Sunlight exposure in inflammatory bowel disease outpatients: Predictive factors and correlation with serum vitaminD

Sunlight exposure is the main source of vitaminD. Our aim was to describe both sun exposure and sun protection behaviour in a series of patients with inflammatory bowel disease (IBD), and to study their potential association with vitaminD concentration.

A cross sectional, observational study. The clinical-demographic variables were obtained via clinical interviews and medical history review. The sunlight exposure assessment was carried out using the Sun Exposure Questionnaire and the concentration of 25-hydroxy vitaminD (25OHD) was measured by an electro-chemiluminescence immunoassay. Questionnaires were conducted on quality of life, physical activity, weekly vitaminD intake and sun protection behaviour.

149 patients were included. In 69% of patients, deficient or insufficient 25OHD values were recorded. 67% showed low sun exposure. A modest significant correlation was observed between the total score of the solar exposure questionnaire and the 25OHD concentration in the complete series (r=0.226, P=.006) and in the summer (r=0.274, P=.01). The sun protection behaviour questionnaire score did not influence the 25OHD concentration. In the multivariate analysis, only the presence of clinical activity was associated with low sun exposure (OR=3.23).

Sun exposure according to the questionnaire used was low, was associated with the presence of clinical activity and was weakly correlated with serum 25OHD concentration. More studies are needed to explore the use of individual questionnaires for sun exposure and its relationship with vitaminD in patients with IBD.