Niacin, a B vitamin, helps raise high-density lipoprotein, or HDL cholesterol, in prescription form. You can find niacin in foods or over-the-counter supplements. Niacin helps your body turn carbohydrates into energy, maintains the digestive system and keeps your nervous system under control. You can usually get the niacin you need through foods, but only prescription niacin offers high enough doses to increase HDL, known as the "good" cholesterol, the Mayo Clinic website explains.
LDL, Triglycerides and HDL
Niacin also lowers low-density lipoprotein, or LDL, known as the "bad" cholesterol, and reduces levels of triglycerides, or fats in the blood. LDL and triglycerides contribute to cholesterol and fatty buildup that leads to heart disease. Excess amounts of LDL can form plaque on the inner walls of the arteries, interfering with blood flow to the heart. Heart disease results from partially blocked arteries. When arteries become completely blocked, heart attacks and strokes can occur. HDL cleans up excess cholesterol in the bloodstream and delivers it to the liver for disposal.
Blocking Enzyme
How niacin works to raise HDL is not completely clear, but it appears to work in the liver by blocking an enzyme necessary for the production of LDL cholesterol while increasing HDL, according to the Drugs website. Niacin may suppress the release of fatty acid by fat tissues, according to the University of Michigan's Life Sciences Institute. Fatty acids help synthesize triglycerides in the liver. Lowering the release of fatty acids causes fewer fats to enter the bloodstream and HDL levels are elevated.
Removal of Fats
Niacin may suppress a pathway in the liver involving a protein that controls the speed at which triglycerides are broken down and used by tissues. Niacin may lower levels of the protein for faster removal of fats. Researchers at the Life Sciences Institute hope more research on the proteins and molecules involved in regulating fats and cholesterol in the liver can produce the benefits of niacin without the side effects.
Side Effects
Side effects of niacin include flushing that makes your skin redden and feel warm. In some cases, aspirin can counteract that effect. Other side effects may include upset stomach, headache, dizziness, increased blood sugar and liver damage, Mayo Clinic points out. Your doctor may provide the right dose to minimize side effects.
Knowing Your Levels
You need high levels of HDL and low levels of LDL and triglycerides. Harmful cholesterol and triglyceride levels have no symptoms except when heart disease symptoms occur, such as angina, which causes chest pains. A blood cholesterol test with your health-care provider can reveal your levels. Men need HDL levels at or above 40 mg per deciliter of blood, or mg/dL. Women need levels at or above 50 mg/dL. Levels below that put people at risk for heart disease.
