Low and behold, tomatoes are huge lovers of lime so, when you are planting your tomatoes put some dolopril lime on top of the soil around the plant to provide the calcium. I personally add eggshells to my tomatoes but, lime works well to.
Incidentally if tomatoes are lacking in calcium (found in lime and eggshells) they can develop a blossom end rot on the fruit. So, give your plants a good dose of calcium. There is also a calcium spray out there that you can spray your fruit and plants with.