Here are seven conditions magnesium may help treat or prevent. High Blood Sugar and DiabetesConsuming high amounts of magnesium is linked to a lower risk of diabetes, likely because magnesium can help metabolize glucose (sugar). Different types of magnesium are commonly used to treat constipation, including magnesium citrate, hydroxide, oxide, and sulfate salts. The daily upper limit for magnesium in dietary supplements and medications is 350 milligrams (mg), not including magnesium naturally found in food. Magnesium supplements may interact with medications like:Bisphosphonates : These drugs treat osteoporosis.