Magnesium

Spices, nuts, cereals, coffee, cocoa, tea, and vegetables are rich sources of magnesium. Green leafy vegetables such as spinach are too rich in magnesium as they contain chlorophyll which is rich in magnesium.
Observations of reduced dietary magnesium intake in modern Western countries as compared to earlier generations may be related to food refining and modern fertilizers which contain no magnesium.
Low and high protein intake may inhibit magnesium absorption. Alcoholism can also produce a magnesium deficiency.
There are a number of magnesium dietary supplements available however, magnesium oxide, one of the most common because it has high magnesium content per weight, has been shown to be the least bioavailable. Magnesium citrate is a better choice.
Magnesium is the 11th most abundant element by mass in the human body; its ions play a major role in manipulating important biological polyphosphate compounds – compounds essential to production and transmission of electrical currents in the body. Due to the important interaction between phosphate and magnesium ions, magnesium ions are essential to the basic nucleic acid chemistry of life, and thus are essential to all cells of all known living organisms.
Over 300 enzymes require the presence of magnesium ions for their catalytic action, including all enzymes utilizing or synthesizing ATP, or those which use other nucleotides to synthesize DNA and RNA. ATP exists in cells normally as a chelate of ATP and a magnesium ion.
Magnesium deficiency is unfortunately very common, with only 32% of the United states meeting the required daily intake. It has been implicated in the development of a number of human illnesses such as asthma, bowel disease, epilepsy, chronic fatigue, osteoporosis, kidney stones, insomnia, ADHD and imbalances relating to the musculoskeletal and nervous system. Magnesium also appears to facilitate calcium absorption and intracellular magnesium is correlated with intracellular potassium.