Magnesium blood test

Key facts Magnesium blood tests are used to find out if your magnesium levels are normal. There are many reasons why you might need a magnesium blood test. Your doctor will explain your test results. What is magnesium? Magnesium is a mineral. Your body needs some magnesium for healthy muscles, nerves, bones and blood sugar levels. It is essential for many processes in your body, such as: producing energy from food maintaining your blood pressure helping your cells absorb potassium and calcium Most of the magnesium in your body comes from the food you eat. Foods high in magnesium include: green vegetables, legumes and beans nuts and seeds