Vitamin D and Acne

Case-control studies consistently find vitamin D deficiency is more common and more severe in adults with nodulocystic and inflammatory acne than in matched controls. The mechanism is plausible — vitamin D modulates sebocyte biology, IL-17 and cathelicidin production, and Cutibacterium acnes-driven inflammation.

Deficiency prevalence in acne

A 2016 case-control study of Korean adults reported 25(OH)D was significantly lower in acne patients (mean ~15 ng/mL) than controls (~22 ng/mL), with an OR of 2.9 for deficiency (< 20 ng/mL) after adjustment. A 2020 meta-analysis pooling six studies confirmed the association, though heterogeneity was high.

Supplementation evidence

• A small 2016 double-blind RCT in Turkey (45 patients with nodulocystic acne and 25(OH)D < 20 ng/mL) reported cholecalciferol 1,000 IU/day for 8 weeks reduced inflammatory lesion count significantly more than placebo.
• Adjunctive vitamin D correction in patients on isotretinoin or oral antibiotics is a common dermatology recommendation, though large trials are lacking.
• Topical vitamin D analogues (calcipotriene) are effective for psoriasis but have not shown consistent benefit for acne.

What to do

1. Correct deficiency if present — cholecalciferol 1,000–2,000 IU/day for 8–12 weeks in mild-moderate deficiency.
2. Don't expect vitamin D alone to clear moderate-to-severe acne — it's an adjunct to dermatologic therapy.
3. Sun exposure has mixed effects on acne — some people flare, some improve. Follow your own experience.