Hair turns gray when there's a decrease in the number of stem cells in hair follicles. While generally a genetic trait, gray hair in young people usually happens because there's a lack of nutrition in their diets, for example a vitamin B-12 deficiency is commonly cited as a cause for premature grays. However, you can help keep your hair from turning gray (or at least slow it down) by taking these supplements.
A daily dose of 300 mg of vitamin B5, also called pantothenic acid, can help prevent those dreaded grays. Food sources of B5 can help too, so make sure to incorporate egg yolks, whole grains, carrots and brewer's yeast into your diet.
Keep up our melanin production and restore your hair color by taking 4 mg daily of vitamin B6. You can find B6 in egg yolks, whole grain cereals, organ meats, brewer's yeast and vegetables.
B-12 supplements can help prevent premature gray hair too. Food sources include fish, meat, eggs, milk and spirulina.
You can take 300 mcg of biotin, also called vitamin H, daily to prevent your hair from graying (as well as keep it long and strong). Egg yolks, brown rice, whole grains, liver, milk and brewer's yeast are great food sources. Biotin strengthens the hair and works to prevent grays by helping to produce keratin.