I am 63 years old having controlled diabetes and hypertension through allopathic medicine for the last ten and eight years respectively. For the last 4-5 years I develop cracks under the sole of both feet and this aggravates during the change of season. Despite trying various types of pathies I am not cured of this problem. For the last few days I am taking Vitamin C tablets 500 mg daily. Please advise whether this will help in the treatment of cracks and if so how much mg to be taken daily. I am having a kidney stone of 7 mm. Please advise whether taking vitamin C can cause any enlargement of the stone?