Unlike niacin, magnesium does have a few well-controlled, randomized trials indicating its efficacy in migraine prevention. One study of oral magnesium oxide supplementation found that a dose of 600 mg daily over twelve weeks significantly decreased the frequency of migraine attacks. Other small but well-designed studies have found that magnesium supplementation may also be a safe and effective prophylactic therapy for children, and for women suffering from menstrual migraine.
Intravenous magnesium sulfate has shown promise as an acute therapy for migraines in progress. One small 2001 study found that the treatment eliminated head pain in 86 percent of the patients studied. Another study of emergency room treatment in migraineurs found that intravenous administration of magnesium sulfate was just as effective in reducing migraine head pain as IV infusion of metoclopramide.
How does magnesium work? The mineral helps to regulate serotonin and other neurotransmitter function, and promotes muscle relaxation, among other things.
Research suggests that migraineurs have lower levels of magnesium in the body than most people, which could explain the mineral's effectiveness in migraine treatment.
The best way to get essential vitamins and minerals is through a varied and healthy diet. The vitamins and minerals found in your food are better absorbed than supplements, taste better, and are cheaper in the long run.
A deficiency of magnesium can actually cause headache and sensitivity to light, which could explain its effectiveness in migraine treatment. Magnesium deficiency is not a common condition and occurs most often in people who have a malabsorption problem (problems absorbing nutrients from food), in chronic alcoholics, and as a side effect of certain medications. People with a calcium deficiency may also have a related magnesium deficiency.
Poor nutrition also has the ability to affect magnesium levels in the body. High sugar, fat, and phosphate intake through processed foods can affect the absorption of magnesium. Red meat, green leafy vegetables, and whole grain cereals are all good dietary sources of magnesium.
Some foods rich in magnesium may also be a trigger for migraine in some people. Almonds, cashews, soybeans, and seafood are all abundant sources of magnesium, but have been reported to trigger attacks in some migraineurs.
Oral magnesium supplements can cause gastrointestinal distress at high doses — including nausea, bloating, and diarrhea. When taken as a supplement at levels high above recommended dosage, magnesium can be toxic to the body. Symptoms of a magnesium supplement overdose include erratic heartbeat, skin flushing, dizziness, confusion, muscle weakness, and loss of consciousness. Excess magnesium taken in dietary form does not cause side effects because the body excretes it naturally.