Magnesium, a component of chlorophyll, is absorbed in the small bowel by active and passive transport mechanisms. Absorption of dietary magnesium takes place mainly in the ileum. It is excreted in stool and urine, but regulation of serum magnesium is under renal control. Most renal reabsorption of magnesium occurs in the proximal tubule and the thick ascending limb of the Loop of Henle. Additionally, magnesium may be removed from bone stores in times of deficiency.
Historical complaints related to hypomagnesemia are nonspecific.
Patients may report weakness, muscle cramping, or rapid heart beats. Altered mental status may be present in severe cases. Less severe cases may result in vertigo, ataxia, depression, and seizure activity. The severity of symptoms is not related directly to the magnesium level. In one study of patients who were severely magnesium depleted, physical findings were present in only 2 of 21 patients.