Magnesium sulfate has been used specifically to lower blood pressure in pregnant women with preeclampsia, which is characterized by edema, hypertension, and hyperreflexia. These problems could become more severe and lead to seizures (then termed "eclampsia") as well. Magnesium sulfate also acts as a mild anticonvulsant in this case. Through its nerve- and muscle-relaxing effect, magnesium may be helpful in reducing epileptic seizures caused by nerve excitability.

By increasing calcium solubility, especially in the urine, magnesium can help prevent kidney stones, especially calcium oxalate stones. Research has shown this effect in a high percentage of people who form kidney stones regularly. Actually, it is thought that calcium oxalate stones are most likely to form in people who are magnesium deficient, so we may just be correcting that deficiency. Through this same effect, magnesium is helpful in preventing other tissue and blood vessel calcification (and thereby atherosclerosis), as well as some problems of the teeth, including cavities. For these purposes, a daily dose of 50 mg. of vitamin B6 and 200-300 mg. of magnesium oxide is often given.

Supplementing magnesium has been shown to be very helpful in alleviating many symptoms related to the menstrual period. Menstrual cramps, irritibility, fatigue, depression, and water retention have been lessened with magnesium, usually given along with calcium and often with vitamin B6. Magnesium is often at its lowest level during menstruation, and many symptoms of premenstrual syndrome (PMS) are relieved when this mineral is replenished. Supplementing magnesium in the same amount (or more) as calcium (about 500-1,000 mg. daily) is currently recommended for premenstrual problems.

Fatigue is often reduced with magnesium (and potassium) supplementation. The many enzyme systems that require magnesium help restore normal energy levels. Because of this function and its nerve and muscle support, magnesium may also be helpful for nervousness, anxiety, insomnia, depression, and muscle cramps. Magnesium is also given as part of a treatment for autism or hyperactivity in kids, usually along with vitamin B6. Getting children and fatigued adults to eat more green vegetables and chlorophyll is often helpful for supplying additional naturally-occurring magnesium. People tend to sleep better after taking magnesium before bed. Alcoholics tend to have low magnesium levels, and this mineral can be helpful during withdrawal and to prevent or reduce hangover symptoms.