Seasonal variation of serum 25-hydroxyvitamin D levels in adult patients with inflammatory bowel disease

Abstract

SummaryPatients with inflammatory bowel disease (IBD) are at risk of osteoporosis. Vitamin D (vitD) deficiency is known as a risk factor of osteoporosis. We observed low vitD blood levels in adult IBD patients both at the end of summer and winter. Furthermore, effects of oral vitD supplementation in (generally low) daily dosages were poor.IntroductionPatients with IBD are at risk of osteoporosis. This study evaluates seasonal vitD status, determinants of vitD deficiency and effects of vitD supplementation in adult IBD patients.MethodsPatients were screened for vitD deficiency at the end of summer and winter using serum 25OHD3 (cut-off point, <50 nmol/L) combined with routine laboratory tests. A standardized questionnaire was used for demographic/lifestyle data i.e. IBD activity, health behaviour and vitD intake through diet and ultraviolet light.ResultsLate-summer, 39% of the included 316 patients were vitD deficient. Late-winter, 57% of the follow-up patients (n = 281) were deficient. Independent protective determinants of vitD deficiency were oral vitD supplementation (summer/winter: odds ratio [OR], 0.52 [95% confidence interval [CI], 0.29–0.94]/OR, 0.44 [95% CI, 0.26–0.75]), recent sun holiday (summer: OR, 0.42 [95% CI, 0.24–0.74]) and regular solarium visits (summer/winter: OR, 0.28 [95% CI, 0.13–0.63]/OR, 0.17 [0.06–0.50]). IBD activity (p = 0.031), red blood cell distribution width (RDW; p = 0.04) and erythrocyte sedimentation rate (p = 0.03) were associated with low vitD levels using univariate analyses of the extreme 25OHD quartiles. In a subgroup with vitD supplementation, still 30% (late-summer) and 44% (late-winter) were vitD deficient.ConclusionVitD deficiency is common in IBD patients, but prevalence might be comparable with the general population. Ultraviolet light is essential for adequate vitD levels. Effects of oral vitD supplementation in (generally low) daily dosages are poor. Determinants for low vitD levels were IBD activity and elevated inflammatory markers, suggesting that increased risk of osteoporosis in IBD might be more related to the inflammation than to vitD deficiency.

Increased Fracture Risk and Osteoporosis Not Associated With Vitamin D Levels in Malaysian Patients With Inflammatory Bowel Disease

“…The finding of low levels of vitamin D in IBD patients is common (9,22), and from our study, most of our IBD patients have inadequate levels of vitamin D and about a fifth were vitamin D deficient. As mentioned previously, Malaysia is a tropical country with high temperatures all year round without the seasonal variation in temperate climates (23). Despite the large amount of sunlight, however, an inadequate vitamin D level is generally a common phenomenon in Malaysia, even in the general population, particularly in urban areas (24,25).…”

The prevalence and risk factors for osteoporosis in patients with inflammatory bowel disease

“…There are several possible risk factors such as age (8,9), low body mass index (BMI) (8,10), malabsorption, vitamin D and calcium defi ciencies (11,12), bowel resection (9,13), hypogonadism, corticosteroid treatment (9,12,13,14,15), smoking (16), reduced physical activity and genetic factors (17).…”

“…Although there is evidence that long-term corticosteroid therapy reduces the BMD (9,12,13,14,15,22,23,24), some of stud-ies have suggested that BMD in IBD is unrelated to corticosteroid use (25,26,27,28,29). Considering the fact that newly diagnosed patients already have a reduced bone mineral density (BMD), there is a strong case for suggesting that demineralization in patients with IBD occurs primarily as a consequence of intestinal infl ammation.…”

Osteoporosis in Gastrointestinal Diseases

“…A major and common problem in patients with IBD is vitamin D deficiency. In a study by Bours et al, which included 316 patients, vitamin D deficiency was present in 39% of the patients during summer and 57% of the patients during winter [11]. Indications for DEXA testing according to the British Society of Gastroenterology may be: persistent active inflammatory bowel disease, > 10% weight loss, BMI of < 20 kg/m 2 , age > 70 years of age, treatment with GCs for a period of six months, patients < 65 years of age, in whom treatment with glucocorticoids is planned, if there are other known risk factors for osteoporosis.…”