Taking a nutritional supplement containing vitamin D could help people with a common skin problem, researchers say.

Atopic dermatitis, the most common form of eczema, affects around 15 million Americans, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Symptoms include itching, redness, swelling, cracking and scaling.

It had previously been found that a deficiency in a peptide called cathelicidin correlated with worsened cases of atopic dermatitis.

In an attempt to devise a treatment, researchers at the University of California-San Diego School of Medicine gave study participants vitamin D3 supplements every day for three weeks.

They found that the vitamin appeared to correct the subjects’ cathelicidin deficiency – and even boosted production in those without atopic dermatitis.

“These results suggest that supplementation with oral vitamin D dramatically induces cathelicidin production in the skin of patients with atopic dermatitis,” commented researcher Dr. Tissa R. Hata.

Separate research has also linked vitamin D3 nutritional supplements to a reduced risk of osteoporosis, as well as overall bone health, dental health and elevated mood.