Pilot Study Suggests Link Between Low Vitamin D and Executive Function in MS

Background: Vitamin D has become increasingly relevant within the MS literature in recent years as low levels of vitamin D have been shown to predict MS relapses and correlate with overall disease worsening. Cognitive impairment is a common and debilitating MS symptom as well as an important indicator of general disease state. It is not known whether a relationship exists between vitamin D deficiency and MS cognitive impairment.

Objectives: To test pilot data for a possible relationship between MS cognitive impairment and Vitamin D deficiency in advance of a larger prospective study.

Methods: Analysis was performed on a subset (n=22) of MS patients from a large database which is part of an ongoing study of MS cognitive function at the Comprehensive MS Center at Holy Name Medical Center in Teaneck, NJ. All patients were given a battery of neurocognitive tests, (MACFIMS battery) and data was analyzed for those patients with available vitamin D levels measured within 6-months of cognitive testing. Cognitive impairment was measured both as an overall score and according to discrete functional domains.  Spearman Rank Order Correlations (rho) were run to measure correlation.

Results: There were no significant correlations observed between vitamin D deficiency and general cognitive impairment or discrete domains.  The strongest correlation observed was that of Vitamin D and executive function (rho=.369) which trended toward significance (p=.11) even in this small sample.

Conclusions: The sample analyzed was too small to determine any relationship between vitamin D deficiency and MS cognitive impairment; however, data suggest that when conducting a more complete study attention should be given to discrete domains of cognitive function and particularly to executive functions.