P hosphorus laden soft drinks can cause magnesium deficiency because phosphorus interferes with digestion. For every milligram of phosphorus contained in the soft drink 1 milligram of magnesium is destroyed. On the average, a soft drink contains approximately 30 mg of phosphorus. Toxicity symptoms include Drowsiness, weakness, and lethargy. Diarrhea is the most common and usually occurs if intake exceeds 600 mg per day.
Most foods contain magnesium, especially dairy products, fish, meat, and seafood.
Other foods that are considered good sources would include apples, apricots, avocados, bananas, blackstrap molasses, brewer's yeast, brown rice, cantaloupe, dulse, figs, garlic, grapefruit, leafy green vegetables, kelp, legumes, lemons, lima beans, millet, nuts, peaches, black-eyed peas, salmon, sesame seeds, soybeans, tofu, torula yeast, watercress, wheat, whole grains and whole grain cereals and breads. Herbal Sources Alfalfa, bladderwrack, catnip, cayenne pepper, chamomile, chickweed, dandelion, eyebright, fennel seed, fenugreek, hops, horsetail, lemon grass, licorice, mullein, nettle, oat straw, paprika, parsley, raspberry leaf, red clover, shepherd's purse, yarrow, and yellow dock. Diet, food additives and processing, absorption rate, etc. The Nutrition Desk Reference by Robert Garrison, Jr., M.A., R.Ph.