TOPLINE:

A meta-analysis found that vitamin D supplementation was associated with increased serum vitamin D levels in patients with inflammatory bowel disease (IBD) but did not produce consistent improvements in disease activity or inflammatory markers.

METHODOLOGY:

• Emerging evidence has linked vitamin D deficiency to IBD and prompted trials testing whether supplementation could modify disease activity. However, most trials have been heterogeneous and inconclusive.
• Researchers conducted a systematic review and meta-analysis to test whether vitamin D supplementation altered disease activity and related parameters in adults with IBD.
• They searched major databases and trial registries for studies published from June 2000 to April 2025 from multiple countries that enrolled adults with Crohn’s disease, ulcerative colitis, or unclassified IBD in active disease or remission.
• Researchers assessed various parameters including serum 25-hydroxyvitamin D (25-OHD) levels and disease activity indices (Crohn’s Disease Activity Index scores > 150), and inflammatory biomarker levels.
• Researchers quantified heterogeneity (I²) and rated study bias using relevant tools.

TAKEAWAY:

• The final review included 14 studies — mostly randomized controlled trials with some observational cohort studies; most studies had 6-12 months of follow-up. Several studies carried a moderate-to-high risk for bias.
• Vitamin D supplementation was associated with significantly increased levels of serum 25-OHD (10 studies; pooled standardized mean difference, 1.41; P < .00001), although with substantial heterogeneity between studies (I² = 89%).
• Pooled analysis of four studies found no significant reduction in disease activity with vitamin D supplementation; the effect nearly disappeared when an outlier was removed.
• Vitamin D supplementation had no consistent effect on levels of the inflammatory markers C-reactive protein or TNF-alpha, although some individual studies reported reductions. Findings on relapse rates remained heterogeneous.

IN PRACTICE:

“The findings suggest that any potential effect of vitamin D on Crohn’s Disease Activity Index scores is modest, inconsistent, and sensitive to influential trials, and the current evidence does not support a robust clinically meaningful reduction in disease activity,” the authors wrote.

SOURCE:

This study was led by Muhanad Alzahrani, MBBS, of Jeddah First Cluster, Joint Program of Family Medicine in Jeddah, Saudi Arabia. It was published online in Gastroenterology & Endoscopy.

LIMITATIONS:

Results varied widely and showed very high heterogeneity. Most studies had short follow-up durations and focused on Crohn’s disease. A moderate-to-high risk for bias in several studies, along with inconsistent reporting, lowered confidence in the pooled findings.

DISCLOSURES:

This study did not receive funds from any agency. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.