Serum 25 hydroxyvitamin D levels in alopecia areata, female pattern hair loss, and male androgenetic alopecia in a Chinese population

Serum 25 hydroxyvitamin D in non-scarring alopecia: A systematic review and meta-analysis

INTRODUCTION

Non-scarring alopecia mainly includes androgenetic alopecia (AGA), female pattern hair loss (FPHL), alopecia areata (AA), telogen effluvium (TE), anagen effluvium (AE) and so on. Many studies had investigated the serum 25-hydroxyvitamin D level and vitamin D deficiency of patients with these diseases, but opinions varied, and no conclusion was reached.

METHODS

Relevant articles were retrieved through PubMed, Web of Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI) and other databases. Serum 25-hydroxyvitamin D [25(OH) D] levels and vitamin D deficiency were used as our primary outcome. The odds ratio (OR) and the standardized mean difference (SMD) with 95% confidence interval were both examined for vitamin D deficiency and levels.

RESULTS

Our meta-analysis had included a total of 3374 non-scarring alopecia patients and 7296 healthy controls from 23 studies through the inclusion criteria and exclusion criteria. We found non-scarring alopecia had decreased serum 25(OH)D level (WMD -7.29; 95% CI -9.21, -5.38) and increased vitamin D deficiency incidence (OR 3.11 95% CI 2.29, 4.22), compared with healthy controls. This meta-analysis chose to conduct random-effect model and subgroup analysis, because of the high heterogeneity (serum 25(OH)D level: I2 = 95%, vitamin D deficiency: I2 = 0%).

CONCLUSION

Patients with non-scarring alopecia (including AA, FPHL, AGA and TE) have insufficient serum level of 25(OH)D and increased incidence of vitamin D deficiency. Vitamin D supplementation and monitoring for vitamin D deficiency may be helpful in treating non-scarring alopecia.

mTOR signaling in hair follicle and hair diseases: recent progress

Mammalian target of rapamycin (mTOR) signaling pathway is a major regulator of cell proliferation and metabolism, playing significant roles in proliferation, apoptosis, inflammation, and illness. More and more evidences showed that the mTOR signaling pathway affects hair follicle circulation and maintains the stability of hair follicle stem cells. mTOR signaling may be a critical cog in Vitamin D receptor (VDR) deficiency-mediated hair follicle damage and degeneration and related alopecia disorders. This review examines the function of mTOR signaling in hair follicles and hair diseases, and talks about the underlying molecular mechanisms that mTOR signaling regulates.

Prevalence of Low Serum Vitamin D Levels in Patients Presenting With Androgenetic Alopecia: A Review

The role of vitamin D receptor (VDR) has been well established and extensively studied in the hair cycle. Its deficiency is also closely linked to several types of alopecia, including alopecia areata, telogen effluvium, and androgenetic alopecia (AGA). Since there is limited research on the correlation between androgenetic alopecia and low serum vitamin D levels, our review aims to find relevant articles and comprehensively present them. A review of the literature was performed to gain insight into AGA. Specifically, PubMed and Google Scholar databases were searched to identify any relevant articles with a focus on androgenetic alopecia, male pattern baldness, and serum vitamin D levels. References within the included articles were also reviewed and taken into the study if found appropriate. All articles that met the inclusion criteria were analyzed for demographics, clinical, laboratory, radiographic, treatment, and outcomes data. We found 13 relevant studies that elucidated the relationship between low serum vitamin D levels and androgenetic alopecia and included them in the review. We concluded that serum vitamin D might be a possible parameter for diagnosing the onset and severity of AGA. Vitamin D supplementation has proven to be useful in the regrowth of hair in non-human subjects. Vitamin D could be a valid therapeutic approach, such as topical vitamin D (calcipotriol) seems to be a good treatment option to regrow hair follicles and prevent miniaturization of follicles due to androgenetic alopecia.

Role of vitamin D in hair loss: A short review

BACKGROUND

Vitamin D, a vitamin and hormone, plays an important role in dermatology and dermatotherapeutics, due to its anti-inflammatory and immunomodulatory properties, and regulation of keratinocyte differentiation and proliferation. It also affects the hair cycle, and its role in hair loss is under constant research.

OBJECTIVES

This review aims to give a brief overview of vitamin D biology within the hair follicle, role in the etiopathogenesis, and rationale for supplementation in various alopecias.

METHODS

A PubMed literature search was performed to review relevant current literature and studies investigating the role of vitamin D in the etiopathogenesis, as a supplement and a potential therapeutic modality in hair loss.

RESULTS AND CONCLUSION

Vitamin D is intricately involved in various signaling pathways of growth and differentiation of hair follicles. Most studies show an inverse relationship between serum vitamin D levels and non-scarring alopecias such as telogen effluvium, androgenetic alopecia, alopecia areata, and trichotillomania. Vitamin D deficiency is also associated with scarring alopecia. However, conclusive studies to demonstrate the benefit of vitamin D administration in correcting hair loss and managing these conditions are lacking. Hence, further studies are needed before vitamin D can be routinely recommended as a treatment modality in these conditions.