It’s no surprise that lack of magnesium may be the cause of frequent migraines. Experts agree that 75 percent of adults in the U.S. lack magnesium. Magnesium works by relaxing the nerves and muscles throughout the brain and body. For best results, take a daily supplement of magnesium citrate or magnesium oxide. You can also add magnesium rich foods to your diet by eating more spinach, Swiss chard, black beans and Alaskan salmon. These are only a few of many magnesium rich foods.