Vitamin K status in patients with Crohn's disease and relationship to bone turnover.

Abstract

There is a high prevalence of osteopenia among patients with Crohn's disease (CD). There is some evidence that a deficiency of certain bone-active nutrients (including vitamins K and D) may have a partial role in this bone loss. To compare the intake and the status of vitamin K in CD patients, currently in remission, with age- and sex-matched controls, and furthermore to investigate the relationship between vitamin K status and bone turnover in these patients. CD patients (n = 44; mean age: 36.9 yr) and matched controls (n = 44) were recruited from the Cork University Hospital and Cork City area, respectively. Bloods were analyzed for the total and undercarboxylated (Glu)-osteocalcin and urine analyzed for cross-linked N-telopeptides of type I collagen (NTx). Vitamin K(1) intake was estimated by food frequency questionnaire. Vitamin K(1) intake in CD patients tended to be lower than that of controls (mean (SD), 117 (82) vs 148 (80) mug/d, respectively; p= 0.059). Glu and NTx concentrations in CD patients were higher than controls (mean (SD), 5.1 (3.1) vs 3.9 (2.1) ng/ml, respectively; p= 0.03 for Glu; and 49 (41) vs 25.8 (19.5) nM BCE/mM creatinine, respectively; p= 0.001 for NTx). In CD patients, Glu was significantly correlated with NTx (r= 0.488; p < 0.001), even after controlling for age, gender, vitamin D status, calcium intake, and corticosteroid use. Vitamin K status of CD patients was lower than that of the healthy controls. Furthermore, the rate of bone resorption in the CD was inversely correlated with vitamin K status, suggesting that it might be another etiological factor for CD-related osteopenia.