- 
          
          J. Clin. Endocrinol. Metab. · Sep 2018 Observational StudyVitamin D and Inflammatory Bowel Disease: Mendelian Randomization Analyses in the Copenhagen Studies and UK Biobank.- Josephine Lund-Nielsen, Signe Vedel-Krogh, Camilla Jannie Kobylecki, Jørn Brynskov, Shoaib Afzal, and Børge G Nordestgaard.
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Copenhagen, Herlev, Denmark.
- J. Clin. Endocrinol. Metab. 2018 Sep 1; 103 (9): 3267-3277.
 ContextVitamin D may be a modifiable risk factor for inflammatory bowel disease (IBD).ObjectivesWe tested the hypothesis that plasma 25-hydroxyvitamin D levels are causally associated with risk of Crohn disease (CD) and ulcerative colitis (UC).Design, Setting, Patients, And InterventionsWe used a Mendelian randomization design to study 120,013 individuals from the Copenhagen City Heart Study, the Copenhagen General Population Study, and a Copenhagen-based cohort of patients with IBD. Of these, 35,558 individuals had plasma 25-hydroxyvitamin D measurements available, and 115,110 were genotyped for rs7944926 and rs11234027 in DHCR7 and rs10741657 and rs12794714 in CYP2R1, all variants associated with plasma 25-hydroxyvitamin D levels. We identified 653 cases of CD and 1265 cases of UC, of which 58 and 113, respectively, had 25-hydroxyvitamin D measurements available. We also included genetic data from 408,455 individuals from the UK Biobank, including 1707 CD cases and 3147 UC cases.Main Outcome MeasureHazard ratios for higher plasma 25-hydroxyvitamin D levels.ResultsThe multivariable-adjusted hazard ratios for 10 nmol/L higher 25-hydroxyvitamin D level were 1.04 (95% CI: 0.93 to 1.16) for CD and 1.13 (95% CI: 1.06 to 1.21) for UC. A combined 25-hydroxyvitamin D allele score was associated with a 1.4-nmol/L increase in plasma 25-hydroxyvitamin D level and hazard ratios of 0.98 (95% CI: 0.94 to 1.03) for CD and 1.01 (95% CI: 0.97 to 1.05) for UC. Combining genetic data from the Copenhagen studies and the UK Biobank, genetically determined vitamin D did not appear to influence the risk of CD or UC.ConclusionsOur results do not support a major role for vitamin D deficiency in the development of IBD. Notes
 Knowledge, pearl, summary or comment to share?You can also include formatting, links, images and footnotes in your notes- Simple formatting can be added to notes, such as *italics*,_underline_or**bold**.
- Superscript can be denoted by <sup>text</sup>and subscript<sub>text</sub>.
- Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens-or asterisks*.
- Links can be included with: [my link to pubmed](http://pubmed.com)
- Images can be included with: 
- For footnotes use [^1](This is a footnote.)inline.
- Or use an inline reference [^1]to refer to a longer footnote elseweher in the document[^1]: This is a long footnote..