Niacin (nicotinic acid) is used in the body to make nicotinamide adenine dinucleotide (NAD) and NAD-phosphate, which supplies energy for many catabolic and anabolic reactions. Niacin will cause a transient niacin flush with redness and a burning sensation in the skin. The niacin flush is uncomfortable but harmless for most people - possible exceptions are persons with asthma or peptic ulcers. Each tablet provides 100 mg of Niacin and 56 mg of Calcium. 200 tablets per bottle.