Magnesium is essential for a healthy body, and it comes from the foods we eat and supplements we take. It’s one of the seven key minerals that our bodies need in large amounts to function properly. We could have a magnesium deficiency without it. Taking magnesium supplements is safe, as long as you don’t go too far beyond the recommended dose for your age. The following are suggested doses. If you have a medical condition, it’s always best to check with your doctor to see if magnesium supplements are safe. The dosages for children are much lower than those for adults.