Probably been covered a hundred times but if it can help someone else here's what I 've learned of late. High intakes of Vitamin D dramatically increase need for Mg. Stress of surgery and anesthetics deplete Mg. stores-- Almost everyone is deficient- oral intake isn't well absorbed. According to Carolyn Dean, Md Nd, one of the best ways to restore Mg. levels is transdermal Mg. chloride, and a highly micronized oral Mg. chloride solution. Mg. is involved in hundreds of enzymes in human physiology and the need is far greater than for Calcium supplements. When I scrolled down the list of posts, some literally screamed Mg. deficiency-- rapid heartbeat--palpitations- fatigue(many causes), but bear in mind Mg. is a big player in ATP production AND mitochondrial detoxification. If any of you are disciples of Sherry Rogers you'll know how much she promotes Mg. and detox for more energy/less fatigue Did I mention blood pressure issues? If not Mg. plays a role here as well as it controls vascular and large muscle tension as well as sodium transfer across membranes. Hopefully this shines some light for someone struggling with insomnia and muscle twitches, digestive issues(Mg plays a role in production of hydrochloric acid- think nutrient absorption) and a plethora of other easily identifiable and FIXABLE problems.