Vitamin D in the skin physiology and pathology.

Abstract

Vitamin D plays important, pleiotropic role in the maintenance of global homeostasis. Its influence goes far beyond the regulation of calcium and phosphorus balance, as diverse activities of vitamin D and its natural metabolites assure proper functioning of major human organs, including skin. Recently, we reviewed the current understanding of vitamin D impact on human health from historical perspective (Wierzbicka et al. (2014) The renaissance of vitamin D. Acta Biochim Pol 61: 679-686). This article focuses on its functions in the skin. The skin and its appendages, creates a platform connecting and protecting internal organs against, usually harmful, external environment. It uppermost layer - epidermis in order to maintain a protective barrier undergoes a constant exchange of cornified keratinocytes layer. Its disturbance leads to development of serious skin disorders including psoriasis, vitiligo, atopic dermatitis and skin cancer. All of those dermatopathologies have a huge impact on modern societies, affecting not only the physical, but also mental state of patients as well as their social status. Furthermore, multiple human systemic diseases (autoimmune, blood and digestive diseases) have skin manifestation, thus "condition of the skin" often reflects the condition and pathological changes within the internal organs. In humans, the skin is the natural source of vitamin D, which is produced locally from 7-dehydrocholesterol in photoreaction induced by ultraviolet B (UVB) radiation from the sun. It is also well established, that the process of proliferation and differentiation of keratinocytes is tightly regulated by calcium and the active form of vitamin D (1,25(OH)2D3). Thus, the skin physiology is inseparably connected with vitamin D production and activity. Unfortunately, UVB, which is required for vitamin D production, is also known as the main cause of a skin cancer, including melanoma. Here, we are going to review benefits of vitamin D and its analogues in the maintenance of epidermal barrier and its potential use in the treatment of common skin diseases.

Differentiation of Keratinocytes Modulates Skin HPA Analog

“…Keratinocyte differentiation is a complex process, which is essential for proper renewal of an epidermal barrier (Fuchs and Raghavan, 2002;Eckhart et al, 2013). This process is tightly regulated by the calcium and vitamin D, and it is accompanied by the modulation of the expression of multiple genes (Bikle, 2011;Elias et al, 2013;Piotrowska et al, 2016). It is now well established that in an addition to its mechanical and biophysical properties, skin also has neuroendocrine functions (Zmijewski and Slominski, 2011;Slominski et al, 2012Slominski et al, , 2013b.…”

Immunohistochemical expression of vitamin D receptor in melanocytic naevi and cutaneous melanoma: a case-control study

“…found expression of VD receptor (VDR) in MM cells, and showed that VD exposure dramatically reduces cell proliferation in a dose–response manner . Since then, new findings have shown that VD inhibits in vitro proliferation, induces differentiation and inhibits angiogenesis and invasion of MM cells with a protective antineoplastic effect in vitro …”

“…8 Since then, new findings have shown that VD inhibits in vitro proliferation, induces differentiation and inhibits angiogenesis and invasion of MM cells with a protective antineoplastic effect in vitro. 9 Brozyna et al evaluated VDR staining in normal skin, different types of naevi and MM, showing a negative correlation between tumour immunohistochemical VDR expression and progression of pigmented skin lesions. In that study, VDR immunoreactivity was stronger in normal skin than in naevi, higher in naevi than in MM and equal between MM and MM metastasis.…”

Bactericidal effects of 310 nm ultraviolet light-emitting diode irradiation on oral bacteria

“…UVB irradiation converts vitamin D from its inactive form to active form in the epithelium [41, 42]. The amount of 1α-hydroxylase, an enzyme that converts vitamin D to its active form, is increased by UVB irradiation in the skin [43].…”