Have you considered that you might have a zinc deficiency?” Zinc. Zinc is an essential mineral that's vital to your health. In fact, a deficiency in zinc may impair skin health, digestion, immune function, reproductive health, and growth and development ( 6 ). It can also cause chapped lips, as well as dryness, irritation, and inflammation on the sides of your mouth”. If you do decide to take Zinc you also need to take copper.