Our basic nutrients that we receive are water and glucose, proteins, fats, and vitamins. Water and glucose are used in cellular respiration within the mitochondria of cells to produce adenosine triphosphate, the basic molecular unit of energy within the human body. We need different elements like iron for our blood, calcium for our muscles and bones, and proteins that help fuel basic reactions within our bodies. Many vitamins that are essential are only fat-soluble and thus, important fats are needed. Vitamins are essential for normal growth and development and warding off diseases.