In the kidney, salt and calcium are co-transported, meaning they are pumped out into the urine together, therefore, when you have a diet high in sodium and your kidney is pumping that sodium (salt) out, calcium is pushed out as well as an innocent bystander. The first piece of advice
I would give you is to cut down the salt in your diet
. remember that it can be hidden in prepared foods, so you have to ask and pay attention to sodium content. Your goal is 2000mg of sodium per day or less.