Magnesium deficiency is not very common to find. People who have severe nutrition deficiency i.e. beggars, people in jails or on ship, or starved for long time generally present it as multiple mineral deficiency syndrome. If you suspect you have Magnesium deficiency, see a physician who will advise to do some tests to check your magnesium level. Magnesium is found well in fruits and nuts like almonds, cashew etc. Magnesium prescriptions will be given by physician.