Genetics and stress. Genetics and stress are probably the two most common reasons.
Graying of hair is. Related to genetic predisposition. Age of initial graying is largely a matter of genetics. However stressors: nutritional deficiencies, chemotherapy, traumatic head injuries, low vitamin B levels, zinc deficiency, severe illness, surgery & marked emotional stress may impact earlier depigmentation in people who are already predisposed to gray hair. Aging is a significant factor. In general –