There are many hypothesis to define the causation of vitiligo.  But the real fact about  vitiligo causes are not fully obvious.  If we take a microscopic view of the disease or vitiligo patches in a patient skin it is clear that these colorless patches have no melanocyte or melanin in them.

 Melanocytes: a special skin cells white produce skin color, the output of melanocytes are a substance called melanin. The presence of melanin is in a part of the skin is necessary for skin. And in vitiligo spot as its microscopic snapshot show there is no melanin in these spots.

 What would be the causes of vitiligo but it is clear first pigmentation cells in skin are destroyed and a deficiency of skin pigment (melanin) occurs. With the passage of time this deficiency slowly increase and after some period of time  there is complete loss of pigment in that part which shown as white spot of depigmentation.

 Scientist are in the search of the medicine are any substance which is useful of the production of melanin and which is helpful to enhance the activity of melanocytes cells. 

Hence  the  deep view of the vitiligo suggest that melanocytic activity is more prominent factor to be handle if you want to get rid from this skin disorder.