Does vitamin D deficiency increase risk of IBD in older adults?

Serum vitamin D level or deficiency status does not appear to have a significant contribution to the development of elderly-onset inflammatory bowel disease (IBD), ulcerative colitis (UC), or Crohn’s disease (CD), a recent study has shown.

A total of 357,656 participants (mean age 57.9 years) without IBD at enrolment from the UK Biobank were included in the analysis. The investigators collected baseline blood samples and measured serum 25-hydroxyvitamin D (25[H]D) levels. They classified participants as having vitamin D deficiency (<50 nmol/L), insufficiency (50‒75 nmol/L), or sufficiency (≥75 nmol/L) based on predefined cutoffs.

Multivariable Cox regression was used to determine the hazard ratio (HR) and 95 percent confidence intervals (CIs) of related associations.

Of the participants, 196,499 (54.9 percent) had vitamin D deficiency and 121,035 (33.8 percent) had vitamin D insufficiency. More than 1,600 elderly-onset IBD cases were recorded during a median follow-up of 13.3 years.

Vitamin D deficiency (HR, 0.91, 95 percent CI, 0.78‒1.07) or insufficiency (HR, 0.86, 95 percent CI, 0.73‒1.01) did not significantly correlate with elderly-onset IBD compared with sufficiency. Likewise, each 10-nmol/L increase in serum 25(OH)D showed no significant association with elderly-onset IBD (HR, 1.00, 95 percent 0.98‒1.03), UC (HR, 1.00, 95 percent CI, 0.97‒1.03), or CD (HR, 1.01, 95 percent CI, 0.97‒1.05).

The highest vs the lowest quartile of serum 25(OH)D also showed no significant correlations with IBD (HR, 1.03, 95 percent CI, 0.89‒1.19), UC (HR, 1.06, 95 percent CI, 0.90‒1.26), or CD (HR, 0.93, 95 percent CI, 0.73‒1.20).

“Further sensitivity and subgroup analyses demonstrated similar results,” the investigators said.