Initial experience with vitamin D3 supplementation on cognitive function in NPSLE patients in Bangladesh

<b>Background:</b> Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease often affecting the central nervous system, resulting in neuropsychiatric SLE (NPSLE). Cognitive dysfunction, a common manifestation, significantly impacts quality of life. Vitamin D3, recognized for its neuroprotective and cognitive-enhancing properties, is a potential therapeutic option for NPSLE. <b>Objectives:</b> This randomized controlled trial (RCT) evaluates the effects of vitamin D3 supplementation on cognitive function in NPSLE patients. <b>Methods:</b> NPSLE patients (<i>N</i> = 72) of standard SLE care were allocated into an intervention group (<i>n</i> = 34) receiving vitamin D3 (40,000 IU) supplementation/week for 6 weeks, then 2000 IU/day for 3 months, and a control group (<i>n</i> = 38) without vitamin D3. Serum vitamin D3 concentration, mini-mental state examination (MMSE) scores, and brain hypo-perfusion images by single-photon emission computed tomography (SPECT) were obtained at baseline and after 6 months of follow-up. <b>Results:</b> Baseline characteristics (age, gender, BMI, waist-to-hip-ratio) were independent between groups. After the intervention, concentration of vitamin D3 (ng/mL) rose from 16.2 ± 4.9 to 28.3 ± 5.3 within the "intervention group" (<i>P</i> ≤ 0.001). Similarly, the mean differences of MMSE scores were significantly higher in Cases than Controls (2.2 vs. 0.3). Analysis of covariance (ANCOVA) revealed large effect sizes for vitamin D concentration (η²_p = 0.714) and medium effect sizes (η²_p = 0.460) for MMSE scores. Furthermore, an insignificant (<i>P</i> > 0.05) shift (moderate to mild) of brain hypo-perfusion level was observed over time. <b>Conclusion:</b> Vitamin D3 supplementation effectively increased serum vitamin D concentration by supporting its role as an adjunctive therapy in NPSLE patients, leading to improvements in cognitive function and brain perfusion levels.