Nutrient

A nutrient is a substance that an organism must obtain from its environment to sustain life. Nutrients provide energy, support growth and tissue maintenance, and regulate metabolism. They can be organic or inorganic, and they are needed in varying amounts. Essential nutrients are required for survival; non-essential nutrients can be produced by the body or are not strictly required in the diet.

Nutrients are commonly divided into macronutrients and micronutrients. Macronutrients are needed in larger amounts and provide energy and structural material: carbohydrates, fats, and proteins. Water is also essential and required in substantial quantities, while fiber, though not energy-yielding, is a carbohydrate with health benefits. Micronutrients are required in smaller amounts and include vitamins and minerals, which often act as cofactors in enzymatic reactions and help regulate processes such as metabolism, immunity, and bone health. Some minerals are present in trace amounts, while others are needed in greater quantities.

Nutrient intake comes from food, drink, and, in the case of plants, soil-derived minerals. Adequate and balanced nutrition supports growth, development, and health across life stages, whereas deficiencies, excesses, or imbalances can lead to disease. Nutrient science examines how nutrients interact with physiology, how diets meet dietary reference values, and how labeling and public health guidelines promote balanced consumption.