At a weekly dose of 20,000 IU VD in PwMS (relapsing remitting MS-RRMs) and disease-modifying drugs (DMD), Holmoy et al. did not achieve an overall effect on sNFL levels, but in a subgroup of patients not receiving DMD, sNFL decreased more than 30% [19]. This evidence concerns the gene DMD and relapsing-remitting multiple sclerosis.