If your body doesn’t have enough vitamin B12, it can mess up the cells that give your hair its color, making your hair turn gray earlier than it should.

People who start going gray earlier than most tend to have less vitamin B12 in their blood and are more likely to be deficient in it than others their age.

People who go gray too early might have low levels of copper, iron, or vitamin B12—these nutrients might help keep hair its natural color.

If your hair is turning gray because you don’t have enough vitamin B12, fixing that deficiency might bring back your natural hair color—but this hardly ever happens, and it won’t work if something else is causing the graying.

People whose hair turns gray too early often have lower levels of iron, zinc, and copper in their bodies compared to people whose hair grays normally.