Background/Aims: Individuals
with IBD (Crohn’s Disease (CD) and Ulcerative Colitis (UC)) may be at risk of
low vitamin D levels due to reduced absorption, use of sun-sensitising
medications, and increased requirements. Low
vitamin D levels in IBD have been associated with greater disease activity and
longer disease duration.
Methods: 186 men and women with IBD,
and 126 healthy controls, provided a blood spot sample to measure serum 25-hydroxyvitamin
D level. 198 of these participants completed a retrospective
questionnaire containing demographic data, sunlight exposure habits, vitamin D
supplementation, and disease activity. Difference between groups was tested
using ANOVA; frequency of vitamin D deficiency and adequacy was tested using
Chi-Square.
Results: No differences were observed between vitamin D level and disease, latitude,
or sun exposure hours. Lower vitamin D was significantly associated with recent
disease activity in patients with CD (66.0 ± 3.4; P=0.011),
but not UC, and in IBD after controlling for supplementation (57.8 ± 3.1;
P=0.018). Higher vitamin D was significantly
associated with supplement use (82.3 ± 3.9; P<0.01) and recent increased sun exposure (73.6 ± 2.5; P<0.01).
Conclusions: Vitamin D Supplementation
should be considered both during and in the 12 months following flare up of disease
activity in IBD.
Funding Sources: New Zealand
Federation for Graduate Women and Massey University Postgraduate Research Support.