Inadequate sunlight exposure in patients with inﬂammatory
Piero VERNIA, Giorgia BURRELLI SCOTTI , Anna DEI GIUDICI, Ambra CHIAPPINI, Santi CANNIZZARO,
Maria Teresa AFFERRI & Aurora DE CAROLIS
Division of Gastroenterology, Department of Internal Medicine and Medical Specialties, Sapienza University of
Rome, Rome, Italy
OBJECTIVE: Inadequate sun exposure impairs vita-
min D activity and favors low bone density, espe-
cially in patients at increased risk for osteoporosis,
such as those affected by inﬂammatory bowel disease
(IBD). In this study, sun exposure was investigated in
a large series of patients with IBD in a Mediterranean
country, Italy, where this risk is considered less likely
to occur than in higher latitudes.
METHODS: This is a case-control study of
292 patients with IBD [132 with Crohn’s disease
(CD) and 160 with ulcerative colitis (UC)], 80 dis-
eased and 540 healthy controls, conducted via a vali-
dated questionnaire to quantify sunlight exposure.
Data were also compared with controls matched by
age and gender.
RESULTS: In total 78 of the 292 patients with IBD
had low, 169 had moderate and 45 had high exposure
to sunlight, signiﬁcantly differing from controls
(P < 0.001). The 132 patients with CD were more
likely to have abnormal levels of sunlight exposure
(49 low, 72 moderate and 11 high) than those with
UC (29 low, 97 moderate and 34 high) (P < 0.001).
The controls were signiﬁcantly more exposed to sun-
light than both men and women with IBD (P < 0.001
and 0.004, respectively).
CONCLUSIONS: IBD patients are signiﬁcantly less
exposed to sunlight than matched controls in Italy,
often to an extent that may impair vitamin D activa-
tion. Increasing responsible sunlight exposure, thus
promoting adequate vitamin D concentrations, may
prove beneﬁcial in IBD, in geographical areas in which
this risk factor is not generally taken into consideration.
KEY WORDS: inﬂammatory bowel diseases, vitamin D, sunlight exposure, osteoporosis.
Vitamin D deﬁciency is frequent in adults and chil-
dren with inﬂammatory bowel disease (IBD), espe-
cially Crohn’s disease (CD).
Besides the well-
documented effects of vitamin D deﬁciency on bone
metabolism, the relationship between vitamin D and
IBD is complex and has been partially investigated
only. Indeed, the relative risk of being affected by CD,
but not ulcerative colitis (UC), is higher in northern
countries than in southern countries, with a north–
south gradient and is higher in areas characterized by
low exposure to sunlight.
Moreover, in the northern
Correspondence to: Giorgia BURRELLI SCOTTI, Department of Internal
Medicine and Medical Specialties, Sapienza University of Rome,
155, Viale del Policlinico, 00161, Rome, Italy.
Conﬂict of interest: None.
Accepted for publication 12 December 2017.
© 2017 Chinese Medical Association Shanghai Branch, Chinese
Society of Gastroenterology, Renji Hospital Afﬁliated to Shanghai
Jiaotong University School of Medicine and John Wiley & Sons
Journal of Digestive Diseases 2018; 19; 8–14 doi: 10.1111/1751-2980.12567