Vitiligo is a tough disease that is not easy to treat. It causes idiopathic (unknown cause) destruction of skin pigment cells called melanocytes and creates areas of skin with little or no melanin that look much lighter compared to the rest of the skin. This can affect a person's quality of life (QOL), self esteem and in some can instigate depression, so having an option that may help ameliorate vitiligo can be useful.
Here is a link to images of vitiligo. As you can see, it would be much nicer to not have vitiligo.
On that note, this fairly recent study suggests that oral zinc supplementation may have an impact on vitiligo. The following study abstract shows that zinc serum levels are lower than in people without vitiligo and suggests that zinc supplementation may be useful. They also show a negative correlation between between serum zinc level and vitiligo. So the lower the zinc level, the worse the vitiligo will be and the higher the zinc level, the less vitiligo was expressed:
This 2018 study also shows that zinc serum level is significantly lower in vitiligo, but goes even further and shows that increased age and duration of disease activity also results in even lower levels of zinc :
There are some who feel that vitiligo has oxidative stress as a major component that results in melanocyte destruction and zinc, although not normally thought of as an antioxidant, has antioxidant qualities as well as antiinflammatory qualities which is important because oxidative stress can also create inflammation. With that in mind, zinc does have some antioxidative and anti-inflammatory qualities as outlined in this study link:
Zinc functions as an antioxidant by different mechanisms.&text=Several studies have shown that, decreases oxidative stress (32).
The following study suggests that zinc may be useful in the treatment of vitiligo: