Only one type of niacin proves effective in increasing high-density lipoprotein – HDL or “good” cholesterol. It requires a prescription. Doses range from 500 mg to 3,000 mg – 3 g – depending on your doctor’s assessment. Don’t rely on niacin available in drugstores to increase your HDL. Both prescription-formula and over-the-counter varieties of niacin pose potentially serious side effects, so talk to your doctor before using niacin in any form.
Types of Niacin
Niacin – vitamin B-3 – comes in three types: niacin, niacinamide and inositol hexanicotinate. Only niacin proves effective in increasing your heart-protective HDL cholesterol. Niacinamide, commonly found in over-the-counter forms of vitamin B-3 – proves ineffective in treating HDL or LDL cholesterol. Some types of vitamin B-3 available in drugstores contain inositol hexanicotinate. It remains under study for possible use in treating cholesterol, but no evidence available in August 2011 suggests that it will work for this purpose.
HDL Cholesterol
Your HDL cholesterol protects you against cardiovascular disease by pulling triglycerides, a type of fat, and low-density lipoprotein – LDL or “bad” cholesterol – out of your arteries and shipping them to your liver for elimination. Ideally, your HDL cholesterol measures 60 mg/dl – milligrams per deciliter of blood – or higher. Women whose HDL cholesterol falls below 50 mg/dl and men whose HDL cholesterol falls below 40 mg/dl face increased risk for heart attacks and strokes. Niacin has been prescribed for more than 50 years to increase HDL levels. A doctor may prescribe niacin initially in doses of 500 mg and gradually increase the amount you take to 2,000 mg or more.
Side Effects
If you take niacin in high doses prescribed by your physician, you face both moderate and serious side effects. Niacin commonly causes flushing, a condition that turns your face and chest red and makes your skin itch, tingle and burn. Timed-release formulas of niacin reduce the risk of flushing but increase your risk for liver disease. Other relatively minor risks associated with taking niacin include headaches, nausea and vomiting. If you have kidney disease, niacin can worsen your condition and, if you have type 2 diabetes, niacin could cause unhealthy elevations in your blood sugar levels. More serious side effects include vision loss, irregular heartbeat, gastrointestinal ulcers, gout and liver damage. Niacinamide poses most of the same risks but is less likely to cause flushing. The risks of inositol hexanicotinate remain unknown.
Government Study
If you take prescription-strength niacin, it may increase your HDL cholesterol but fail to reduce your risk for cardiovascular disease. The National Institutes of Health launched a five-year, 3,400-person study to test the benefits of taking a combination of niacin and statins, another cholesterol-lowering drug, against taking only statins. Researchers canceled the trial in May 2011, 18 months early, because of safety concerns. Niacin users, as expected, realized greater improvement in their HDL levels than non-niacin users. But persons who took both niacin and statins proved just as likely to suffer heart attacks and twice as likely to suffer strokes as participants who took only statins.
