Vitamin D, IBD, and Causality

The importance of vitamin D has been noted in this blog previously (Common to be “D-ficient” ).  Now a study implicates vitamin D as a risk factor for developing inflammatory bowel disease, especially for Crohn’s disease (Gastroenterology 2012: 142: 482-89).  It is known that vitamin D influences innate immunity.  As such, it may play a role in the susceptibility to Crohn’s disease (CD) and Ulcerative colitis (UC).

This prospective study included 72,719 women (age 40-73) enrolled in the Nurses’ Health Study.  Research subjects completed an assessment of diet and lifestyle along with 25-hydroxy vitamin D [25(OH)D] levels.  The 25(OH)D levels were predicted; this prediction was based on a validated model which included vitamin D intake, sun exposure, race, and body mass index (J Natl Cancer Inst 2006; 98: 451-9).  This model was validated against directly measured 25(OH)D levels.

During nearly 1.5 million person-years of followup, 122 incident cases of CD and 123 cases of UC occurred.  The adjusted hazard ratio (HR) for the highest quartile of 25(OH)D was 0.54 for CD and 0.65 for UC compared to the lowest quartile.  Compared with a level less than 20, the highest quartile HR was 0.38 for CD and 0.57 for UC.

In addition, the authors identified a significant inverse association between dietary supplemental vitamin D and UC; an insignificant reduction in CD risk was noted with dietary intake.  Although it is difficult to determine causality, these data convincingly show that ‘healthy’ levels of vitamin D are associated with a lower risk of IBD.

Advertisements

12 thoughts on “Vitamin D, IBD, and Causality

  1. Pingback: Quality improvement and better outcomes in Pediatric Inflammatory Bowel Disease | gutsandgrowth

  2. Pingback: Vitamin D deficiency and metabolism in pediatric Crohn’s disease | gutsandgrowth

  3. Pingback: Will Vitamin D Prevent Osteoporosis –Probably Not | gutsandgrowth

  4. Pingback: Explaining the Vitamin D Paradox | gutsandgrowth

  5. Pingback: Does Sun Exposure Lower the Risk of Crohn Disease? | gutsandgrowth

  6. Pingback: Another Reason for Inflammatory Bowel Disease Patients to Take Vitamin D | gutsandgrowth

  7. Pingback: Why Adding Vitamin D May Not Help IBD | gutsandgrowth

  8. Pingback: Single High-Dose Oral Vitamin D Therapy (Stoss) for Children with Inflammatory Bowel Disease | gutsandgrowth

  9. Pingback: Get Here If You Can: Improved Vitamin D Status | gutsandgrowth

  10. Pingback: Vitamin D and IBD, More Data | gutsandgrowth

  11. Pingback: Understanding Why Vitamin D Deficiency is Not So Common Afterall | gutsandgrowth

  12. Pingback: Vitamin D and Ulcerative Colitis Remission | gutsandgrowth

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s