International Journal of Trichology

ORIGINAL ARTICLE
Year
: 2022  |  Volume : 14  |  Issue : 5  |  Page : 175--177

Vitamin D levels in alopecia areata and other alopecias: A retrospective case–control study at a single institution


Patrick Thanh Tran1, Alessandra Chen2, Lynn Yi3, Carolyn Goh4,  
1 Division of Dermatology at Harbor-UCLA Medical Center, Los Angeles, USA
2 Department of Dermatology at University of Southern California Keck School of Medicine, Los Angeles, USA
3 Department of Psychiatry, Stanford University, Stanford, CA, USA
4 Department of Medicine, Division of Dermatology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, USA

Correspondence Address:
Carolyn Goh
200 UCLA, Medical Plaza Driveway Suite 450 and 465, Los Angeles, CA 90095
USA

Abstract

Recent research has associated alopecia areata (AA), an autoimmune disorder, with deficiency of Vitamin D, which regulates immune processes. This retrospective study compared Vitamin D levels in AA patients to those of other alopecia diagnoses and nonalopecia controls. When compared to controls, patients with AA or other alopecia diagnoses did not demonstrate lower Vitamin D levels. However, when compared to other alopecia diagnoses, AA patients had a statistically significantly higher proportion of patients with Vitamin D deficiency and a lower mean Vitamin D level. Our findings suggest a greater association between lower Vitamin D levels and AA compared to other alopecia diagnoses. Further prospective studies investigating Vitamin D levels and supplementation in AA patients are needed to further elucidate this association and its potential relevance.



How to cite this article:
Tran PT, Chen A, Yi L, Goh C. Vitamin D levels in alopecia areata and other alopecias: A retrospective case–control study at a single institution.Int J Trichol 2022;14:175-177


How to cite this URL:
Tran PT, Chen A, Yi L, Goh C. Vitamin D levels in alopecia areata and other alopecias: A retrospective case–control study at a single institution. Int J Trichol [serial online] 2022 [cited 2023 Feb 7 ];14:175-177
Available from: https://www.ijtrichology.com/text.asp?2022/14/5/175/358100


Full Text



 Introduction



Recent research has associated alopecia areata (AA), an autoimmune disorder, with deficiency of Vitamin D, which regulates immune processes.[1] This study compares Vitamin D levels in AA patients to those of other alopecia diagnoses and nonalopecia controls.

 Methods



Data for 4883 alopecia patients and 4945 controls were obtained from the University of California, Los Angeles Health System (2013–2017). The alopecia group was selected by ICD codes for alopecia, and controls were age-, gender-, and race-matched patients. The dataset was further filtered for patients with documented serum 25-hydroxyvitamin D (25[OH] D) levels and no active Vitamin D prescriptions.

To test for statistical significance, two-tailed t-tests were performed. To control for confounders, a multivariate linear model using sex, race, age, and case–control status as the independent variables and Vitamin D level as the dependent variable was used. Statistical analysis was performed in the R Statistical Computing Environment (R Core Team; Vienna, Austria).

 Results



[Table 1] contains demographic data; [Table 2] includes 25(OH) D levels, deficiency, and prescription status. The mean (25(OH) D) levels for AA (28.7 ± 12.1) and all other alopecia diagnoses (30.4 ± 11.9) were higher than that of controls (25.8 ± 10.9), both with P < 0.001. In addition, the mean 25(OH) D level for AA was lower and the proportion of AA patients with Vitamin D deficiency (25[OH] D <20) was greater (29.6% vs. 27.1%) than that of other alopecias, with P = 0.068 and P < 0.001, respectively.{Table 1}{Table 2}

In addressing confounders, age showed a positive correlation with 25(OH) D levels (Pearson's correlation of 0.17), women had higher levels of 25(OH) D than men (30.2 ± 11.7 vs. 28.3 ± 10.2), Caucasian patients had the highest 25(OH) D levels (31.2 ± 11.1), and 25(OH) D levels were lowest in winter (26.8 ± 11.4). After adjusting for age, sex, race, and season, the prior relationships remained.

 Discussion



This study found that patients with AA or other alopecia diagnoses did not demonstrate 25(OH) D levels lower than controls. However, AA patients had a statistically significantly higher proportion of patients with Vitamin D deficiency when compared to other alopecias and a lower mean 25(OH) D level, which trended toward statistical significance. These findings suggest that Vitamin D may be more important in the pathogenesis of AA given its autoimmune nature.

In addition, lower 25(OH) D levels in controls do not preclude an association between Vitamin D and AA. Several studies have shown no difference in 25(OH) D levels between healthy controls and AA but still demonstrated the significance of lower 25(OH) D levels in the severity of AA.[2],[3]

Our study occurred at one institution in Southern California, where our population is less likely to be Vitamin D deficient and may consequently limit our statistical power.[4] Moreover, patients at our tertiary care center likely had comorbidities affecting Vitamin D levels (e.g., multiple sclerosis, lupus) not accounted for in our analysis.

Our findings suggest a greater association between lower Vitamin D levels and AA compared to other alopecia diagnoses. Further prospective studies investigating Vitamin D levels and supplementation in AA patients are needed to further elucidate this association and its potential relevance.

Financial support and sponsorship

This research was supported by NIH National Center for Advancing Translational Science (NCATS) UCLA CTSI Grant Number UL1TR001881 and by a grant from the UCLA Dermatology Research Foundation.

Conflicts of interest

There are no conflicts of interest.

References

1Kechichian E, Ezzedine K. Vitamin D and the skin: An update for dermatologists. Am J Clin Dermatol 2018;19:223-35.
2Erpolat S, Sarifakioglu E, Ayyildiz A. 25-hydroxyvitamin D status in patients with alopecia areata. Postepy Dermatol Alergol 2017;34:248-52.
3Unal M, Gonulalan G. Serum Vitamin D level is related to disease severity in pediatric alopecia areata. J Cosmet Dermatol 2018;17:101-4.
4Looker AC, Johnson CL, Lacher DA, Pfeiffer CM, Schleicher RL, Sempos CT. Vitamin D status: United States, 2001-2006. NCHS Data Brief 2011;59:1-8.