A derivative of activated vitamin D may help to manage hair loss caused by alopecia areata (AA), according to a new study.
AA is a condition in which the immune system mistakenly attacks hair follicles, resulting in the loss of clumps of hair, and occasionally, baldness. The disorder currently affects approximately 6.8 million people in the United States. Results from a pilot study have shown that a vitamin D derivative called calcipotriol may be an effective treatment for AA.

In the recent study, which was published in the journal Dermatologic Therapy, participants applied a 0.005 percent calcipotriol lotion twice daily for three months. Researchers measured hair regrowth after four, eight, and 12 weeks, finding that regrowth began to occur after an average of 4.2 weeks. Hair regrowth had begun in 59 percent of patients after 12 weeks of treatment.
“Topical calcipotriol can be an alternative treatment in AA and it could prove to be more useful in patients who are vitamin D deficient,” the authors said.

A previous study suggested that the severity of AA was linked to low vitamin D levels, while another found that the hair follicles of AA patients contained fewer vitamin D receptors than those of healthy controls.