No. 1 pharmacist recommended (US News & World Report and Pharmacy Times. 2019-2020). Most concentrated for of magnesium supplement. Pharmaceutical grade. Coated, easy to swallow. Most concentrated form of magnesium. The Importance of Normal Magnesium Intake: Helps maintain normal muscle and nerve function. Helps maintain healthy heart rhythms. Helps in the absorption of calcium and potassium,. Helps support glucose metabolism. Pharmaceutical Grade quality. Mag-Ox 400 has been manufactured to rigorous quality standards for over 50 years. Reason Why Magnesium is Critical: Dietary Intake Up to 75% of Americans don't get enough magnesium in their diets. Prescription Drugs - Diuretics, proton pump inhibitors, cisplatin, and cyclosporin may deplete magnesium. Optimal Health - Magnesium is an essential mineral needed by every cell in the body. Involved in more than 300 chemical reactions, it's critical in helping to convert carbohydrates, protein and fat into energy - helping support the formation and release of energy from cells.