Yes. Magnesium is important. It is involved in over 300 chemical reactions including muscle, nerve, immune system, heart and bone functions. Adult men need up to 420 mg/day, with younger men, women and children needing less. There is plenty in foods like cereal, nuts, beans, and spinach, so a supplement may not be needed. More info: http://ods. Od.Nih. Gov/factsheets/magnesium-healthprofessional/.