Vitamina D en AA

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

• Yi Liu,
• Jing Li,
• Guirong Liang,
• Chaojiang Cheng,
• Yue Li &
• Xinfeng Wu 

Dermatology and Therapy volume 10, pages967–983(2020)Cite this article

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Abstract

Introduction

To investigate the associations of alopecia areata (AA) with serum vitamin D and calcium levels.

Methods

A systematic review of all relevant articles published up to February 2020 in PubMed, Embase, and Cochrane Library databases was conducted. Primary endpoints were serum 25-hydroxyvitamin D [25(OH)D] levels and vitamin D deficiency, and the secondary endpoint was serum calcium level. Odds ratio (OR) and standardized mean difference (SMD) with 95% CI across studies were analyzed.

Results

Data on 1585 patients with AA and 1114 controls from 16 case–control studies and three cross-sectional studies were included in this meta-analysis. A pooled meta-analysis was conducted using the random-effects model because of inter-study heterogeneity (vitamin D level, I² = 87.90%; vitamin D deficiency, I² = 81.10%; serum calcium level, I² = 83.80%). A combined analysis revealed that patients with AA had significantly lower mean serum 25(OH)D level compared with control (WMD − 9.08, 95% CI − 11.65, − 6.50, p < 0.001), and were more likely to have vitamin D deficiency (OR 4.14, 95% CI 2.34, 7.35, p < 0.001). However, the pooled analysis revealed that patients with AA did not have significantly lower serum calcium levels compared with control (WMD − 0.17, 95% CI − 0.40, 0.06, p = 0.143). Subgroup analysis suggested that matched control, mean age, and country might contribute to the heterogeneity of serum vitamin D level, while study design, matched control, and country might contribute to the heterogeneity of vitamin D deficiency.

Conclusion

Deficiency of serum 25(OH)D level, rather than calcium level, was present in patients with AA. Screening for vitamin D deficiency and vitamin D supplementation may be beneficial in the treatment of patients with AA.

Key Summary Points

Why carry out this study?

Alopecia areata (AA) is a form of non-scarring hair loss characterized by an autoimmune reaction to hair follicles with disordered, shortened hair cycle

Vitamin D deficiency was considered as a risk factor for the development of AA

The relationship between vitamin D deficiency and AA in patients was reported in two previous meta-analyses but not comprehensively evaluated because five subsequent studies were not considered

What was learned from the study?

Deficiency of serum 25(OH)D level, rather than calcium level, was present in patients with AA. Screening for vitamin D deficiency and vitamin D supplementation may be beneficial in treatment of patients with AA