Effect of vitamin D and/or omega-3 fatty acid supplementation on stroke outcomes: A randomized trial

Among stroke patients, low serum 25-hydroxyvitamin D predicts poor outcomes. In mice, higher omega-3 (n-3) fatty acid intake diminishes brain damage after stroke. In this study, we tested whether vitamin D or n-3 fatty acids supplementation prior to stroke reduces the risk of functional limitations and physical disability after stroke.

We used data from VITAL (the VITamin D and OmegA-3 TriaL) which randomized middle-aged and older men and women without cardiovascular disease to vitamin D₃ (2000 IU/day) and/or marine n-3 fatty acids (1 g/day) and followed them for incident stroke events. Individuals experiencing a non-fatal stroke were mailed questionnaires assessing functional limitations (the physical performance scale adapted from Nagi) and physical disability (the modified Katz Activities of Daily Living and Rosow-Breslau Functional Health scales). We used logistic regression to analyze associations between randomized treatment and limitations on each scale.

A total of 290 individuals experienced their first stroke during the trial, of whom 197 stroke survivors completed the stroke outcomes questionnaire a median of 1.4 years after diagnosis. We observed no associations between randomized treatment to vitamin D and functional limitations (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.52, 1.97) or physical disability (Rosow-Breslau scale: OR 0.92, 95% CI 0.50, 1.67; Katz scale: OR 1.03, 95% CI 0.31, 3.42). Those randomized to n-3 fatty acids had a non-significantly lower risk of functional limitations (OR 0.55, 95% CI 0.28, 1.09) and physical disability (Rosow-Breslau scale: OR 0.56, 95% CI 0.31, 1.02; Katz sclae: OR 0.32, 95% CI 0.50, 1.67).

Vitamin D or omega-3 fatty acid supplementation prior to stroke did not result in significantly improved post-stroke outcomes.