Serum 25-hydroxy vitamin D levels in chronic fatigue syndrome: a retrospective survey.

Introduction: Patients with chronic fatigue syndrome (CFS) may be at risk of osteoporosis due to their relative lack of physical activity and excessive time spent indoors, leading to reduced vitamin D synthesis. We hypothesized that serum 25-OH vitamin D levels are lower in CFS patients than in the general British population.

Subjects And Methods: We performed a retrospective survey of serum 25-OH vitamin D levels in 221 CFS patients.