You are probably getting more magnesium than is reported. Magnesium is not a nutrient mandated to be on a food label. So many of the brand name food items do not list magnesium, even though it will be contained.
For an extensive listing, click this link. Click "nutrient lists" and select magnesium by amount: ndb.nal.usda.gov/
Also...do not take a magnesium supplement unless prescribed by your doctor.
SP Dietitian Becky