Abnormal expression of the vitamin D receptor in keloid scars

CYP24A1 is overexpressed in keloid keratinocytes and its inhibition alters profibrotic gene expression

Background

Keloids are disfiguring, fibrotic scar-like lesions that are challenging to treat and commonly recur after therapy. A deeper understanding of the mechanisms driving keloid formation is necessary for the development of more effective therapies. Reduced vitamin D receptor (VDR) expression has been observed in keloids, implicating vitamin D signaling in keloid pathology. Vitamin D exhibits anti-proliferative and anti-inflammatory properties, suggesting it could have therapeutic utility in keloid disorder. The current study investigated vitamin D-regulated gene expression in keloid keratinocytes and the effects of inhibiting an enzyme involved in vitamin D metabolism on the phenotype of keloid-derived keratinocytes.

Methods

Normal and keloid-derived primary keratinocytes were isolated from normal skin and keloid lesions, respectively, and were cultured in the absence or presence of vitamin D. In some experiments, inhibitors of the vitamin D metabolizing enzyme CYP24A1, ketoconazole or VID400 were added in the absence or presence of vitamin D. Cellular proliferation, migration and gene expression were measured.

Results

We observed significant overexpression of CYP24A1 mRNA in keloid versus normal keratinocytes and increased CYP24A1 protein levels in keloids versus normal skin. CYP24A1 encodes 24 hydroxylase and is induced by vitamin D in a feedback loop that regulates vitamin D levels; thus, inhibition of CYP24A1 activity may locally increase active vitamin D levels. Ketoconazole, a non-specific cytochrome P-450 inhibitor, reduced proliferation of keloid and normal keratinocytes, but VID400, a specific CYP24A1 inhibitor, only significantly affected keloid keratinocyte proliferation. Neither inhibitor significantly reduced keratinocyte migration. The two inhibitors had different effects on vitamin D target gene expression in keratinocytes. Specifically, ketoconazole treatment reduced CYP24A1 expression in normal and keloid keratinocytes, whereas VID400 increased CYP24A1 expression. Both inhibitors decreased expression of profibrotic genes, including periostin and hyaluronan synthase 2, in keloid-derived cells. Combined treatment of keloid keratinocytes with vitamin D and ketoconazole or VID400 increased the effects of vitamin D treatment on target genes, although the effects were gene- and cell type-specific.

Conclusions

The data suggest that reduction of vitamin D inactivation with CYP24A1 inhibitors may reduce profibrotic gene expression in keloid-derived cells. Therefore, CYP24A1 inhibitors may serve as adjunctive therapies to suppress keloid-associated gene expression changes.

Update on the Pathogenesis of Keloid Formation

Keloids are abnormal skin growths occurring in a significant portion of the global population. Despite their pervasiveness, the underlying pathophysiology of this scarring process is yet to be fully understood. In this review article, we delve into the current literature on the pathophysiological mechanisms of keloids. We take a top-down approach, first looking at host factors such as genetics and endocrine factors and then taking a more granular approach describing specific control factors such as germline keloid predisposition variants, epigenetics and transcriptomics, inflammatory and immune dysregulation, and the role of profibrotic and angiogenic cell signaling pathways. We then discuss current knowledge gaps, propose further research avenues, and explore potential future treatment options considering our increased understanding of keloid pathogenesis.

Global insights into keloid formation: An international systematic review of regional genetic risk factors and commonalities

Keloid disorder is a morbid and disfiguring benign fibroproliferative disease with a higher incidence in groups with darker skin pigmentation. Predicting keloidogenesis in patients is difficult with treatment primarily aimed at preventing further scar expansion and improving aesthetics without addressing their unknown underlying pathophysiology. We aimed to identify potential genetic predispositions to keloid scarring in the literature. A search was conducted on 21 August 2023, by the first and second authors independently from 1985 to August 2023 using PubMed, MEDLINE, Embase, Web of Science, Scopus and CINAHL. The following MeSH terms were used: 'Keloid', 'Risk' and 'Genetic'. Two researchers independently searched for studies based on titles and abstracts and screened filtered articles by reviewing full text. If no agreement could be reached, a third senior author designated whether the article should be included. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement as the basis of our organisation. Human studies with genetic analysis to determine an association of a protein or gene to keloidogenesis were selected for inclusion. Studies in languages other than English, reviews, conference articles, and book chapters were excluded. Fifty studies met inclusion criteria. The human leukocyte antigen (HLA) system was broadly implicated, and the DRB1*15 allele was associated with an increased risk of keloid in three separate ethnic groups. Some HLA Class I alleles were associated with keloid in one population but not in others. Additionally, polymorphisms in the E3 ubiquitin-protein ligase (NEDD4) signal cascade and vitamin D receptor (VDR) have been implicated in diverse groups. No current genetic test can predict keloid risk. Our review identified candidate predisposing genes, including NEDD4, VDR and components of the HLA system. Further studies in heterogeneous populations are needed to identify reliable screening targets.

A double-blinded randomised control study to compare the effectiveness and safety of intralesional vitamin D3 with intralesional triamcinolone and its correlation with tissue expression of vitamin D receptors in patients with keloid

Intralesional steroids commonly used for keloid treatment have adverse effects like cutaneous atrophy and telangiectasias. Safer and more effective therapies are needed. Preliminary studies suggest intralesional vitamin D as a potential alternative treatment. The aim of this study was to compare efficacy and safety of intralesional vitamin D with triamcinolone for keloids, and correlate tissue expression of vitamin D receptors (VDRs) with treatment outcomes. Sixty patients were randomly assigned to two groups: Group A (intralesional vitamin D) and Group B (intralesional triamcinolone). Four injections were given at 4-week intervals, with an 8-week follow-up. Biopsies were taken pre- and post-treatment to examine VDR expression levels and treatment response correlation. The primary outcome of interest was the proportion of patients achieving a 50% reduction in Vancouver Scar Scale (VSS). Secondary outcomes included incidence of adverse effects, and changes in VDR expression before and after treatment. Baseline VSS scores were 9.73 ± 1.01 (vitamin D group) and 10.13 ± 1.07 (triamcinolone group). After treatment, mean VSS decreased to 5.17 ± 0.59 (vitamin D group, p < 0.001) and 4.77 ± 0.77 (triamcinolone group, p < 0.001), with significantly better response in latter (p = 0.03). More than 50% reduction in VSS score was higher in the triamcinolone group (76.7% vs. 50%, p = 0.032). No recurrences were noted during the 8-week follow-up. Hypopigmentation (80% vs. 36.7%, p < 0.001) and atrophy (73.3% vs. 40%, p = 0.009) were more common in the triamcinolone group. No significant difference in pre- and post-treatment VDR receptor expression was observed in either group. Both triamcinolone acetonide and vitamin D were effective for keloids. Triamcinolone was more efficacious, whereas vitamin D was safer, suggesting it as a viable alternative for keloid management.

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Metabolism, fibrosis, and apoptosis: The effect of lipids and their derivatives on keloid formation

Keloids, pathological scars resulting from skin trauma, have traditionally posed significant clinical management challenges due to their persistence and high recurrence rates. Our research elucidates the pivotal roles of lipids and their derivatives in keloid development, driven by underlying mechanisms of abnormal cell proliferation, apoptosis, and extracellular matrix deposition. Key findings suggest that abnormalities in arachidonic acid (AA) synthesis and non-essential fatty acid synthesis are integral to keloid formation. Further, a complex interplay exists between lipid derivatives, notably butyric acid (BA), prostaglandin E2 (PGE2), prostaglandin D2 (PGD2), and the regulation of hyperfibrosis. Additionally, combinations of docosahexaenoic acid (DHA) with BA and 15-deoxy-Δ12,14-Prostaglandin J2 have exhibited pronounced cytotoxic effects. Among sphingolipids, ceramide (Cer) displayed limited pro-apoptotic effects in keloid fibroblasts (KFBs), whereas sphingosine 1-phosphate (S1P) was found to promote keloid hyperfibrosis, with its analogue, FTY720, demonstrating contrasting benefits. Both Vitamin D and hexadecylphosphorylcholine (HePC) showed potential antifibrotic and antiproliferative properties, suggesting their utility in keloid management. While keloids remain a prevalent concern in clinical practice, this study underscores the promising potential of targeting specific lipid molecules for the advancement of keloid therapeutic strategies.

Possible benefits of food supplementation or diet in scar management: A scoping review

Aim

The evidence regarding a potential role of food supplementation as an adjunct therapy in scar aftercare is limited. In this scoping review we aim to provide an overview of the possible beneficial role of supplementations in aftercare settings.

Method

After formulating the research question and accompanying key words, a comprehensive search for relevant publications was performed using PubMed and Web of Science. Two authors independently identified and checked each study against the inclusion criteria. All data was collected and summarized for further discussion.

Results

After screening, 11 studies were included in the qualitative synthesis. Four studies including human subjects showed a promising connection between scar improvement and supplementation of vitamin D, omega-3 fatty-acids or a Solanaceae-free diet and lower omega-6 fatty-acid intake. Most of the studies were performed on in-vitro models. Preliminary evidence confirmed the beneficial role of vitamin D. Curcumin- and quercetin-supplementation were linked to decreased fibroblast proliferation. Vitamin C enhanced collagen production in healthy as well as keloidal dermal fibroblasts. Chitin stimulated cell-proliferation in human fibroblasts and keratinocytes.

Conclusion

The findings suggest early potential benefits of additional food supplementation in scar management for scars but provide no clear evidence. To establish guidelines or gather more evidence on food supplementation, studies involving human subjects (in vivo) are essential. The intricacies associated with nutritional studies in vivo present multifaceted challenges. It should be emphasized that substantial additional evidence is required before aspects such as timing and dosage of supplementation could be addressed for clinical application.

Lay Summary

Aim: This scoping review looks at whether taking food supplements might help with scar care alongside standard scar management following burn injury. Little information is thought to be available on this subject. An up-to-date review of the literature was undertaken to assimilate the body of evidence and determine if a consensus could be drawn.Method: A specific research question was designed and search conducted in scientific databases like PubMed and Web of Science. Two of our team members carefully selected and reviewed each study to determine which studies met the inclusion or exclusion criteria. All studies that met the inclusion criteria were then reviewed and the information collated to enable conclusions to be drawn.Results: Eleven studies met the inclusion criteria and were used to formulate the conclusions drawn. Four studies showed that taking vitamin D, omega-3 fatty acids, a diet without certain vegetables (Solanaceae), and eating less omega-6 fatty acids might help improve scars. It is important to note that most studies (seven out of 11) were carried out in a laboratory and not with real people. These lab studies showed that vitamin D might be helpful. Supplements like curcumin and quercetin seemed to slow down the growth of skin cells like fibroblasts and keratinocytes. Vitamin C aided collagen synthesis, which is important for healthy skin, in both normal and keloid scar cells. Another substance, chitin, was also found to help skin cells and keratinocytes grow better.Conclusion: Our findings point to some early possible benefits of taking extra nutrient supplements for managing scars but do not provide clear evidence. More research is required to enable the development of supplement recommendation and guidelines to be produced. Future research should focus on human trials but do keep in mind that carrying out supplement studies with people is more complicated. The evidence provided by this scoping review is insufficient to recommend the intake of any supplements or the imposition of dietary restrictions for the purpose of managing scars.

Progress in the clinical treatment of keloids

Keloid is a pathological scar that is higher than the skin surface following skin damage. Its lesion range often extends beyond the original damage boundary and does not naturally subside over time. Its pathogenesis is very complex, currently the main causes include fibroblast excessive proliferation, collagen and extracellular matrix (Extracellular matrix, ECM) excessive deposition, excessive angiogenesis, and so on. The traditional treatment method primarily involves surgical intervention, but it is associated with a high recurrence rate post-surgery. Consequently, many treatment methods are derived according to the different clinical characteristics of keloid. This paper will review the therapeutic progress in recent years from surgical treatment, physiotherapy, drug therapy, and biological therapy, with the goal of offering valuable insights for the clinical treatment of keloids.

A role for vitamin D and the vitamin D receptor in keloid disorder

Keloids are disfiguring fibroproliferative lesions that can occur in susceptible individuals following any skin injury. They are extremely challenging to treat, with relatively low response rates to current therapies and high rates of recurrence after treatment. Although several distinct genetic loci have been associated with keloid formation in different populations, there has been no single causative gene yet identified and the molecular mechanisms guiding keloid development are incompletely understood. Further, although it is well known that keloids are more commonly observed in populations with dark skin pigmentation, the basis for increased keloid risk in skin of colour is not yet known. Because individuals with dark skin pigmentation are at higher risk for vitamin D deficiency, the role of vitamin D in keloid pathology has gained interest in the keloid research community. A limited number of studies have found lower serum vitamin D levels in patients with keloids, and reduced expression of the vitamin D receptor (VDR) in keloid lesions compared with uninjured skin. Vitamin D has documented anti-inflammatory, anti-proliferative and pro-differentiation activities, suggesting it may have a therapeutic role in suppression of keloid fibrosis. Here we review the evidence supporting a role for vitamin D and VDR in keloid pathology.

Involucrin Modulates Vitamin D Receptor Activity in the Epidermis

Terminally differentiated keratinocytes are critical for epidermal function and are surrounded by involucrin (IVL). Increased IVL expression is associated with a near-selective sweep in European populations compared with those in Africa. This positive selection for increased IVL in the epidermis identifies human adaptation outside of Africa. The functional significance is unclear. We hypothesize that IVL modulates the environmentally sensitive vitamin D receptor (VDR) in the epidermis. We investigated VDR activity in Ivl‒/‒ and wild-type mice using vitamin D agonist (MC903) treatment and comprehensively determined the inflammatory response using single-cell RNA sequencing and associated skin microbiome changes using 16S bacterial phylotyping. VDR activity and target gene expression were reduced in Ivl‒/‒ mouse skin, with decreased MC903-mediated skin inflammation and significant reductions in CD4+ T cells, basophils, macrophages, monocytes, and type II basal keratinocytes and an increase in suprabasal keratinocytes. Coinciding with the dampened MC903-mediated inflammation, the skin microbiota of Ivl‒/‒ mice was more stable than that of the wild-type mice, which exhibited an MC903-responsive increase in Bacteroidetes and a decrease in Firmicutes. Together, our studies in Ivl‒/‒ mice identify a functional role for IVL to positively impact VDR activity and suggest an emerging IVL/VDR paradigm for adaptation in the human epidermis.

In-depth examination of hyperproliferative healing in two breeds of Sus scrofa domesticus commonly used for research

Background

Wound healing can result in various outcomes, including hypertrophic scar (HTS). Pigs serve as models to study wound healing as their skin shares physiologic similarity with humans. Yorkshire (Yk) and Duroc (Dc) pigs have been used to mimic normal and abnormal wound healing, respectively. The reason behind this differential healing phenotype was explored here.

Methods

Excisional wounds were made on Dc and Yk pigs and were sampled and imaged for 98 days. PCR arrays were used to determine differential gene expression. Vancouver Scar Scale (VSS) scores were given. Re-epithelialization was analyzed. H&E, Mason's trichrome, and immunostains were used to determine cellularity, collagen content, and blood vessel density, respectively.

Results

Yk wounds heal to a "port wine" HTS, resembling scarring in Fitzpatrick skin types (FST) I-III. Dc wounds heal to a dyspigmented, non-pliable HTS, resembling scarring in FST IV-VI. Gene expression during wound healing was differentially regulated versus uninjured skin in 40/80 genes, 15 of which differed between breeds. Yk scars had a higher VSS score at all time points. Yk and Dc wounds had equivalent re-epithelialization, collagen disorganization, and blood vessel density.

Conclusions

Our findings demonstrate that Dc and Yk pigs can produce HTS. Wound creation and healing were consistent among breeds, and differences in gene expression were not sufficient to explain differences in resulting scar phenotype. Both pig breeds should be used in animal models to investigate novel therapeutics to provide insight into a treatment's effectiveness on various skin types.

Pathologic Scarring after Eyebrow Micropigmentation: A Case Report and Systematic Review

BACKGROUND

Skin tattooing and cosmetic eyebrow definition and reshaping (micropigmentation) have been growing exponentially in popularity. The pigment used in these procedures can activate the skin's inflammatory response, promoting the formation of pathologic scars.

OBJECTIVE

To carry out a systematic review of the literature on this topic and report a case of pathologic scarring on the eyebrows after micropigmentation.

METHODS

A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline in the MEDLINE, Lilacs, and SciELO databases using the keywords "scar; scar, hypertrophic; eyebrows; pigmentation; skin pigmentation; coloring agents; tattooing" and their synonyms.

RESULTS

The systematic literature review did not identify any study reporting pathologic scarring on eyebrows after micropigmentation. This is likely because eyebrow pathology is uncommon, although these results are limited by the comprehensiveness of the systematic review. The case of a 50-year-old woman undergoing eyebrow micropigmentation who presented with hypertrophic scarring after the procedure is also reported.

CONCLUSIONS

Eyebrow micropigmentation may be a risk factor for pathologic scarring, but further research is needed.

Role of vitamin D in treatment of keloid

BACKGROUND

Keloid is a benign well-demarcated overgrowth of fibrotic tissue which extends beyond the original boundaries of a defect. The treatment of keloids is a particular challenge to dermatologists. Intralesional corticosteroid injection has been considered the first-line treatment for keloids. Vitamin D plays an important role in cell proliferation and differentiation as it slows the progression of tissue fibrosis by keloid fibroblasts and inhibits collagen synthesis in dermal fibrosis.

OBJECTIVES

To evaluate the efficacy of intralesional injection of vitamin D in the treatment of keloids, both clinically and ultrasonically.

METHODS

Forty Egyptian patients with keloid scars were injected weekly with intralesional vitamin D with dose of 0.2 ml (200,000 IU) per 1 cm lesion. The keloid scars were evaluated with Vancouver Scar Scale (VSS) and by a high-resolution ultrasound using B mode before and after treatment, the patients received 3 to 4 sessions.

RESULTS

There was statistically highly significant reduction in VSS after treatment with intralesional vitamin D injection (p value≤0.001). There was also statistically highly significant improvement in ultrasonic keloid scar thickness after treatment (P value ≤0.001).

CONCLUSIONS

Intralesional vitamin D is an effective and safe method in treatment of keloid scars. Ultrasound is a useful method in assessing the improvement of keloids after treatment.

Does vitamin D deficiency predispose to keloids via dysregulation of koebnerisin (S100A15)? A case-control study

Keloids result from uncontrolled inflammation and fibrosis during wound healing. Vitamin D can regulate skin proliferation and inflammation. Fibroblasts are vitamin D-responsive target cells and are source of koebnerisin (an antimicrobial peptide released during inflammation and wound healing). This study aimed to assess the levels and correlations between the serum and tissue 25-Hydroxyvitamin D, tissue vitamin D receptors, and serum and tissue koebnerisin (S100A15) in patients with keloids. Nineteen patients with keloids and 20 matched controls were recruited. From each keloid patient, a serum sample and two biopsies were taken from the keloid (lesional) (Tissue A) and from normal skin (non-lesional) (Tissue B). From controls, a serum sample and a tissue biopsy from normal skin were taken. Serum and tissue 25-Hydroxyvitamin D, tissue vitamin D receptors, and serum and tissue koebnerisin were measured in retrieved samples using ELISA. Results revealed a significantly lower serum 25-Hydroxyvitamin D, tissue vitamin D receptors, as well as, serum and tissue koebnerisin in keloid patients compared to controls. Tissue 25-Hydroxyvitamin D was significantly lower in keloidal skin biopsy (Tissue A) compared to non-lesional normal skin biopsy (Tissue B). Tissue koebnerisin showed a significant positive correlation with tissue vitamin D receptors, and a significant negative correlation with tissue 25-Hydroxyvitamin D. There was a significant negative correlation between serum 25-Hydroxyvitamin D and duration of keloid. Accordingly, low serum and tissue 25-Hydroxyvitamin D and deficient tissue vitamin D receptors contribute to the pathogenesis of keloids. This can be partly mediated by dysregulation of the antimicrobial peptide; koebnerisin. Artificial antimicrobial peptides and koebnerisin-modifying drugs, for example, vitamin D and TNF-α inhibitors can have a role in keloid prevention and treatment.

The Role of the Renin-Angiotensin System and Vitamin D in Keloid Disorder-A Review

Keloid disorder (KD) is a fibroproliferative condition characterized by excessive dermal collagen deposition in response to wounding and/or inflammation of the skin. Despite intensive research, treatment for KD remains empirical and unsatisfactory. Activation of the renin-angiotensin system (RAS) leads to fibrosis in various organs through its direct effect and the resultant hypertension, and activation of the immune system. The observation of an increased incidence of KD in dark-skinned individuals who are predisposed to vitamin D deficiency (VDD) and hypertension, and the association of KD with hypertension and VDD, all of which are associated with an elevated activity of the RAS, provides clues to the pathogenesis of KD. There is increasing evidence implicating embryonic-like stem (ESC) cells that express ESC markers within keloid-associated lymphoid tissues (KALTs) in keloid lesions. These primitive cells express components of the RAS, cathepsins B, D, and G that constitute bypass loops of the RAS, and vitamin D receptor (VDR). This suggests that the RAS directly, and through signaling pathways that converge on the RAS, including VDR-mediated mechanisms and the immune system, may play a critical role in regulating the primitive population within the KALTs. This review discusses the role of the RAS, its relationship with hypertension, vitamin D, VDR, VDD, and the immune system that provide a microenvironmental niche in regulating the ESC-like cells within the KALTs. These ESC-like cells may be a novel therapeutic target for the treatment of this enigmatic and challenging condition, by modulating the RAS using inhibitors of the RAS and its bypass loops and convergent signaling pathways.

Crosstalk among adipose tissue, vitamin D level, and biomechanical properties of hypertrophic burn scars

PURPOSE

This cross-sectional study aimed to investigate whether adipose tissue loss and reduced vitamin D levels following severe burn injury are associated with pathologic scar formation and biomechanical scar properties.

METHODS

A total of 492 male subjects with hypertrophic burn scars were enrolled from January 2014 to July 2018 and analyzed. Body fat content was measured using dual-energy X-ray absorptiometry. Values of melanin, erythema, and trans-epidermal water loss (TEWL) and the distensibility and elasticity of hypertrophic scars were examined using pigment- and TEWL-measuring devices and a suction skin elasticity meter.

RESULTS

Burn patients with higher fat percentage tended to have higher 25(OH) vitamin D levels (P < 0.001). As body fat percentage increased, hypertrophic scars showed higher mean value of Uf (distensibility, P < 0.001) and lower mean value of Uv/Ue (viscoelasticity or interstitial fluid shifting, P < 0.001). Burn patients with higher 25(OH) vitamin D levels tended to have higher mean values of Uf (P < 0.001) and Ua/Uf (gross elasticity, P = 0.013) and lower mean value of Uv/Ue (P = 0.008).

CONCLUSION

Adipose tissue loss and decreased 25(OH) vitamin D levels following burn injury were related to scar rigidity and slow interstitial fluid shifting in hypertrophic scars.

The Association Between Postburn Vitamin D Deficiency and the Biomechanical Properties of Hypertrophic Scars

Fibroblasts, keratinocytes, mast cells, and other cells participate in hypertrophic scar formation and express the vitamin D receptor. We investigated the association between vitamin D deficiency and the biomechanical properties of hypertrophic burn scars. This cross-sectional study analyzed 486 participants enrolled from May 1, 2013 to April 30, 2017. When complete wound healing was agreed with by the two opinions, blood sampling and scar evaluation were performed. The values of melanin and erythema, trans-epidermal water loss (TEWL), and scar distensibility and elasticity were measured using pigment- and TEWL-measuring devices and a suction skin elasticity meter. 25(OH) vitamin D deficiency was defined as plasma level of <20 ng/ml. The vitamin D-deficient patients had significantly higher mean values of scar melanin and TEWL (P = .032, P = .007), whereas scar erythema level was similar. They also showed significantly lower values of Uf (final distensibility; P < .001), Ua/Uf (gross elasticity; P < .001) and Ur/Uf (biological elasticity; P = .014), and higher value of Uv/Ue (viscoelasticity or potency against interstitial fluid shift; P = .016). In multiple linear regression analysis, Uf, Ua/Uf, Uv/Ue, and Ur/Uf were significantly affected by 25(OH)-vitamin D level in deficient patients (Uf, P = .017; Ua/Uf, P = .045; Uv/Ue, P = .024; Ur/Uf, P = .021). Our results demonstrated that vitamin D deficiency was significantly related to increased pigmentation, decreased skin barrier function, low scar distensibility and elasticity, and slow interstitial fluid movement in burn patients.