The food you eat contains nutrients that nourish and keep you healthy. More than 40 nutrients are essential, meaning they are vital for growth and maintaining health. The term essential further denotes that your body cannot produce these nutrients and that you need a constant supply of these nutrients from food. These include carbohydrates, proteins and fats, which are required in large quantities and are referred to as macronutrients, as well as vitamins and minerals, which fall under the micronutrient category, as they are required in smaller quantities. Regardless of the quantities in which they are required, all nutrients play specific roles in the body and are equally important for health.
Source of Energy
One of the most important roles that nutrients play is as sources of energy that you need to carry out any physical activity. Energy is also required for the involuntary functions that take place incessantly such as beating of the heart, digestion of food and respiration. Although carbohydrates are the main contributors of energy in most diets, two other nutrients that also provide energy are fats and proteins. Each gram of carbohydrate provides 4 calories, which is similar to the amount provided by a gram of protein, while a gram of fat provides 9 calories. The Dietary Guidelines for Americans recommends that you obtain 45 to 65 percent of your calories from carbohydrates, 10 to 35 percent from protein and 20 to 35 percent from fat.
Energy and Protein Metabolism
Metabolism of carbohydrates, proteins and fats to release energy requires vitamin C and the B vitamins: thiamin, riboflavin, niacin, pantothenic acid, biotin, folic acid, vitamin B-6 and vitamin B-12. The vitamins help break down the complex macronutrients into their building block units. Carbohydrates are broken down to basic monosaccharide units such as glucose, proteins into amino acids and fats into fatty acids. The vitamins further aid in the release of energy from glucose, fatty acids and amino acids. However, as proteins are essential for other body functions, they are only used as a source of energy if your diet lacks carbohydrates and fats.
Growth and Development
The role of protein as a vital nutrient during periods of growth is unique, as it is an essential component of all cells, bones, tissues, cartilage, muscles, skin, hair, bones, ligaments and blood plasma. It is critical for normal growth and development. At all stages of life, protein plays an important role in the repair and maintenance of tissues and muscles and for making various hormones and enzymes. Other nutrients essential for growth, maintaining cell structure and function of cell membranes include fats, calcium, phosphorus, zinc and iodide.
Calcium and vitamin D are often the two nutrients emphasized for maintaining bone health, especially as you grow older and the risk of osteoporosis increases. However, minerals such as phosphorus, potassium, magnesium, fluoride, iron, copper, manganese, boron and zinc as well as vitamins A, K, C and the B-vitamins are equally important for healthy bones. Include milk, eggs, dairy and dairy products, fruits, vegetables, fortified breads and breakfast cereals in your diet to get adequate amounts of all these nutrients.
The role of nutrients extends to other aspects of health. Iron, copper, folate, vitamins B-6 and B-12 are vital for formation of blood, while calcium and vitamin K are essential for blood clotting. Sodium, potassium and chloride help to maintain ion balance in cells and are essential for transmission of nerve impulses. Similarly, some nutrients play a role in a healthy immune system and help fight infections, while others act as antioxidants and protect cells from damaging compounds. Eating a variety of foods every day is the best way to obtain all the nutrients essential for maintaining health.