Potassium and magnesium belong to the class of minerals known as macrominerals. For normal function, your body requires large quantities of several macrominerals, including potassium, magnesium, chloride and calcium. Potassium and magnesium are required for normal heart and neurologic function as well as many enzymatic processes. Alterations in potassium and magnesium levels can lead to significant health effects.
Muscle contractions, nervous system activity and several basic cell functions rely on normal potassium levels. Many enzymes depend on magnesium for normal function and activation. All enzymatic processes involving energy production by your body rely on magnesium, according to the Merck Manuals Online Medical Library. Magnesium levels are also related to balance of other electrolyte levels including potassium and calcium.
Potassium and magnesium levels in your body can be determined by directly measuring concentrations in either the blood or urine. Due to the close relationship with other electrolytes, magnesium levels in the blood should be interpreted with other electrolyte levels as can be determined in standard larger blood electrolyte panels. Urine tests may be utilized to measure levels of potassium excretion in cases of dehydration as well as to determine levels of kidney function.
Most of the potassium in your body can be found inside your cells. Low levels of potassium leads to secretion of the hormone aldosterone from the adrenal glands into the blood. Aldosterone regulates potassium excretion by the kidney to maintain normal levels in your blood between 3.7 to 5.2 milliequivalents per liter, according to MedlinePlus.
The adult body contains approximately 2,000 milliequivalents of magnesium, making it the fourth most abundant electrolyte in your body. About half of the magnesium in your body can be found in your bones. The remaining magnesium is mostly confined to the inside of your cells, with very little present in the blood. Normal magnesium levels in the blood range from 1.4 to 2.1 milliequivalents per liter, states the Merck Manuals. The kidneys and gastrointestinal tract control magnesium absorption and excretion to maintain normal levels.
Low levels of potassium can cause muscle twitches or cramps and abnormal heart rhythms. A high potassium level represents a more dangerous condition and can cause significant abnormal heart rhythms. Low levels of magnesium cause loss of appetite, nausea, vomiting, weakness, lethargy and neurological effects, including personality change. High levels of magnesium can cause respiratory depression and cardiac arrest.