Vitamin B-3, also known as niacin, is one of eight B vitamins. It plays a role in converting the food we eat into energy. It helps the body to use proteins and fats, and it keeps the skin, hair, and nervous system healthy. The video tells us about functions, benefits, sources, and deficiency of Niacin. Pellagra is well discussed in the provided video. TIMELINE: 0:00 Introduction 0:37 Functions of Niacin 1:07 Benefits of Niacin 1:44 Sources of Niacin 1:56 Deficiency cause 2:26 Enzymes that need Niacin 4:55 Pellagra 5:46 Clinical pearls 5:59 Prevelance and symptoms of deficiency 7:51 Diagnosis and treatment 8:11 Conclusion points