Nicotinic acid and niacinamide -- two forms of vitamin B-3 -- both appear naturally in foods such as peanuts, fish, beets and sunflower seeds. Foods that contain tryptophan -- turkey, chicken and eggs, for example -- convert to vitamin B-3 in your body. Vitamin B-3 obtained from dietary sources improves liver function, helps you metabolize food and helps keeps your hair, skin and eyes healthy. In pill form, nicotinic acid and niacinamide provide separate and distinct benefits, but similar risks.
Nicotinic Acid Benefits
Nicotinic acid, the formal name for niacin, requires a prescription. If you purchase products labeled vitamin B-3 or niacin as an over-the-counter supplement, it will not contain nicotinic acid. Nicotinic acid is the only form of vitamin B-3 proven effective in lowering cholesterol. It works to reduce levels of low-density lipoprotein, the "bad" cholesterol, and triglycerides, a type of artery-clogging fat. It also helps increase your levels of heart-friendly high-density lipoprotein, the "good" cholesterol that pulls LDL cholesterol and triglycerides out of your system. Nicotinic acid also helps relieve arteriosclerosis, informally called "hardening of the arteries."
Niacinamide Benefits
Niacinamide does not improve your cholesterol levels or clear plaque buildup that causes arteriosclerosis. It may, however, delay the progression of Type 1 diabetes -- extend the time between diagnosis of the disease and your need to take insulin. It may also help relieve joint pain and increase mobility if you have osteoarthritis. But you should not self-medicate for these conditions with over-the-counter niacinamide. If you purchase vitamin B-3 supplements, they may contain a third type of the vitamin -- inositol hexanicotinate. The effectiveness and safety of inositol remains under study.
Skin Flushes
Nicotinic acid proves more likely than niacinamide to cause a side effect called skin flushes. The harmless condition causes your face and chest to turn red and produce uncomfortable symptoms such as itching, burning and tingling of your skin. If you're taking nicotinic acid, several options exist to reduce the likelihood or severity of skin flushes: take an aspirin 30 minutes before your dose, take small doses of nicotinic acid until your body adjusts to the medication or switch to a timed-release formula of nicotinic acid.
Side Effects
Both nicotinic acid and niacinamide may cause liver damage. Your risk increases at higher doses and with extended use. Timed-release formulas of nicotinic acid increase the risk of liver damage. The recommended daily allowance of vitamin B-3 ranges from 14 mg a day for women and 16 mg a day for men. Prescription formulas of nicotinic acid may contain up to 3,000 mg -- 3 g -- of vitamin B-3 and niacinamide supplements may contain 500 mg. You may experience side effects at doses higher than 50 mg to 100 mg daily. Moderate side effects include vomiting, diarrhea, headaches and nausea. If you have Type 2 diabetes, nicotinic acid and niacinamide may cause dramatic elevations in your blood glucose levels. Both forms of vitamin B-3 may also worsen symptoms of kidney disease as well as cause gout, stomach ulcers and vision loss. In May, 2011, the National Institutes of Health halted a niacin study 18 months early amid safety concerns. People in the study who took 2,000 mg of nicotinic acid daily had improved cholesterol levels but suffered more than twice as many strokes as study participants who did not take nicotinic acid.
