Going gray, by itself, does not mean you have a medical problem, except in rare cases. Contrary to popular belief, stress has not been shown to cause gray hair. Scientists don’t know exactly why some people go gray early, but genes play a large role. Also, a vitamin B-12 deficiency or problems with your pituitary or thyroid gland can cause premature graying that’s reversible if the problem is corrected. Some research has suggested a connection between premature graying and lower bone density later in life. "Your level of bone density is related to activity level, your weight, your height, your ethnicity. It’s not related to your hair or the things controlling the color of your hair," ....consult dermatologist they will guide you