What is the cause of your numbness in your feet? Poor circulation, diabetes, neurological disorder and probably a host of other medical ailments...
My husband also has numbness only in his toes due to poor circulation and he is a border-line diabetic. Once it's there, it's there. Impossible to heal BUT you can try to prevent it from getting worse. Try Alpha Lipoic Acid - 600 mg. daily or you can go as high as 1200 mg. daily.
But I would suggest your FIRST step is to see a neurologist for a thorough evaluation of your medical status/condition. There could be something you are not even aware of causing it or even an answer to it. Alpha Lipoic Acid was the only recommendation my husband's neurologist made to hopefully not make it worse. Good luck!