El-Hamd MA, et al. - The experts sought to assess the serum levels of 25 hydroxy vitamin D in subjects having acne vulgaris before and after treatment with isotretinoin. They also evaluated the association of serum levels of 25 hydroxy vitamin D with the severity of acne vulgaris. Findings demonstrated a significant inverse association between level of 25 hydroxy vitamin D and severity of acne vulgaris before treatment. Also, isotretinoin treatment resulted in significant increase in serum levels of 25 hydroxy vitamin D. The findings suggest that vitamin D could play a potential role in pathogenesis of acne vulgaris or acne vulgaris may have a negative impact on vitamin D synthesis.