hello manoj it is interesting thought but there are no studies to suggest any relation between vitamin d and lichen planus.
It is also unlikely that many patients do not show any alteration in the course of their disease even with addition of vitamin d for lichen planus cases.
How can vitamin d link to lichen planus? For atopic dermatitis , there are studies support that vitamin d can increase lesional cathelicidin which might decrease S aureus colonization , results in AD improvement. We have finished clinical trial and on the process of submission.