Nicotinic acid is the chemical name for vitamin B-3, also known as niacin. High doses of nicotinic acid can alter the levels of fats in your bloodstream. Triglycerides, total cholesterol and LDL typically decrease in response to high-dose nicotinic acid therapy. Although nicotinic acid is available over-the-counter as a dietary supplement, do not take high doses of this product without your doctor's supervision, because serious side effects may occur.
Mechanism of Action
Your liver packages cholesterol and triglycerides into protein carriers, forming lipoproteins. Fats travel in your bloodstream in the form of different types of lipoproteins. LDL, also known as low-density lipoprotein or "bad" cholesterol, carries high concentrations of cholesterol and triglyceride. High doses of nicotinic acid reduce the production of the precursor of LDL in your liver, a substance called VLDL. The reduced production of VLDL in the liver leads to a reduction in the triglyceride and LDL levels in your bloodstream.
Indication
Your LDL level significantly affects your risk of developing coronary heart disease. An elevated LDL level increases the probability that cholesterol deposits will form in the blood vessels that supply your heart, putting you at risk for a heart attack. If your LDL level is elevated, your doctor is likely to initially recommend increased physical activity, weight loss, reduced dietary fat intake and increased consumption of dietary fiber. If these measures do not sufficiently lower your LDL level, medications are usually added to the treatment plan. High-dose nicotinic acid is one of the medications your doctor may recommend to lower your LDL, triglyceride and total cholesterol levels.
Dose and Effect
Your daily nutritional need for nicotinic acid is approximately 15 mg. The amount required to lower your LDL and triglyceride levels is roughly 100 times greater. Depending on whether your doctor prescribes an immediate, extended or sustained release preparation, the dose of nicotinic acid required to lower your blood fat levels is 1,000 to 3,000 mg daily. High-dose nicotinic acid can potentially lower your triglyceride level by 20 to 50 percent and your LDL level by 5 to 25 percent.
Potential Side Effects
High doses of nicotinic acid can cause a variety of side effects, ranging from mild to serious. Skin flushing and itching commonly occur when beginning nicotinic acid therapy and typically decrease in severity over time. Heart rhythm abnormalities and low blood pressure also occur in some patients. Vomiting, diarrhea and the development of ulcers are other potential side effects of high-dose nicotinic acid. If you are diabetic, nicotinic acid therapy may lead to difficulty controlling your blood sugar level. Rarely, serious liver disease can develop while on high doses of nicotinic acid. Stay in close communication with your doctor while on nicotinic acid therapy and report any new symptoms that develop.
References
- National Heart Lung and Blood Institute: National Cholesterol Education Program, Nicotinic Acid
- Lipids Online: Nicotinic Acid: Mechanism of Action
- Institute of Medicine of the National Academies, Food and Nutrition Board: Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals
- National Heart Lung and Blood Institute: National Cholesterol Education Program, Drugs Affecting Lipoprotein Metabolism
- Drugs.com: Niacor, FDA Monograph
- American Heart Association: Cholesterol-Lowering Drugs
