Seasonal variability of vitamin D status in patients with inflammatory bowel disease - A retrospective cohort study

• Published in: PloS one 2019-05, Vol.14 (5), p.e0217238-e0217238
• Main Authors: Janssen, Christine Elisabeth, Globig, Anna Maria, Busse Grawitz, Andrea, Bettinger, Dominik, Hasselblatt, Peter
• Format: Article
• Language: English
• Subjects: 25-Hydroxyvitamin D; Adolescent; Adult; Aged; Aged, 80 and over; Anemia; Biology and life sciences; Cohort analysis; Cohort Studies; Colitis; Colitis, Ulcerative - blood; Colitis, Ulcerative - complications; Complications; Control; Crohn Disease - blood; Crohn Disease - complications; Crohn's disease; Crohns disease; Diarrhea; Dietary Supplements; Drug dosages; Earth Sciences; Ethics; Female; Gastrointestinal diseases; Germany - epidemiology; Health risks; Hospitals; Humans; Inflammatory bowel disease; Inflammatory bowel diseases; Inflammatory Bowel Diseases - blood; Inflammatory Bowel Diseases - complications; Intestine; Laboratories; Male; Medical research; Medicine; Medicine and health sciences; Metabolism; Microbiota; Middle Aged; Osteoporosis; Patients; Physical sciences; Prevalence; Prevention; Regression analysis; Research and Analysis Methods; Retrospective Studies; Risk analysis; Risk Factors; Seasonal variability; Seasonal variations; Seasons; Smoking; Studies; Supplements; Surgery; Ulcerative colitis; Variability; Vitamin D; Vitamin D - administration & dosage; Vitamin D - analogs & derivatives; Vitamin D - blood; Vitamin D deficiency; Vitamin D Deficiency - blood; Vitamin D Deficiency - complications; Vitamin D Deficiency - epidemiology; Vitamin deficiency; Vitamins; Winter; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0217238

Vitamin D deficiency predicts unfavorable disease outcomes in inflammatory bowel disease. Endogenous vitamin D synthesis is affected by seasonal factors including sunlight exposure, raising the question whether seasonality determines the risk of vitamin D deficiency and may mask other clinical risk factors. Univariable and multiple regression analyses were performed in a retrospective cohort of 384 patients to determine risk factors for vitamin D deficiency. Since the observed 25-hydroxyvitamin D [25(OH)D] concentrations followed a sinusoidal pattern over the year, all 25(OH)D concentrations were normalized for the predicted variability of the respective day of analysis based on a sinusoidal regression analysis of 25(OH)D test results obtained in more than 86,000 control serum samples. Vitamin D deficiency was highly prevalent in patients with Crohn's disease or ulcerative colitis (63% and 55%, respectively) and associated with winter/spring seasons. After normalization of 25(OH)D concentrations for the day of analysis, vitamin D deficiency was associated with histories of complications related to inflammatory bowel disease, surgery, smoking and ongoing diarrhea while initial disease manifestation during adulthood, ongoing vitamin D supplementation and diagnosis of ulcerative colitis vs. Crohn's disease appeared to be protective. Multiple regression analyses revealed that vitamin D deficiency was associated with disease activity in Crohn's disease and anemia in ulcerative colitis patients. Only few deficient patients achieved sufficient 25(OH)D concentrations over time. However, increasing 25(OH)D concentrations correlated with improved Crohn's disease activity. Vitamin D deficiency was highly prevalent in patients with Crohn's disease and ulcerative colitis and dependent on the season of the year. Following normalization for seasonality by sinusoidal regression analysis, vitamin D deficiency was found to be associated with parameters of complicated disease course while increasing 25(OH)D concentrations over time correlated with reduced activity of Crohn's disease.