Dietary minerals (also known as mineral nutrients) are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. The term is archaic, as it describes chemical elements rather than actual minerals.
Minerals in order of abundance in the human body include the seven major minerals calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium. Important "trace" or minor minerals, necessary for mammalian life, include iron, cobalt, copper, zinc, molybdenum, iodine, and selenium (see below for detailed discussion).
Magnesium is an essential element in biological systems. Magnesium occurs typically as the Mg2+ ion. It is an essential mineral nutrient (i.e., element) for life and is present in every cell type in every organism. For example, ATP (adenosine triphosphate), the main source of energy in cells, must be bound to a magnesium ion in order to be biologically active. What is called ATP is often actually Mg-ATP. As such, magnesium plays a role in the stability of all polyphosphate compounds in the cells, including those associated with the synthesis of DNA and RNA.
Over 300 enzymes require the presence of magnesium ions for their catalytic action, including all enzymes utilizing or synthesizing ATP, or those that use other nucleotides to synthesize DNA and RNA.
A low sodium diet is a diet that includes no more than 1,500 to 2,400 mg of sodium per day. (One teaspoon of salt has about 2,300 mg sodium.) People who follow a vigorous or moderate exercise schedule are usually advised to limit their sodium intake to 3,000 mg per day and those with moderate to severe heart failure are usually advised to limit their sodium intake to 2,000 mg per day.]citation needed[. People who have been diagnosed with Ménière's disease, as well, need to follow a low-sodium diet.
The human minimum requirement for sodium in the diet is about 500 mg per day, which is typically less than one-sixth as much as many diets "seasoned to taste". For certain people with salt-sensitive blood pressure, this extra intake may cause a negative effect on health.