Effective Intramuscular Vitamin D2 in Patients with Systemic Sclerosis Non-Responding to Oral Supplementation; A Retrospective Observational Case Series

Objective: To assess the response to intramuscular vitamin D in patients not respond-ing to oral supplementation. Methods: A retrospective series included patients, with systemic sclerosis and a history of subclinical poor vitamin D status that was resistant to at least 6 months of oral supplementation, to whom intramuscular vitamin D2 was administered. Results: Twelve patients were identified, with a mean age of 47.8 years. All were women. Five had diffuse systemic sclerosis and seven had localized systemic sclerosis. The mean duration of the disease was 17.9 years, with a mean modified Rod-nan skin score of 14.9. All patients were twice injected, at a 15-day interval, 300,000 IU of ergocalciferol into the anterior gluteus muscle. The mean serum level of 25(OH)D increased from 12.9 ng/mL before the first injection, to 23 ng/mL two weeks after the first injection, and 37.1 ng/mL four weeks after the second injection (p<0.001). No side effects were observed. Conclusion: It is the first report of safely normalizing vitamin D levels with intramuscular ergocalciferol in patients with systemic sclerosis.