Association of Alopecia Areata with Vitamin D and Calcium Levels: A Systematic Review and Meta-analysis

Alopecia areata: What's new in the epidemiology, comorbidities, and pathogenesis?

BACKGROUND

Alopecia areata (AA) is a common, acquired, and nonscarring type of hair loss that affects people of every generation and is intractable in severe and relapsing cases. Patients with AA, especially those with greater scalp involvement, have poor health-related quality-of-life scores.

PURPOSE

Following our previous review article in the April 2017 issue of the Journal of Dermatological Science, we aim to provide a pair of review articles on recent progress in multidisciplinary approaches to AA.

MAIN FINDINGS

We found more than 1800 publications on AA from July 2016 to December 2022.

CONCLUSIONS

In this review, we focused on the latest information on the epidemiology, comorbidities, and pathogenesis of AA.

Vitamin D supplementation for patients with alopecia areata: A protocol for systematic review and meta-analysis

BACKGROUND

Several studies have reported an association between low Vitamin D (VD) levels and Alopecia areata (AA), and suggested VD preparations as a potential therapy. VD has immunomodulatory function closely associated with a variety of skin diseases, but there is no conclusive evidence to support VD supplementation for patients with AA. Therefore, we will conduct a meta-analysis to collect and evaluate the efficacy and safety of VD supplementation in the treatment of AA.

METHODS

We will search the following databases according to the developed strategy: Cochrane Library, PubMed, Web of Science, EMBASE, Scopus, Google scholar for Randomized controlled trials related to VD supplementation for AA. The retrieval time is from the establishment of each database to July 2022. Two reviewers will independently complete the literature search and screening, risk of bias assessment and data extraction. Severity of Alopecia Tool, Alopecia Density and Extent, Lesional area and senstivity (score) will be the primary results. RevMan V.5.3 will be used for data analysis and synthesis. For dichotomous outcomes and the continuous outcomes, we will calculate risk ratio with 95% Confidence intervals and mean differences or standardized mean differences with 95% Confidence intervals respectively. The reporting bias will be investigated using funnel plots, and the asymmetry of the funnel plots will be explained using the Harbord modified test or the Egger's regression test.

RESULTS

The results of the study expect to provide a high-quality, evidence-based recommendation on VD supplementation in the treatment of AA for clinicians.

CONCLUSIONS

The study will provide scientific and useful evidence for better use of VD supplementation in treating AA.

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.