Vitamin D, a hormone synthesized in the skin through ultraviolet B radiation (UVB), plays a crucial role not only in calcium and phosphate homeostasis but also in regulating skin homeostasis and modulating immune responses. In keratinocytes, vitamin D is converted to its active form, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D), which interacts with the vitamin D receptor (VDR) to regulate gene expression involved in proliferation, differentiation, and antimicrobial defense. Dysregulation of this pathway has been implicated in inflammatory skin diseases such as psoriasis, atopic dermatitis, acne vulgaris, and hidradenitis suppurativa. These conditions are associated with altered epidermal differentiation, immune imbalance, and microbial interactions, where vitamin D plays a modulatory role by suppressing proinflammatory cytokines, enhancing antimicrobial peptide synthesis, and restoring skin barrier integrity. Topical vitamin D analogues have shown therapeutic benefits in psoriasis, while emerging evidence supports the adjunctive role of vitamin D supplementation in acne, hidradenitis suppurativa, and atopic dermatitis. Despite promising associations between low serum vitamin D levels and disease severity, a causal relationship remains uncertain. This review integrates molecular mechanisms with clinical findings, emphasizing the role of vitamin D in cutaneous physiology and pathology, and highlights the need for further research into targeted supplementation strategies in dermatological disorders.

Epidermolysis bullosa acquisita (EBA) is a rare chronic autoimmune subepidermal blistering disease of the skin and mucous membranes, usually beginning in adulthood. EBA is induced by autoantibodies to type VII collagen, a major component of anchoring fibrils in the dermal–epidermal junction (DEJ). The binding of autoantibodies to type-VII collagen subsequently leads to the detachment of the epidermis and the formation of mucocutaneous blisters. EBA has two major clinical subtypes: the mechanobullous and inflammatory variants. The classic mechanobullous variant presentation consists of skin fragility, bullae with minimal clinical or histological inflammation, erosions in acral distribution that heal with scarring, and milia formation. The inflammatory variant is challenging to differentiate from other autoimmune bullous diseases, most commonly bullous pemphigoid (BP) but also mucous membrane pemphigoid (MMP), Brunsting–Perry pemphigoid, and linear IgA dermatosis. Due to its recalcitrance conventional treatment of epidermolysis bullosa acquisita is shown to be demanding. Here we discuss novel therapeutic strategies that have emerged and which could potentially improve the quality of life in patients with EBA.

According to recent data, one in eight people in the world struggle with obesity. Obesity management is increasingly dependent on bariatric surgical interventions, as the combination of lifestyle modifications and pharmacotherapy could have a modest long-term effect. Surgery is recommended only for individuals whose body mass index (BMI) ≥ 40 kg/m² and ≥ 35 kg/m² in the presence of weight-related comorbidities. The most commonly performed procedures are sleeve gastrectomy and roux-en-Y gastric bypass. Pharmacokinetic and pharmacodynamic alterations occur as a result of the anatomical and physiological changes caused by surgery, which further differ depending on physicochemical drug factors and factors related to the dosage form. The following modifications are distinguished based on the type of bariatric surgery performed. Most bariatric patients have accompanying comorbidities, including dyslipidemia treated with hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins. Significant improvements in the lipid profile are observed early in the postoperative period. The data reported in this review on statin pharmacokinetic alterations have demonstrated substantial inter- and intravariability, making it difficult to adopt clear guidelines. Based on the current literature review, reducing the statin dose to the lowest effective with continuous monitoring is considered an optimal approach in clinical practice.