Niacin (aka "vitamin B3"; and as niacinamide or nicotinic acid)  The B3 deficiency disease pellagra shows the “3 Ds” – Diarrhea, Dementia and Dermatitis – of niacin deficiency. Its signs are sunburn-red rash on exposed skin, and bright-red tongue.
   Discovered in 1735 among corn-eating Amerindians, pellagra follows introduction of corn to a poor population. Feeding niacin cures pellagra. The essential amino acid, tryptophan, can replace niacin in diet to cure pellagra.
   Good sources of niacin include red meat, fish, bean, and peanut. In the U.S., breakfast cereals, rice, bread, spaghetti, and usual supermarket foods are fortified with it.
   In experiment with volunteers on a niacin/tryptophan-free diet, it took 50-60 days for first sign of pellagra.
   Niacin speeds conversion of ethyl alcohol (EtOH) to acetate via the toxic acetaldehyde intermediate but alcohol ingestion rapidly depletes the immediately available niacin, and the resulting niacin deficiency is the cause of liver damage from the EtOH. So heavy drinkers should take niacin.
         Niacin is needed for many oxidation/reduction reactions in the body and thus needed to regenerate our body's natural anti-oxidants. Especially in the eye it helps protect the lens, cornea and retina from oxidative damage of light rays and from tetracyclines and chlorpromazine toxicity.
Niacin activates 3 other vitamins – B6 (pyridoxine), riboflavin and folic acid. So niacin deficiency, if untreated, may also put its victim at risk for the other deficiencies. Also, it is an important co-factor in the insulin response (body burning of glucose for energy) so its lack may worsen diabetes.

Biochemical Assessment of Niacin in Food and Body: 60 mg of tryptophan can substitute for 1 mg of niacin in food. Also, pyridoxine (vitamin B6) is essential for the conversion of tryptophan into niacin. Vitamin B3 measurement in food uses the niacin equivalent, or NE, by which is meant the amount of tryptophan or other niacin precursor (niacinamide and nicotinic acid), that will substitute for 1 mg niacin to relieve deficiency in test animal.

Niacin Requirement and At Risk Population: Niacin deficiency is rare in the U.S. today because of niacin fortification of food and widespread availability of low-cost niacin- or tryptophan-containing food. Special risk exists for the alcoholic, for the tuberculosis patient who uses isoniazid (INH, an anti-TB drug), and for the child with Hartnup disease, an inborn error of metabolism that needs high-dose niacin for life

Use of Niacin as Cholesterol-Lowering Drug: Niacin (But not the other forms of vitamin B3), 1.5 to 3 grams a day, a dose, more than 100 times nutritional requirement, lowers total and LDL cholesterol in blood and ups its HDL fraction, reducing risk of heart and artery disease. The treatment has high incidence of flushing with itch, and a risk of gout, diabetes, and liver damage. Today, in 2018, the Statin medicines (Lipitor, et al.) are better preventives of bad high LDL cholesterol than is niacin.
Pantothenic Acid
is widely distributed in food and only rarely involved in deficiency. Rich dietary source is liver, kidney, yeast, egg yolk, and fresh veg. Pantothenic acid in Royal Jelly from bees is popular in health stores. Experimental pantothenic deficiency in humans produces fatigue, abdominal pain and vomiting, insomnia and pins & needles tingling in fingers (Megavitamin pantothenate is claimed to cure the painful neuralgic “burning foot” syndrome); and in dogs the deficiency causes hypoglycemia (low blood sugar) with convulsion; and in rats, pantothenic deficiency resulted in loss of hair pigmentation, which has made it popular to try to prevent or reverse graying or white hair.
   Pantothenic acid has complex function; it is essential in syntheses of vitamins A and D and steroid hormones and cholesterol. It is also involved in syntheses of vitamin B12, and of hemoglobin and various important proteins.
A form of Parkinson disease with dementia related to inherited disease of high iron in the basal ganglia is Hallervorden-Spatz Disease (aka PKAN , protein kinase associated neurodegeneration, disease), and is partly prevented by high-dose pantothenate so mega-vitamin pantothenate may be worth using in Parkinson disease. (Note: the custom in 2018 is not to use Hallervorden-Spatz because those 2 scientists were implicated as Nazi's in World War 2; rather, PKAN)
Mega-dosing with PA up to 10 grams a day has caused diarrhea. No toxic upper limit (UL) has been set.
   Blood serum tests are not accurate. Best test is “pantothenate” concentration in urine and whole blood.
           Chapter Continues Next Section. To read now, click 2.11d Riboflavin and Thiamine

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