They took 100 people with acne and tested their vitamin D levels, then compared them to 100 healthy people.

they took 100 people with acne and tested their vitamin D levels, then compared them to 100 healthy people.
the results?

Patients with acne had lower levles of vitamin D, higher levels of IL-6,and TNF-a which indicates higher inflammation.

then the 100 acne patients got vitamin D analog or placebo, this caused IL-6 and TNF-a levels to drop.
Vitamin D is a strong anti-inflammatory agent.