These small organic molecules cannot be made in adequate amounts by the human body but are required for normal metabolism.
Minerals are essential parts of all cells.
They form the major parts of the hard tissues of the body, are necessary to mucle contraction and nervous conduction, are integral parts of the organismal and cellular respiration systems, are essential to enzyme function and are necessary to the maintnance of water and acid base balance in the body. Daily requirements are greater for children, pregnant women and under certain pathological conditions. Mineral requirements of the human can be roughly classified into macrominerals and micro or trace minerals based on the amounts required in the diet. The basic concept of the RDA has remained the same for the last 50 years and has been simply to prevent deficiencies of essential nutrients. The RDAs are sometimes changed after periodic evaluations.