any dr ok advice baby is 8th month taking only vit d3 found 3 to grey hairs y is it any vit def

A. hi it is caused by many reasons like genetics , excess usage of cosmetic , nutritional deficiencies etc so , if a child is not having other symptoms then it could be genetical . please give head massage with warm coconut oil everyday use mild shampoo like Babyhug shampoo which is free from harmful chemicals and clinically approved