Puberty is generally not the reason for the greying of hairs.In Puberty greying of hair can be due to hereditary,  stress , lack of proper sleep or deficiency of vitamins A ,C and B12 as Vitamin A, C and B12 are needed to increase the melanin production in your hair. 

For Vitamin C- citrus fruits like oranges, grapes, pineapple, and melon to your diet. 

For Vitamin A and B12 -vegetables like carrots, beans. You can have vegetable juice or soup 

If you are non vegetarian then add chicken liver, fish, and eggs to your  diet.

Vitamin B12 deficiency is more common in  vegetarians as vegetarian food doesn’t have Vitamin B12.

Mix a tablespoon of Brahmi leaves paste and Amla powder to a tablespoon of lemon juice and apply this to the scalp for half an hour before bath once a week.

By following the above routine we can prevent further greying and also check with your sleep pattern.

Include amla once a day in powder or fresh juice in your diet .