Phototherapy dosage is based on the skin’s response. The darker the skin, the longer the dosage required. Many people have expressed concern that nbUVB would be less effective for them, because they have particularly dark skin. A study that was released on 08/07/2009 by the Indian Journal of Dermatology, Venereology and Leprology (IJDVL) offers proof to the contrary.

Out of the 150 patients who were treated twice weekly for a year (every other day is considered the optimal regimen), 99 patients saw repigmentation of 25% or more. The remaining 51 patients did see repigmentation, but less than 25% of their affected areas. As with all other studies conducted to this date, nbUVB was found to be both safe and effective with good to excellent results, and virtually no negative side effects.

The article can be read here: Evaluation of narrow-band UVB phototherapy in 150 patients with vitiligo

Had the subjects been treated at the more medically therapeutic rate of once every two days, the results would likely have been even more positive. It is worth noting that vitiligo is a particularly stigmatizing condition amongst the Indian population. Even worse, there is a higher than average incidence of vitiligo throughout the country. It is often called "white leprosy" and those who have it are treated like ‘lepers’; often prevented from marrying.

Kumar YH, Rao GR, Gopal K, Shanti G, Rao KV. Evaluation of narrow-band UVB phototherapy in 150 patients with vitiligo. Indian J Dermatol Venereol Leprol [serial online] 2009 [cited 2009 Aug 7];75:162-6. Available from: http://www.ijdvl.com/text.asp?2009/75/2/162/48662