Vitiligo is an acquired depigmenting disorder of uncertain etiology. Anecdotal reports imply that the disease responds to topical vitamin D analogs, suggesting that vitamin D may be involved in its pathogenesis. To investigate the relationship between vitamin D and vitiligo, investigators in China looked at polymorphisms (different versions of the gene) in vitamin D receptor genes in 749 vitiligo patients and 763 control subjects.
Polymorphisms in the BsmI, ApaI, and TaqI alleles (i.e. different versions of these genes) were significantly less frequent in vitiligo patients than in controls. A fourth allele (A 4th gene version), FokI (don’t ask !), was not associated with predisposition to vitiligo. In addition, serum 25(OH) vitamin D levels were measured in 171 vitiligo patients and 150 controls. There was a dose–response relationship between higher 25(OH) vitamin D levels and protection from vitiligo.
Comment: One of dermatologists’ great needs is a reliable treatment for vitiligo. Study results on the role of vitamin D analogs in vitiligo have conflicted. These results indicate that the variability may result from genetic polymorphisms in the vitamin D receptor, which would allow some patients, but not others, to respond to vitamin D analogs. Future studies evaluating the efficacy of vitamin D analogs are warranted, but with consideration of these polymorphisms in the efficacy analysis. The findings may also explain why phototherapy, which is known to increase vitamin D levels in the skin, is effective in some, but not all, vitiligo patients. The results also suggest that it may be possible to reduce the incidence or progression of vitiligo by ensuring that at-risk patients do not become vitamin D deficient.
— Craig A. Elmets, MD, Published in Journal Watch Dermatology October 5, 2012
ENGLISH VERSION of the Above :
Vitiligo, the so-called Michael Jackson disease, is a distressing skin problem for a lot of patients. Some treatments of vitiligo, which also raise the vitamin D level in those treated, seem to work in some patients but not the others. Why ? It is possible that the vitamin-D raising therapies only work in a sub-group of vitiligo patients with a particular genetic make-up.
In the near future, when genetic studies become dirt cheap and fast, patient with vitiligo may get a swab in the mouth, pay a few bucks, wait for 2 days, get a report and say, “Hey Dr., these vitamin D therapies may work on my white skin spots, let’s give it a go.” And we’ll all live happily ever after…
Dr Ken Ho