Food and nutrients provide energy and building materials for  countless substances that are essential for growth and survival of living things. Food is thus the prime necessity of life.

      The food we eat is digested and assimilated in the body and used for its maintenance and growth. The manner in which nutrients become integral part of the body and contribute to its function depends on the physiological and biochemical processes that govern their actions.

      This section opens with an overview of the processes of digestion, absorption, transportation and excretion because these functions determine the fate of the food after it enters the body. 

      Good health comprises of a sound body and a sound mind. Sound body is the outcome of food and nutrients we consume,  their digestion, absorption, and excretion. Food provides the energy and building materials for our growth and survival.

      Our food mainly consists of nutrients like proteins, carbohydrates, vitamins, minerals and fats that promote good health

      Nutritional supplements are provided when dietary needs are not met. This may occur in case of old age, pregnancy and various deficiency diseases.

      As the age progresses, absorption and utilization of nutrients decreases and supplementation becomes necessary. In case of pregnancy there is increased nutrient requirement due to the growing fetus; therefore supplements becomes necessary. In the treatment of various deficiency disease, the nutrient is provided in high doses which can be obtained by the supplement.

      However, supplementation requires continuous monitoring as it may lead to toxicity.