Serum Levels of Thyroid Hormones and Vitamin D in Women with Melasma

Background and purpose: Melasma is a common skin pigmentation disorder that manifests as hyperpigmented macules and patches. Genetic predisposition, sun exposure, and pregnancy are known risk factors for melasma. Previous studies have suggested that thyroid disorders may be associated with melasma. Given the fact that vitamin D affects and stimulates the production of melanin by melanocytes, this study aimed to investigate the relationship between thyroid disorders and serum level of vitamin D with melasma in female patients attending Qaemshahr Razi Hospital and Sari Bouali-Sina Hospital. Materials and methods: In this study, 80 people were divided into melasma group (n=40) and control group (n=40). They were matched for sex and age. Serum levels of TSH, Anti-TPO, T3, T4, and Vit D were measured in both groups. The standard mMASI score was used to measure the clinical severity of pigmentation in patients with melasma. Results: The prevalence of thyroid abnormalities and serum levels of vitamin D were seen in 50% and 47.5% of patients with melasma and 27.5% and 40% of the control group, respectively. Examination of thyroid hormone and vitamin D levels showed that T3 level was significantly higher in case group (P<0.05). Investigating the relationship between thyroid hormones, vitamin D and age with mMASI Score showed a relationship only between Anti-TPO and mMASI Score (P< 0.05). Conclusion: Thyroid autoimmune disorders are associated with melasma and severity of pigmentation. Centrofacial form of melasma is also the most common clinical form.