Serum Levels of 25-Hydroxyvitamin D in Patients with Seborrheic Dermatitis: A Case-Control Study

Rahimi S

Published in Dermatology Research and Practice

Methodology

Case-control study comparing serum 25-hydroxyvitamin D concentrations between patients with clinically diagnosed seborrheic dermatitis and age/sex-matched controls, with severity scoring.

Key Findings

In a case-control study of 289 participants, patients with seborrheic dermatitis had significantly lower mean serum 25(OH)D than controls, with vitamin D deficiency more prevalent in cases; severity scores showed a weak inverse correlation with vitamin D level.

Conclusions

Seborrheic dermatitis is associated with lower vitamin D levels, but this case-control design cannot show that deficiency causes the condition or that supplementation helps.

Limitations

Cross-sectional case-control design cannot establish causation or direction; single-centre hospital sample; seasonal and sun-exposure confounding not fully controlled; no supplementation arm to test whether repletion improves disease.