Vitamin D and multiple sclerosis hospital admissions in Scotland

It is now acknowledged that seasonality is a main feature of the complex neurological disorder multiple sclerosis (MS). Having a spring birthday and being exposed to low levels of sunshine significantly increase the risk of MS later in life.1,2 Although global environment is dominated by seasonality, the observation that vitamin D status is inversely associated with risk of MS later in life and that vitamin D regulates the expression of a large number of MS associated genes, strongly indicate that ultra-violet (UV) light exposure and consequent effects on vitamin D production are involved in MS etiology.3,4 Intriguingly this essential hormone appears to also play an important role in influencing MS disease course. Studies have shown an inverse association between 25-hydroxyvitamin D (25-OH-D) levels and clinical MS severity and relapse rate.5 Furthermore, in a recent prospective investigation of a large cohort of MS patients, vitamin D status inversely correlated with relapses over the subsequent 6 months.6 Similar …