One tablespoon of salt for about three cups of flour comes to almost 4.5%. That is higher than even sea water. The experts recommend about 1.5-2% salt. There is also salt in the cheeses. For example, mozzarella cheese can have about 180-200 mg sodium per ounce. So, for about 7 ounces on a pizza, you are getting about an another half to five-eights of a teaspoon of salt, or about another 0.60% salt. Most tomato products also have salt added. The amounts can vary from one tomato product to another, with some with over 300 mg per serving of about a half cup, in which case you will get another fraction of a teaspoon of salt. Overall, you are perhaps getting close to 6% salt in your pizzas.