White hair at a young age can be caused by various factors, including genetics, vitamin deficiencies, autoimmune diseases, and exposure to air pollution, UV rays, and harsh hair products. Here are some possible causes of white hair at a young age:

• Genetics: Premature graying of hair can be inherited from parents.
• Vitamin deficiencies: Deficiencies in vitamin B12, vitamin D, and folate can cause hair to turn white prematurely.
• Autoimmune diseases: Autoimmune diseases such as alopecia and vitiligo can attack hair and cause loss of pigment.
• Stress: Stress can affect hair and cause premature graying.
• Exposure to air pollution, UV rays, and harsh hair products: These factors can cause hair to become colorless and lead to premature graying.

It is important to note that while some of these causes can be prevented or treated, others, such as genetics or aging, cannot be reversed. If you are concerned about premature graying of hair, it is recommended to consult a doctor or dermatologist to determine the underlying cause and appropriate treatment options.