Anecdotal evidence: my extremely effective anti psoriasis spray contains a vitamin D derivative (calcipotriene) and since I started shaving my head (more uv on

Anecdotal evidence: my extremely effective anti psoriasis spray contains a vitamin D derivative (calcipotriene) and since I started shaving my head (more uv on the skin so more vitamin D is produced where needed) I had no need for that expensive spray.