New research published in Alimentary Pharmacology and Therapeutics suggests that higher vitamin D levels may reduce the risk of contracting Clostridium difficile infection for those with inflammatory bowel disease.
Clostridium difficile is a naturally occurring species of bacteria found in the gut and usually does not cause any problems in healthy people. However, certain health conditions can interfere with the balance of “good” bacteria in the gut, leading to an unhealthy increase in Clostridium difficile. This is called Clostridium difficile infection (CDI), which can cause complications ranging from diarrhea to life threatening inflammation of the colon due to the toxins the bacteria produces.
Evidence is emerging that supports a role for vitamin D in inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis. Epidemiological studies have shown that IBD patients are at increased risk of CDI, although it’s not known why.
Researchers in the present study were interested in whether low vitamin D levels in IBD patients, who are often vitamin D deficient, may be a risk factor for developing CDI.
They analyzed the medical records of 3,188 patients with Crohn’s disease or ulcerative colitis at 2 hospitals servicing the Boston area, who had at least one vitamin D measure as part of their routine care. The researchers then looked to see who went on to develop CDI and who didn’t. They wanted to know if there were any differences in their vitamin D levels. They also wanted to know if vitamin D levels correlated at all with risk of death from CDI.
Here’s what the researchers found:
- 35 of the 3,188 patients developed CDI. The mean time between the date the vitamin D level was drawn and then development of CDI was 228 days.
- The average vitamin D levels were significantly lower in patients who developed CDI (20.4 ng/mL) compared to patients who did not (27.1 ng/mL) (P= .002).
- After further analysis, they found that each 1 ng/mL increase in serum vitamin D was associated with a 4% reduction in the risk of developing CDI (P= .046).
- Patients who developed CDI and died later had significantly lower serum vitamin D levels (12.8±8.1 ng/mL) compared to those who were alive at the end of the follow up period (24.3± 13.2ng/mL)(P= .01).
The researchers were optimistic about their findings:
“We demonstrate that higher vitamin D levels were associated with a reduced risk of CDI in patients with IBD. This suggests a potential role for vitamin D in the pathogenesis of CDI. As well, it raises interesting possibilities of whether vitamin D may have a role as adjunct therapy for CDI. Further studies in IBD and non-IBD cohorts are essential to replicate our findings, investigate the mechanisms of this association and its implications for patient care.”
Whilst this research shows a potential connection between higher vitamin D levels and the possibility of developing CDI in IBD patients, the lengthy interim between measured vitamin D and development of CDI, 228 days, significantly impacts the strength of this analysis. This is because many patients who were deficient at the time of analysis may have been supplemented as a result. Also, the study is observational in nature and not meant to establish a causal relationship between vitamin D and development of CDI.
Further research should help to clarify if higher vitamin D levels in IBD patients are likely to reduce the risk of CDI. Vitamin D supplementation trials are needed to determine if vitamin D can help prevent CDI. Also, it would be interesting to explore the role of vitamin D in the development of CDI in cohorts free of IBD, to better understand the mechanisms behind this relationship.
Ananthakrishnan AN et al. Higher plasma vitamin D is associated with reduced risk of Clostridium difficile infection in patients with inflammatory bowel disease. Alimentary Pharmacology and Therapeutics, 2014.