P447 Seasonal variations in Vitamin D concentrations in a single-centre inflammatory bowel disease series
P. Vernia*, G. Burrelli Scotti, M. T. Afferri, V. Vaiarello
Sapienza - University of Rome, Gastroenterologia A, Rome, Italy
Vitamin D (VitD) deficiency is frequent in inflammatory bowel disease (IBD), representing an important factor favouring osteoporosis. Because dietary VitD depends on adequate sunlight exposure to be converted in its active form, the aim of the present study has been evaluating the prevalence of VitD deficiency in different periods of the year.
We measured 25-OH VitD in 207 IBD patients (116 ulcerative colitis [UC] and 91 Crohn’s disease [CD]; 88 female and 117 male) and compared the prevalence of VitD deficit (< 2 0 ng/ml) in the period of maximum sunlight exposure in June–September (T1) with that in October–January (T2) and February–May (T3). Data were analysed using the Chi-square test.
VitD deficiency was present in 56.5% of IBD patients. It was significantly different between UC (44.9%) and CD (71.4%) (p < 0.0001) and it was similar in females and males. The probability of VitD deficiency was about the same in T1 (47.4% IBD) versus T2 (48.5% IBD) but significantly higher (p < 0.0013) in T3 (69% IBD). Older age (> 60 years), disease activity, and previous surgery were associated with increased prevalence of VitD deficiency (respectively, 68.2%, 77.3%, and 80%).
These data indicate that VitD deficit is highly prevalent in IBD throughout the year with peaks in winter-early spring, when it is observed in over two-thirds of patients. This is in keeping with the pivotal role of sunlight exposure, which has been demonstrated to be inadequate in IBD. Conversely gender does not seem to influence to a marked extent the prevalence of VitD deficiency, although the risk is maximum in CD females. These findings indicate that a large proportion of IBD patients presents with an important reversible risk factor for osteoporosis. VitD supplementations should be prescribed to all IBD patients. They are mandatory in winter and spring, and in all patients with other risk factors such as older age, previous surgery, high inflammatory activity, and corticosteroid therapy.