Serum 25-hydroxy vitamin D3 level in Egyptian patients with alopecia areata Naglaa N. El-Mongy a , Eman El-Nabarawy a , Shahenda A. Hassaan c , Eman R. Younis d and Olfat Shaker b Departments of a Dermatology, b Medical Biochemistry, Cairo University, Departments of c Dermatology and d Biochemistry, National Research Centre, Cairo, Egypt Correspondence to Naglaa N. El-Mongy, 35 Dokki Street, Apt. 111, 12311 Giza, Egypt Tel: +20 100 171 3196; fax: +20 223 687 673; e-mail: nnradw@yahoo.com Received 21 May 2012 Accepted 25 July 2012 Journal of the Egyptian Women’s Dermatologic Society 2013, 10:37–41 Background Vitamin D has multiple effects on innate and adaptive immune responses. The relation between vitamin D levels and alopecia areata (AA), a tissue-specific autoimmune disease, represents an attractive area of research. Objective The objective of the study was to estimate the serum level of 25-hydroxy vitamin D (25-OH Vit D) in AA patients and explore a probable relation. Patients and methods A total of 140 individuals from the Egyptian population were recruited into a case– control study, of whom 70 were patients with AA of various types and 70 were healthy controls. Serum 25-OH Vit D levels were measured. Correlations with disease duration and severity, positive family history, age and sex were made. Results AA patients comprised 37 male and 33 female patients (13–50 years). The healthy controls comprised 44 male and 26 female individuals (12–50 years). Serum 25-OH Vit D levels were significantly decreased in AA patients than in controls (P = 0.023). The female participants in both groups (patients and controls) showed significantly lower vitamin D levels compared with male participants (P = 0.005). There was no significant relationship between serum 25-OH Vit D levels and age, duration, severity or positive family history. Conclusion AA is associated with low levels of 25-OH Vit D, especially in female participants. More studies are required to prove its possible role in AA pathogenesis. Keywords: adaptive immunity, alopecia areata, autoimmunity, innate immunity, vitamin D J Egypt Women Dermatol Soc 10:37–41 & 2013 Egyptian Women’s Dermatologic Society 1687-1537 Introduction Alopecia areata (AA) is a tissue-restricted autoimmune disease mediated by T lymphocytes with a Th1 cytokine profile [1]. AA occurs mostly in genetically predisposed individuals triggered by environmental factors [2]. There is evidence for loss of immune privilege coupled with T-cell- mediated attack of hair follicle autoantigens, as well as for the role of autoantibodies in the pathogenesis of AA [1]. Interferon-g, interleukins (IL) and tumor necrosis factor-a are cytokines that are known to have a major role in the pathogenesis of the disease [3]. CD8 + T cells are considered to act as effector cells with help from CD4 + T cells [4]. The analysis of the skin of mice with chronic AA and of mice receiving a transplant of AA-affected skin suggests that autoaggression is due to a defect in regulatory T cells [5]. Many autoimmune conditions have been associated with reduced vitamin D levels [6]. However; little is known about the association between AA and reduced vitamin D levels. Vitamin D is a steroid hormone synthesized in epidermal keratinocytes under the influence of UV-B light or acquired from diet and dietary supplements [7]. The active form of vitamin D, 1,25-dihydroxyvitamin D3 [1,25(OH)2 Vit D3], has multiple effects on innate and adaptive immune responses through its varied effects on T and B lymphocytes, macrophages and dendritic cells (DCs), all of which express vitamin D receptors (VDRs) [6]. As such, the impact of vitamin D on human physiology and disease is broad and there is wide interest in the role of this hormone in many areas of medicine [8]. Determination of vitamin D status is not based on measurement of serum 1,25(OH)2 Vit D3 concentrations. It is assessed by measuring the prohor- mone 25-hydroxy vitamin D (25-OH Vit D), which is an indicator of supply rather than function. The most stable and plentiful metabolite of vitamin D in human serum is 25-OH Vit D, which has a half-life of about 3 weeks, making it the most suitable indicator of the vitamin D status [9]. The study aimed at the evaluation of serum 25-OH Vit D levels in patients with AA in an attempt to identify any possible relation in the pathogenesis of the disease. Original article 37 1687-1537 & 2013 Egyptian Women’s Dermatologic Society DOI: 10.1097/01.EWX.0000419612.74665.2b Copyright © Egyptian Women’s Dermatologic Society. Unauthorized reproduction of this article is prohibited.