Premature graying of hair is a nightmare for most Dermatologist. The medication suggested are good enough in light of present knowledge though the efficacy is not guaranteed. . There are many reasons for premature graying as nutritional deficiencies or stress, environmental hazards,genetics and so on. A thorough evaluation will help identifying the cause of it. Though treatment options are limited and not very promising,still attempts could be made to prevent further graying of hairs. Existing ones may or may not regain normal colour. Hope it helps.
Next Steps
Screen yourself for nutritional deficiencies including
vitamin D,
Vitamin B12, Iron and zinc levels.