The prevailing belief is that you cannot prevent nor reverse gray hair. Seems your time for going gray is genetically determined. Nutritional supplements, vitamins nor any other product cannot stop your rate of greying, so don’t waste your money.
Your hair’s color is the result of melanin. Melanin also causes your skin to darken in the sun.
Melanin is produced by pigment cells that are located in each hair follicle. As you age, pigment cells start to die. Less melanin, more gray.
And that is why hair turns grey. Then ultimately white.
But sometimes premature gray hair can be caused by an underlying health problem, such as:
Some go gray prematurely as a consequence of inheriting early greying genes. You can thank your parents for that.
Don’t feel you’re doing something wrong if your Asian pal still has their dark hair color. That part of the world tends to gray later.