Why does hair turn gray prematurely? VnExpress Premature graying is not simply due to aging, but can also indicate underlying issues like vitamin B12 deficiency, thyroid disorders, or autoimmune diseases.
Why does hair turn gray at 20? VnExpress I'm 20 years old, but I have a lot of gray hair. Why is this happening, and how can I improve it? (Mai, Hung Yen)
