Citrus Fruits. Citrus fruits, particularly lemons, which contain vitamins A, B and C as well as calcium, phosphorus, potassium and fiber, are blood-cleansing foods.
Another great way to reduce oil production in the scalp is by breaking up the grease before it gets into your body. To do this, every morning drink 1 pint of warm water with the juice of 1 lemon squeezed in. Add to this 1 pinch of himalayan salt, and half a teaspoon of cayenne pepper.
1 Baking soda is also great for treating a dry scalp, dandruff, fungus on the scalp and makes a great clarifying shampoo. Just mix 1 tablespoon with enough water to make a paste and then use for your normal shampoo.  Forget a dermatologist, go to a trichologist. They specialize in hair and scalp care.