The main reasons for having white hair at a young age include genetics, vitamin and mineral deficiencies (especially vitamin B12), stress, thyroid issues, autoimmune diseases, smoking, and lifestyle factors. White hair appears when hair follicles lose melanin, the pigment that gives hair its color. Genetics is the dominant factor, so if early white hair runs in your family, you are more likely to experience it. Stress can accelerate hair turning white by depleting pigment-producing cells. Deficiencies in key nutrients like vitamin B12, iron, and copper can also reduce melanin production. Thyroid disorders and autoimmune conditions can interrupt pigment production as well. Reversing early white hair is rarely possible except in cases linked to stress or nutritional deficiencies where addressing the root cause may help. Professional consultation is advised if white hair appears suddenly or is accompanied by other symptoms. Using gentle hair care products and addressing lifestyle factors can also support hair health. This information summarizes common underlying causes and potential approaches to managing early white hair.