Because the four nutrients discussed above - carbohydrates, fats, proteins, and water make up the largest portion of any foodstuff by weight, they are often referred to as macronutrients. Vitamins are organic compounds that are synthesized for the most part only by plants and bacteria. Thus, our supply of vitamins must come from plant foods and our own bowel bacteria. Vita means life, and, as the name indicates, vitamins are essential for our existence. Without adequate amounts, disease can develop.
Minerals are also micronutrients, but they come from inorganic matter, primarily the earth.
Their presence in adequate amounts in our foods is also essential for our good health. They participate in thousands of metabolic reactions that must take place throughout the body. For instance, iron in the enzyme hemoglobin transports oxygen in our red blood cells. Some minerals are important elements in our structural material. Calcium, for example, is a large part of bones and teeth.