External causes include excessive use of hair sprays and gels, improper use of
hair-coloring products, cold weather and dry indoor heating, infrequent shampooing of the
hair or inadequate rinsing of the scalp and hair.
Sometimes an allergy to dairy products, nuts and chocolates may cause dandruff, in which case you should avoid them for about eight weeks to be able to access its effect. Eat a healthy diet. You can also take vit B6 and vit A and E which are good for hair and skin.