MINERALS AND WATER
Minerals are inorganic substances in foods. Major minerals are needed in amounts
greater than 100 milligrams daily, trace minerals in amounts less than 100 milligrams.
Availability of any mineral in a food is influenced by the body's ability to absorb it.
Mineral absorption is determined by a number of factors including binding agents in
Minerals are divided into two groups:
. Electrolytes include
sodium, potassium, chloride, and inorganic sulfate. Electrolytes dissociate into positively
and negatively charged ions and can affect the hydrogen ion concentration in a
solution. In the human body, a difference in ionic character exists between fluid in a
cell, which is rich in potassium ions, and fluid outside a cell, which is rich in sodium
ions. Cells use energy to maintain this difference which is critical to metabolism.
Elements include calcium, phosphorous, magnesium, iron, selenium, iodine, copper,
fluoride, chromium, manganese, molybdenum, zinc and more. A diverse food supply
moderates concerns about mineral deficiency; however, calcium and iron consumption
may still be inadequate for some.
It is possible to consume too much of a mineral. Many people living in the U.S.
consume too much sodium. There are health implications for both under and
overconsumption of minerals.
Water is the most abundant substance in the human body. Total intake includes
drinking water as well as that in foods and beverages. For most adults, intake
comfortably meets needs. The minimum daily requirement depends upon diet, activity
level, and environment.
Water balance occurs when gain equals loss. Healthy people maintain balance by
excreting excess in urine. Urine volume and color suggest hydration status. Dark
colored urine suggests that a person is dehydrated. Dehydration contributes to heat
stroke. Over a short period of time, changes in body weight point to hydration status.
Physiological and psychological factors prompt drinking. It is thought that increased
water intake reduces risk of kidney stones. Recent research suggests that, contrary to