Measuring Vitamin D Status in Chronic Inflammatory Disorders: How does Chronic Inflammation Affect the Reliability of Vitamin D Metabolites in Patients with IBD?

Abstract

Evidence gained from recent studies has generated increasing interest in the role of vitamin D in extraskeletal functions such as inflammation and immunoregulation. Although vitamin D deficiency has been implicated in the pathophysiology of inflammatory diseases including inflammatory bowel disease (IBD), evidence as to whether vitamin D supplementation may cure or prevent chronic disease is inconsistent. Since 25OH-vitamin D (25OHD) has been suggested to be an acute-phase protein, its utility as a vitamin D status marker is therefore questionable. In this study, possible interactions of vitamin D and inflammation were studied in 188 patients with IBD, with high-sensitivity C-reactive protein (hsCRP) levels ≥ 5 mg/dL and/or fecal calprotectin ≥ 250 µg/g defined as biochemical evidence of inflammatory activity. Levels of 25OHD and vitamin D-binding protein (VDBP) were determined by ELISA, and 1,25-dihydroxyvitamin D (1,25OHD) and dihydroxycholecalciferol (24,25OHD) by LC-MS/MS. Free and bioavailable vitamin D levels were calculated with the validated formula of Bikle. Serum 1,25OH2D and vitamin D binding protein (VDBP) levels were shown to differ between the inflammatory and noninflammatory groups: patients with inflammatory disease activity had significantly higher serum concentrations of 1,25OH2D (35.0 (16.4–67.3) vs. 18.5 (1.2–51.0) pg/mL, p < 0.001) and VDBP (351.2 (252.2–530.6) vs. 330.8 (183.5–560.3) mg/dL, p < 0.05) than patients without active inflammation. Serum 24,25OH2D levels were negatively correlated with erythrocyte sedimentation rate (ESR) (−0.155, p = 0.049) while concentrations of serum 1,25OH2D correlated positively with hsCRP (0.157, p = 0.036). Correlations with serum VDBP levels were found for ESR (0.150, p = 0.049), transferrin (0.160, p = 0.037) and hsCRP (0.261, p < 0.001). Levels of serum free and bioavailable 25OHD showed a negative correlation with ESR (−0.165, p = 0.031, −0.205, p < 0.001, respectively) and hsCRP (−0.164, p = 0.032, −0.208, p < 0.001 respectively), and a moderate negative correlation with fecal calprotectin (−0.377, p = 0.028, −0.409, p < 0.016, respectively). Serum total 25OHD concentration was the only vitamin D parameter found to have no specific correlation with any of the inflammatory markers. According to these results, the traditional parameter, total 25OHD, still appears to be the best marker of vitamin D status in patients with inflammatory bowel disease regardless of the presence of inflammation.

Metabolomics as a Promising Resource Identifying Potential Biomarkers for Inflammatory Bowel Disease

“…In this line, Aksan and colleagues have recently reported a study in which they analysed the serum levels of 25OHD, vitamin-D-binding protein (VDBP), 1,25-dihydroxyvitamin D (1,25OHD) and dihydroxycholecalciferol (24,25OHD) in a cohort of IBD patients and demonstrated that serum total 25OHD was the only vitamin D metabolite without a correlation with the levels of inflammatory parameters. Hence, in this study, authors suggest that total 25OHD seems to be the best marker of vitamin D concentration in IBD patients regardless of the inflammatory status [108]. However, there are still several questions that still need an answer: Is the supplementation of vitamin D beneficial for IBD patients?…”

Nutrients in the Prevention of Osteoporosis in Patients with Inflammatory Bowel Diseases

“…The deficiency was observed in 52% of children with IBD [ 53 ]. A sufficient vitamin D level was found more often in patients with a non-inflammatory disease activity; however, the serum concentration level was not correlated with any inflammatory markers [ 54 ]. In terms of IBD patients, a vitamin D dose of 1820 IU was sufficient to maintain the normal 25(OH)D serum level [ 55 ].…”

Potential of Antithrombin III as a Biomarker of Antidepressive Effect in Major Depressive Disorder

“…Of the four proteins, no notable differences were found in the sham group between baseline and day 5, suggesting the possible relevance of these proteins to the therapeutic process of occipital rTMS. Based on mounting evidence, inflammatory response is considered the common pathway of these four candidate biomarkers (55)(56)(57)(58), and is speculated to be a promising target of multiple non-convulsive neurostimulation interventions, including rTMS (59,60), which might partly account for the differences in protein alterations between rTMS and sham treatment.…”