br Vitamin B3 is available in three forms: nicotinic acid (also called nicotinate) and niacinamide (also called nicotinamide), both found in food and supplements; and inositol hexaniacinate, a form available only in supplements. Nicotinic acid and inositol hexaniacinate are both useful in reducing blood cholesterol levels. Niacinamide is helpful for some people with insulin-dependent diabetes and perhaps for arthritis sufferers.