In recent years, theories about the anti-inflammatory properties of vitamin D in demyelinating disease have been well substantiated by human studies examining relapse reduction, MRI lesion activity and risk of MS conversion. However, the evidence that vitamin D may protect against neurodegeneration has not been established as of yet, and comes with the challenges of a manageable target over a manageable time period. Such challenges might be overcome by the anterior visual pathway (AVP) model of the central nervous system, which allows the non-invasive study (e.g. imaging, electrophysiology and clinical) of form and function within a much shorter time frame than pure clinical activity. This review outlines the state of current knowledge about vitamin D in demyelinating disease, and highlights the potential utility of using the AVP to study its neuroprotective effects.