Micronutrient levels and thyroid functions in scarring alopecias: Do they play a role in disease pathogenesis?

Scarring alopecias are chronic inflammatory disorders characterised by irreversible hair follicle destruction. In this study, we aimed to evaluate the potential roles of serum ferritin, folate, vitamin B12, vitamin D levels and thyroid function markers in the pathogenesis of scarring alopecias. Between 2020 and 2025, a total of 68 patients over the age of 18 who were diagnosed with scarring alopecia based on clinical and/or histopathological findings and whose medical records were accessible retrospectively were included in the study, along with 68 healthy control subjects. Serum levels of ferritin, folate, vitamin B12, vitamin D, and thyroid function markers were recorded and statistically compared between groups. Among patients with scarring alopecia, 91.2% were female (n = 62), with a mean age of 47.25 ± 12.98 years. The average disease duration was 34.37 ± 24.22 months (min: 3, max: 144). The distribution of diagnoses among patients was as follows; lichen planopilaris in 45.6% (n = 21), frontal fibrosing alopecia in 29.4% (n = 20), pseudopelade in 16.2% (n = 11), discoid lupus erythematosus in 7.4% (n = 5), and folliculitis decalvans in 1.5% (n = 1). There were no statistically significant differences between patients with scarring alopecia and the control group regarding serum vitamin B12 (340.19 ± 107.950 vs. 357.04 ± 107.549 ng/L, p = 0.373), folate (11.89 ± 6.11 vs. 12.23 ± 6.53 ng/mL, p = 0.767), ferritin (34.75 ± 38.05 vs. 39.89 ± 66.74 µg/L, p = 0.593), and vitamin D (54.3 ± 26.57 vs. 58.59 ± 37.38 nmol/L, p = 0.434) levels. Thyroid function tests (TSH and free T4) were also similar between the two groups (p > 0.05). Our study demonstrated that serum ferritin, folate, vitamin B12, vitamin D levels and thyroid function in patients with scarring alopecia were similar to those in the healthy control group.