Low Vitamin D Linked to Increased Risk of Relapse in Ulcerative Colitis

Lower levels of vitamin D associated with an increased risk of disease relapses in patients with ulcerative colitis (UC), according to a study published inClinical Gastroenterology and Hepatology.

Research has shown an association between low levels of vitamin D and active disease in patients with UC, but whether it increased clinical relapse was unknown.

“Prior studies in patients with Crohn’s disease and ulcerative colitis had linked low vitamin D levels to disease flare-ups,” said senior author Alan Moss, MD. “However, it has been unclear if the flare-up was lowering vitamin D levels, or if low vitamin D levels were causing the flare-up. We thought that if we looked at vitamin D levels when the disease was inactive and then followed patients moving forward, the impact of baseline vitamin D levels on future events may be clearer.”

The investigators obtained vitamin D serum levels from a physician-blinded prospective study of 70 patients with UC, who were in clinical remission and were followed-up after a surveillance colonoscopy.

Vitamin D levels in blood samples as well as levels of inflammation were measured through blood tests and biopsies. The investigators then followed the patients for 12 months and compared the data from patients who remained well with those who experienced relapses.

The results of the study showed that the mean baseline vitamin D level was lower in patients who later relapsed compared with those who did not.

“Patients who had higher vitamin D levels when their disease was in remission were less likely to experience a relapse in the future,” said first author John Gubatan, MD. “This suggests that higher vitamin D levels may play some role in preventing the UC relapse.”

The authors noted that the threshold level of blood vitamin D that was protective was greater than 35 ng/ml. This figure is within the range for a healthy individual as recommended by the National Institutes of Health.

Currently, the investigators are examining the link between vitamin D and the protein cathelicidin in the cells that line the colon, which may have beneficial effects on microbial composition. Building upon this work, the investigators hope to uncover how vitamin D may protect cells in the colon and the microbial composition of the bacteria, fungi, protozoa, and viruses that live in the body.