['This study was conducted to determine 25-hydroxyvitamin D [25(OH) D] levels in serum, and to investigate their associations with stroke recurrence events in a 3-month follow-up study in Chinese patients with first-ever ischemic stroke.', 'From February 2014 to September 2015, consecutive first-ever ischemic stroke patients admitted to the Department of Emergency of our hospital were identified. Serum 25(OH) D levels were measured at admission. We followed the participants for a median of 3 months (range, 2.5-3.5 months) using a standard questionnaire. We used logistic regression models to assess the relationship between 25(OH) levels and risk of recurrent stroke. In this study, 349 ischemic stroke patients were included and completed follow-up. Thirty-seven patients (10.6%) had a stroke recurrence. Serum 25(OH) D levels in patients with recurrent stroke were significantly lower as compared with those in patients without recurrent stroke [9.9 (IQR, 7.9-14.8) ng/mL vs. 17.9 (IQR, 13.4-23.4) ng/mL; P\xa0<\xa00.001). After adjusting for traditional risk factors, serum 25(OH) D levels were negatively associated with the stroke recurrence (OR, 0.897; 95% CI, 0.848-0.950; P\xa0<\xa00.001). Compared with the first quartile of serum 25(OH) D levels, the second quartile OR for recurrent stroke was 0.466 (95% CI, 0.308-707; P\xa0=\xa00.006). For the third and fourth quartiles, it was 0.248 (95% CI, 0.100-0.618; P\xa0=\xa00.001) and 0.173 (95% CI, 0.062-0.482; P\xa0<\xa00.001), respectively.'] Does serum 25-hydroxyvitamin D predict early recurrent stroke in ischemic stroke patients?