How Vitamins and Minerals Affect Your Teeth Dental cavities, or tooth decay, affect over 90% of the U.S. adult population. Gum disease, while less common, still affects an alarming 50% of adults over the age of 30. U.S. children are suffering too, with tooth decay affecting more than 40% of those between the ages of 2 and 19. Although gum disease is more common in adults (one in every two of them have ...