Published: May 20, 2013 | Updated: May 20, 2013
By Nancy Walsh , Staff Writer, MedPage Today

Action Points

• This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
• Note that this small randomized, controlled trial demonstrated that Vitamin D supplementation was associated with improved grip strength and certain quality of life metrics among patients with Crohn’s disease in remission.
• Be aware that certain imbalances in baseline covariates would seem to favor the treatment group.

ORLANDO — Patients in remission with Crohn’s disease who took vitamin D supplements had clinically meaningful improvements in quality of life, a researcher reported here.

In a randomized, placebo-controlled study, patients receiving the supplements whose blood levels of 25-dihydroxyvitamin D were at or above 30 ng/mL had mean scores on the Inflammatory Bowel Disease Questionnaire of 187.3, compared with mean scores of 163.2 among those not taking the supplements and whose blood levels remained below that cutoff (P<0.0001), said Tara Raftery, MD, of the University of Dublin in Ireland.

“That 24-point increase in quality of life score exceeded the 20-point increase that is considered clinically meaningful to patients and physicians,” she toldMedPage Today at the annual Digestive Disease Week.

Patients with Crohn’s disease often report poor quality of life as well as fatigue and loss of muscle strength, even when the disease is in remission.

A growing body of evidence is suggesting that vitamin D may influence muscle strength, and Crohn’s patients often have suboptimal levels of the vitamin.

They may have problems with absorption of the vitamin in the small bowel if that part of the gastrointestinal tract is affected by the disease or if they have had surgery, Raftery explained during a poster session.

In addition, patients are often advised to avoid the sun, which can further deplete the levels.

“And we don’t have much sun in Ireland anyway,” she said.

To examine the effects of supplementation, she and her colleagues enrolled 27 patients whose disease was in remission (hemoglobin and hematocrit were within normal ranges) to receive 2,000 IU vitamin D per day or placebo.

Participants’ mean age was 37, and women predominated.

At baseline, patients in the treatment group had vitamin D levels of 26.6 ng/mL, while levels for those in the placebo group were 19.9 ng/mL, which was not a statistically significant difference.

Grip strength in the dominant hand as measured on a dynamometer was 80.2 lbs. in the treatment group and 66.7 lbs. in the placebo group, while in the nondominant hand the scores were 78.6 and 64.8 lbs, respectively.

Fatigue scores were 20.1 and 22.5, respectively, and there were no significant between-group differences on these baseline patient characteristics.

After 3 months of vitamin D supplementation, levels of 25-dihydroxyvitamin D had risen to 35.2 ng/mL in the treatment group but had fallen to 15.5 ng/mL in the placebo group (P=0.021).

After treatment, grip strength had increased significantly in the vitamin D group in both the dominant (P=0.0191) and nondominant (P=0.0209) hands.

Significantly less fatigue in the treatment group was seen at 3 months on the various domains of the Multidimensional Fatigue Inventory:

• General fatigue: 4.63 versus 9.61 (P=0.047)
• Physical fatigue: 4.60 versus 6.50 (P=0.029)
• Reduced activity: 3.50 versus 5.50 (P=0.036)
• Mental fatigue: 3.3 versus 5 (P=0.053)

Finally, bowel and social domains of the Inflammatory Bowel Disease Questionnaire showed significant improvement in those who achieved higher vitamin D levels versus those who did not: 60.5 versus 51.5 for bowel domain (P=0.015) and 59.4 versus 44.5 for social domain (P=0.05).

“These findings suggest that patients with Crohn’s disease may benefit from vitamin D supplementation in muscle strength, fatigue, and quality of life,” she said.

The treatment is generally safe, but should be used with caution in patients with chronic kidney disease or active tuberculosis, she noted.

This was a pilot study, which was a limitation. However, she and her colleagues are now conducting a larger trial, which includes 130 patients and will continue for 12 months.