vitamin D is one of the essential metabolic and physiological processes in the human body. Generally all people need 200-600 IU daily (Koutkia, Chen & Holick 2001). Production of vitamin D in the skin depends on some factors such as age, skin pigmentation and the amount of ultraviolet B (UVB)) available. The amount of UVB radiation is affected by geographic location, season, time and level of atmospheric pollution. The highest amount of vitamin D is provided to sunlight exposure (Gartner & Greer 2003) as well as obtaining from oily fish, fortified foods and supplement. The recommended vitamin D receiving depends on age, gender and deficiency treatment (Dobnig et al 2008).

Background: Chronic urticarial is one of the most common skin diseases, characterized by as a chronic cutaneous condition which severely debilitates patients in several aspects of their everyday life. CU patients suffer from physical, social, and psychological morbidities resulting in a low quality of life. vitamin D is known to exert several actions in the immune system and to influence function and differentiation of mast cells, central role players in the pathogenesis of chronic idiopathic urticarial. Recently, an increasing body of literature showed paradoxical relationships between vitamin D and allergic diseases like food allergy, rhinosinusitis, recurrent wheeze, asthma, atopic dermatitis and eczema. This study was performed to evaluate the relationship between vitamin D levels and susceptibility to chronic idiopathic urticarial.Methods: One hundred and fourteen patients with chronic idiopathic rticarial were recruited in this study along with one hundred and eighty seven sex-matched and age-matched healthy volunteers as the control group. For each patient, urticarial activity score was calculated and autologous serum skin test was done. vitamin D metabolic statue was measured as 25 hydroxyvitamin D using enzyme immunoassay method.Findings: Patients with chronic idiopathic urticarial significantly had lower levels of vitamin D (p<0.01). vitamin D deficiency was significantly associated with increased susceptibility to chronic idiopathic urticarial (p<0.01). There was a significant positive correlation between vitamin D levels and urticarial activity score (r=0.2, p<0.05).Conclusion: This study showed patients with chronic idiopathic rticarial had reduced levels of vitamin D, while vitamin D deficiency could increase susceptibility to chronic idiopathic urticarial.

Chronic urticaria is the most common skin disease, characterized by chronic cutaneous lesions which severely debilitates patients in several aspects of their everyday life. vitamin D is known to exert several actions in the immune system and to influence function and differentiation of mast cells, central role players in the pathogenesis of chronic idiopathic urticaria.This study was performed to evaluate the relationship between vitamin D levels and susceptibility to chronic idiopathic urticaria. One hundred and fourteen patients with chronic idiopathic urticaria were recruited in this study along with one hundred and eighty seven sex-matched and age-matched healthy volunteers as the control group. For each patient, urticaria activity score was calculated and autologous serum skin test was done.vitamin D metabolic statue was measured in serum as 25 hydroxyvitamin D using enzyme immunoassay method. Patients with chronic idiopathic urticaria significantly showed lower levels of vitamin D. vitamin D deficiency was significantly associated with increased susceptibility to chronic idiopathic urticaria. There was a significant positive correlation between vitamin D levels and urticaria activity score.This study showed that patients with chronic idiopathic urticaria had reduced levels of vitamin D, while vitamin D deficiency could increase susceptibility to chronic idiopathic urticaria.