While magnesium tends to come up on podcasts in the context of improving sleep or supporting healthy muscle function, the mineral actually plays a vital, much broader role in all kinds of bodily functions across the nervous, endocrine, cardiovascular, and musculoskeletal systems, says Daniel Chavez, RD, CSCS, a registered dietician at Fay Nutrition—everything from regulating blood sugar to repairing DNA. “Magnesium is found in all kinds of food, whether that be grains, fruits, vegetables, fish—just about anything that you can find in nature to eat, it's going to have some form of magnesium in it,” she says. “With magnesium, more is definitely not more,” says Dr.