• Niacin, Niacinamide, Nicotinamide, Inositol Hexaniacinate
• Inositol Hexaniacinate:
Vitamin B 3 is required for the proper function of more than 50 enzymes. Without it, your body would not be able to release energy or make fats from carbohydrates. Vitamin B 3 is also used to make sex hormones and other important chemical signal molecules.
Vitamin B 3 comes in two principal forms: niacin (nicotinic acid) and niacinamide (nicotinamide). When taken in low doses for nutritional purposes, these two forms of the vitamin are essentially identical. However, each has its own particular effects when taken in high doses. Additionally, a special form of niacin called inositol hexaniacinate has shown some promise as a treatment with special properties of its own.
The official US and Canadian recommendations for daily intake of niacin are as follows:
- 0-6 months: 2 mg
- 7-12 months: 4 mg
- 1-3 years: 6 mg
- 4-8 years: 8 mg
- 9-13 years: 12 mg
- 14 years and older: 16 mg
- 14 years and older: 14 mg
- Pregnant Women : 18 mg
- Nursing Women : 17 mg
Because the body can make niacin from the common amino acid tryptophan, niacin deficiencies are rare in developed countries. However, the antituberculosis drug isoniazid (INH) impairs the body's ability to produce niacin from tryptophan and may create symptoms of niacin deficiency. 1,2
Good food sources of niacin are seeds, yeast, bran, peanuts (especially with skins), wild rice, brown rice, whole wheat, barley, almonds, and peas. Tryptophan is found in protein foods (meat, poultry, dairy products, fish). Turkey and milk are particularly excellent sources of tryptophan.
When used as therapy for a specific disease, niacin, niacinamide, and inositol hexaniacinate are taken in dosages much higher than nutritional needs, about 1 to 4 g daily. Because of the risk of liver inflammation at these doses, medical supervision is essential.
Many people experience an unpleasant flushing sensation and headache when they take niacin. These symptoms can usually be reduced by gradually increasing the dosage over several weeks or by using slow-release niacin. However, slow-release niacin appears to be more likely to cause liver inflammation than other forms. Inositol hexaniacinate may also cause less flushing than plain niacin, and if you take an aspirin along with niacin, the flushing reaction will usually decrease.
There is no question that niacin (but not niacinamide) can significantly improve
profile, reducing levels of total and LDL ("bad") cholesterol and raising HDL ("good") cholesterol.
Niacinamide may improve blood sugar control in both children and adults who already have diabetes.
niacinamide has shown some promise for skin conditions. In a double-blind study of 50 women with signs of
In addition, weak and in some cases contradictory evidence suggests one of the several forms of niacin might be helpful for people with
A new use of niacin was reported in 2007: it appears that some people take very high doses of niacin (in the neighborhood of 2.5 to 5 grams at a time ) in the belief that it will mask drugs in the urine.
What Is the Scientific Evidence for Vitamin B 3 ?
Niacin is one of the best researched of all the vitamins, and the evidence for using it to treat at least one condition—high cholesterol—is strong enough that it has become an accepted mainstream treatment.
Niacin has been used since the 1950s to improve
profile. Several well-designed
Niacin appears to be a safe and effective treatment for high cholesterol in people with diabetes as well, and (contrary to previous reports) does not seem to raise blood sugar levels.
When a child develops diabetes, there is an interval called the honeymoon period in which the pancreas can still make some insulin and there is little to no need for injected insulin. Weak evidence suggests that niacinamide might slightly delay the onset of more severe symptoms.
A recent study suggests that niacinamide may also improve blood sugar control in type 2 (adult-onset) diabetes, but it did not use a double-blind design.
Double-blind studies involving a total of about 400 individuals have found that inositol hexaniacinate can improve walking distance for people with
There is some evidence that niacinamide may provide some benefits for those with
When taken at a dosage of more than 100 mg daily, niacin frequently causes annoying skin flushing, especially in the face, as well as stomach distress, itching, and headache. 65
A more dangerous effect of niacin is liver inflammation. Although some reports suggest that it occurs most commonly with slow-release niacin, it can occur with any type of niacin when taken at a daily dose of more than 500 mg (usually 3 g or more). Regular blood tests to evaluate liver function are, therefore, mandatory when using high-dose niacin (or niacinamide or inositol hexaniacinate). This reaction almost always goes away when niacin is stopped. Note : Contrary to claims on some manufacturer's websites, there is no reliable evidence that inositol hexaniacinate is safer than ordinary niacin.
As noted above, a single dose of 2.5 to 5 grams of niacin (used in the vain hope of passing a urine drug test despite the presence of drugs in the system) can cause life-threatening disturbances in body function.
If you have liver disease, ulcers (presently or in the past), gout, or drink too much alcohol,
While there has been some concern that niacin may raise blood sugar levels in diabetics, the effect appears to be slight, and it carries little, if any, clinical significance.
Combining high-dose niacin with statin drugs (the most effective medications for high cholesterol) further improves cholesterol profile by raising HDL (“good”) cholesterol.
A growing body of evidence, however, suggests that the risk is relatively slight in individuals with healthy kidneys. Furthermore, even much lower doses of niacin than the usual dose given to improve cholesterol levels (100 mg versus 1,000 mg or more) may provide a similar benefit.
Nonetheless, it is not safe to try this combination except under close physician supervision. Rhabdomyolysis can be fatal.
Another potential drug interaction involves the anticonvulsant drugs
The maximum safe dosage of niacin for pregnant or nursing women has been set at 35 mg daily (30 mg if 18 years old or younger).
Interactions You Should Know About
If you are taking:
- Cholesterol-lowering drugs in the statin
If you drink alcohol excessively:
- Do not take niacin except under physician supervision.
6. Lal SM, Hewett JE, Petroski G, et al. Effects of nicotinic acid and lovastatin in renal transplant patients: a prospective, randomized, open-labeled crossover trial. Am J Kidney Dis . 1995;25:616-622.
9. Elam MB, Hunninghake DB, Davis KB, et al. Effect of niacin on lipid and lipoprotein levels and glycemic control in patients With diabetes and peripheral arterial disease. The ADMIT Study: a randomized trial. JAMA. 2000;284:1263-1270.
10. Morgan JM, Capuzzi DM, Guyton JR, et al. Treatment effect of Niaspan, a controlled-release niacin, in patients with hypercholesterolemia: A placebo-controlled trial. J Cardiovasc Pharmacol Ther . 1996;1:195-202.
13. Polo V, Saibene A, Pontiroli AE. Nicotinamide improves insulin secretion and metabolic control in lean type 2 diabetic patients with secondary failure to sulphonylureas. Acta Diabetol . 1998;35:61-64.
21. Tang AM, Graham NHM, Kirby AJ, et al. Dietary micronutrient intake and risk of progression to acquired immunodeficiency syndrome (AIDS) in human immunodeficiency virus type 1 (HIV-1)-infected homosexual men. Am J Epidemiol. 1993;138:937-951.
23. Kunin RA. Manganese and niacin in the treatment of drug-induced tardive dyskinesias. J Orthomol Psychiatry 5:4-27, 1976. In: Werbach MR. Nutritional Influences on Illness [book on CD-ROM]. 2nd ed. Tarzana, CA; 1996.
27. Lal SM, Hewett JE, Petroski G, et al. Effects of nicotinic acid and lovastatin in renal transplant patients: a prospective, randomized, open-labeled crossover trial. Am J Kidney Dis . 1995;25:616-622.
28. Elam MB, Hunninghake DB, Davis KB, et al. Effect of niacin on lipid and lipoprotein levels and glycemic control in patients With diabetes and peripheral arterial disease. The ADMIT Study: a randomized trial. JAMA . 2000;284:1263-1270.
29. Morgan JM, Capuzzi DM, Guyton JR, et al. Treatment effect of Niaspan, a controlled-release niacin, in patients with hypercholesterolemia: a placebo-controlled trial. J Cardiovasc Pharmacol Ther . 1996;1:195-202.
31. Elam MB, Hunninghake DB, Davis KB, et al. Effect of niacin on lipid and lipoprotein levels and glycemic control in patients With diabetes and peripheral arterial disease. The ADMIT Study: a randomized trial. JAMA. 2000;284:1263-1270.
35. Ludvigsson J, Samuelsson U, Johansson C, et al. Treatment with antioxidants at onset of type 1 diabetes in children: a randomized, double-blind placebo-controlled study. Diabetes Metab Res Rev . 2001;17:131-136.
36. Polo V, Saibene A, Pontiroli AE. Nicotinamide improves insulin secretion and metabolic control in lean type 2 diabetic patients with secondary failure to sulphonylureas. Acta Diabetol . 1998;35:61-64.
46. Elam MB, Hunninghake DB, Davis KB, et al. Effect of niacin on lipid and lipoprotein levels and glycemic control in patients With diabetes and peripheral arterial disease. The ADMIT Study: a randomized trial. JAMA . 2000;284:1263-1270.
51. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B 6 , Folate, Vitamin B 12 , Pantothenic Acid, Biotin, and Choline (1998). The National Academies Press website. Available at http://www.nap.edu . Accessed October 4, 2001.
56. Grundy SM, Vega GL, McGovern ME, et al. Efficacy, safety, and tolerability of once-daily niacin for the treatment of dyslipidemia associated with type 2 diabetes: results of the assessment of diabetes control and evaluation of the efficacy of niaspan trial. Arch Intern Med . 2002;162:1568-1576.
68. Gale EA, Bingley PJ, Emmett CL, et al. European Nicotinamide Diabetes Intervention Trial (ENDIT): a randomised controlled trial of intervention before the onset of type 1 diabetes. Lancet . 2004;363:925-931.
69. Cabrera-Rode E, Molina G, Arranz C, et al. Effect of standard nicotinamide in the prevention of type 1 diabetes in first degree relatives of persons with type 1 diabetes. Autoimmunity. 2006;39:333-340
Last reviewed April 2009 by EBSCO CAM Review Board
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