This document discusses nutrition and its role in periodontal health. It begins by defining nutrition and classifying nutrients into macronutrients and micronutrients. The roles of specific macronutrients like carbohydrates, proteins and fats are described in detail. Carbohydrates are further classified into monosaccharides, disaccharides and polysaccharides. The roles of various micronutrients like vitamins A, D and their deficiencies are also discussed. Clinical studies have shown associations between nutrition and periodontal health. Maintaining proper nutrition is important for periodontal tissue integrity and healing.