Ammonia in our bodies

So far my knowledge body ammonia immediately converts to uric acid within body and excreted through urine.Free radicals in body can cause damage to hair.To protect our body from freeradicals we have to take a lot of antioxidant rich food. Vitamin A,VitaminC are good antioxidant.Fruit like carrot,orange,mango are good source of antioxidant.Even dark chcolates are good source of antioxidant.Spinach is excellent source of antioxidant. Other thing is heredity .If your family both maternal and paternal side has his history of early greying of hairs.Then there every possibity of greying hair in earlier age.