Hi, Thanks for posting in HCM. I have read your description and understand your concern. What problem you are suffering from premature greying of hairs is mostly heredity in nature and is not curable with medication. Hair greying is an eventual and irreversible process that occurs with age. Vitamin D deficiency is not known to be directly associated with causing grey hairs. You can include consumption of gooseberries, coconut oil, curry leaves and consumption of black tea in your diet regularly. You can take supplements containing Biotin and antioxidant agents like Vitamin E, Vitamin C and Selenium, which would help to keep your hair and skin healthy. It would not reverse the hairs back to black which has already turned grey, but could certainly help to prevent the rapid progress of greying of hairs. The only other option is to dye the grey hairs using colours which is convenient for you. Hope the information provided would be helpful. All the best.