Niacinamide is a water-soluble vitamin, or B complex vitamin. It helps the skin to maintain its own moisture and is important for healthy hair, nails, and skin.  Best Niacinamide Serum in India, also known as nicotinamide, is a form of vitamin B3. It is found in many foods and can be taken as a supplement. Niacinamide has many health benefits and can be used to treat a variety of conditions.