ABSTRACT
Minerals are found in every cell, tissue, and organ. They are important constituents of essential molecules such as thyroxine (T4), hemoglobin, and vitamin B12. They serve as critical cofactors in numerous enzymatic reactions (see Chapter 7) and form the hard mineral complexes that comprise bone (see Chapter 64). Minerals serve in the maintenance of pH, osmotic pressure, nerve conductance, muscle contraction, and in almost every aspect of life. Minerals interact such that bioavailability or use is affected.1,2 The ratios of calcium to phosphorus, iron to copper to zinc, and calcium to magnesium, and other factors are examples of such interactions. Some of these interactions are mutually benefi cial while others are antagonistic. Most of these interactions occur at the level of the gut, in that many are concerned with mineral absorption. For example, zinc absorption is impaired by high iron intakes; high zinc intake impairs copper absorption. Molybdenum and sulfur antagonize copper, and tungsten (not an essential nutrient) interferes with molybdenum absorption. These antagonisms contribute to the relative ineffi ciency of absorption of minerals that are poorly absorbed and just as poorly lost once absorbed.
