How to stop vitiligo spreads.

My daughter is 3.5 years old. Weight 15kg height 3ft 4inches. She is suffering from vitiligo from past 4months. Currently she has been taking Narrow Band UVB targeted phototherapy. We have seen significant improvement in her white patches. White Patches are located ok back, under arm, forearms, abdomen, knuckles, toes. My query here is how can we stop the spread of Vitiligo. Every couple of days we see a new white patch. Currently she is taking Calimax and Zincovit. Not eating any processed food. Everyday eats carrots, beetroot, dark chocolate, spinach soup, lentils, other vegetables, walnuts and pumpkin seed. We tried homepathy medicine to stop the spread for 3months but didn't work. Same with Ayurvedic. Now she is only on above mentioned multivitamin and phototherapy.