Vitamin D and long-term memory in multiple sclerosis.
OBJECTIVE
Memory disturbance is a frequent cognitive complaint by patients with multiple sclerosis (MS). Recent dementia research suggests a beneficial role for vitamin D in long-term memory functioning. While data suggest ameliorative effects of vitamin D for the physical impairments of MS, it is unknown whether vitamin D can benefit the cognitive sequelae. We examined the relationship between serum levels of vitamin D and performance on verbal and nonverbal tests of long-term memory in patients with MS.


METHODS
A sample of 35 adults with relapsing-remitting MS completed cognitive testing and a vitamin D serum (25[OH]D) assay. Memory assessment used clinically established neuropsychological tests with multiple testing formats to determine whether vitamin D level was associated with memory during conditions of varying retrieval demands. Intellectual functioning and mood were also assessed to control for potential confounds.


RESULTS
Vitamin D level was positively associated with performance on immediate and delayed recall trials of the Rey Complex Figure Test, effects that held after controlling for intelligence and disease duration. Vitamin D level was not associated with mood, intelligence, or verbal memory performance on the California Verbal Learning Test, Second Edition.


CONCLUSIONS
Higher vitamin D level was associated with better nonverbal long-term memory performance in MS, particularly in conditions when no aid was given to help retrieval. These results supplement the literature on the neuroprotective effects of vitamin D and suggest that vitamin D is a worthwhile adjunct treatment for MS.
*Program of Neuroscience, Bates College, Lewiston, ME †Central Maine Medical Center Neurology, Auburn, ME.
Nancy S
NS
Koven
Margaret H
MH
Cadden
Sangita
S
Murali
Mitchell K
MK
Ross
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008569:Memory Disorders / Q000097:blood* / Q000209:etiology*; D057567:Memory, Long-Term; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000097:blood* / Q000150:complications*; D009483:Neuropsychological Tests; D014807:Vitamin D / Q000097:blood*; D055815:Young Adult
D014807:Vitamin D