Inflamm Bowel Dis. 2020 May 9;izaa087.doi: 10.1093/ibd/izaa087. Online ahead of print.

Yuli Guzman-Prado ¹, Ondrej Samson ², Jonathan P Segal ^3 4, Jimmy K Limdi ⁵, Bu'Hussain Hayee ⁶

Author information

¹International Centre for Medical Research, Dorset, United Kingdom.

²Alltrista, Christchurch, Dorset, United Kingdom.

³Inflammatory Bowel Disease Department, St. Mark's Hospital, Harrow, United Kingdom.

⁴Department of Surgery and Cancer, Imperial College, London, United Kingdom.

⁵Inflammatory Bowel Diseases Section, The Pennine Acute Hospitals NHS Trust, Manchester Academic Health Sciences, University of Manchester, Manchester, United Kingdom.

⁶King's College Hospital NHS Foundation Trust, King's College London, United Kingdom.

Abstract

Background: Vitamin D deficiency has been implicated in the pathogenesis of inflammatory bowel disease. Emerging literature suggests that optimization of vitamin D levels may be associated with improvements in disease activity and quality of life. We conducted a meta-analysis exploring the effect of vitamin D on serum 25-hydroxyvitamin D (s-25[OH]D) levels, clinical improvement, and biomarkers.

Methods: MEDLINE, EMBASE, the Cochrane Library, and sources for grey literature were searched from inception until September 2019. The primary outcome was s-25(OH)D mean differences. Heterogeneity was assessed using the χ 2 test and the I2 statistic. Review Manager software v. 5.3 was used.

Results: Twelve randomized controlled trials (n = 611) and 4 observational studies (n = 359) were included in the meta-analysis. On average, in the randomized controlled trials, vitamin D supplementation increased s-25(OH)D levels by 15.50 ng/mL (95% confidence interval [CI], 11.08-19.92, P ≤ 0.00001, I2 = 90%) and in observational studies they increased by 18.39 ng/mL (95% CI, 8.91-27.88, P = 0.0001, I2 = 82%). Subgroup analyses between vitamin D and placebo groups revealed that vitamin D increased s-25(OH)D by 14.85 ng/mL (95% CI, 9.96-19.73, P ≤ 0.00001, I2 = 90%) and when high doses of vitamin D were compared with low doses, high doses increased s-25(OH)D by 18.27 ng/mL (95% CI, 5.44-31.10, P = 0.005, I2 = 90%). The Harvey Bradshaw Index improved by -1.47 points (95% CI, -2.47 to -0.47, P = 0.004, I2 = 0%) and the high-sensitivity C-reactive protein decreased by -1.58 mg/L (95% CI, -2.95 to -0.21, P = 0.02, I2 = 0%).

Conclusions: Vitamin D supplementation in patients with IBD and vitamin D deficiency is effective at correcting vitamin D levels and is associated with improvement in clinical and biochemical disease activity scores.