Vitamin D deficiency is unlikely to be implicated in the pathogenesis of frontal fibrosing alopecia (FFA), according to new Australian research.

A retrospective study compared vitamin D levels in 100 women with FFA and 100 women with female pattern baldness. Women taking vitamin D supplements were excluded.

The study, published as a Research Letter in JAAD International, said most women were vitamin D sufficient ≥50 nmol/L.

“The mean 25-hydroxy vitamin D level in women with FFA was 68.9 nmol/L (SD, 21.44 nmol/L) compared with 65.96 nmol/L (SD, 23.02 nmol/L) in women with female pattern hair loss.”

Vitamin D insufficiency was observed in 20% of patients from both groups. The majority 80-90% were mild (30-49 nmol/L), some were moderate (12.5-29 nmol/L) and none had severe vitamin D insufficiency.

“When analyzed for specific age brackets (<50, 50-59, and >60 years), the mean vitamin D levels observed were 65.38, 56.16, and 74.47 nmol/L in the FFA group, compared with 63.9, 57.2, and 75.83 nmol/L in the female pattern hair loss group.”

The study, from hair loss experts Sinclair Dermatology in Melbourne, said patients with nonscarring alopecia were historically thought to have consistently lower vitamin D concentrations than controls, justifying serum monitoring.

“Our findings suggest that there may be no additional requirement to measure vitamin D levels in patients with FFA compared to other forms of alopecia,” the investigators said.

“Given the similarity and status of vitamin D levels across our patients, vitamin D deficiency is unlikely to be implicated in the pathogenesis of FFA.”

“This finding neither supports nor disproves an association between the application of facial sunscreen and FFA,” they said.