Table 1.
Summary of published human studies outcomes evaluating vitamin D3 and its modulation of microbiota in inflammatory bowel disease.
| Group | Type of IBD | Treatment/Condition | Duration of Study | Outcome | Ref. |
|---|---|---|---|---|---|
| Adults n = 25 |
UC active or in remission | Oral pills: Vitamin D3: 40,000 IU weekly |
8 weeks | ↑ 25(OH)D ↓ clinical disease activity ↓ fecal calprotectin ↓ inflammation in active UC Trend in reducing mucolytic species in fecal microbiota |
[80] |
| Adults n = 17 |
CD in clinical remission | Oral: Vitamin D3: Day 1—3: 20,000 IU Day 4—28 (alternated): 20,000 IU |
4 weeks | ↑ 25(OH)D ↑ week 1: Alistipes, Barnesiella, Roseburia, Anaerotruncus, Subdoligranulum ↑ week 2: Faecalibacterium, Veillonella, Blautia, Fusicatenibacter, Intestinibacter ↑ week 4: Lactobacillus, Megasphera ↓ reduced diversity |
[96] |
| Adults n = 87 |
CD and UC active or in remission |
Comparison between Seasonal 25-(OH)D circulating levels (supplemented or not) |
Summer/autumm (HE) vs. winter/spring (LE) |
25(OH)D levels were correlated with changes in microbiome ↓ 25(OH)D → balanced microbiome composition |
[97] |
CD = Crohn’s Disease; HE = high sunlight exposure; IU = international units; LE = low sunlight exposure; UC = ulcerative colitis.