CELTIC SALT AND SPINACH COMPARED NUTRIENT CELTIC SALT (½ T.) SPINACH (1 C.) Calcium, mg 5.3 245 Potassium, mg 3.8 839 Magnesium, mg 13.5 157 Phosphorus, mg 0.002 102 Iron, mg 0.08 6.4 Zinc, mg 0.0001 1.4 Copper, mg 0.0001 0.3 Fluoride, mcg 0.01 68 Manganese, mg 0.02 1.7 Selenium, mcg 0.0001 2.7