Intramuscular Vitamin D2 in Patients With Systemic Sclerosis Not Responding to Oral Supplementation: A Retrospective Observational Case Series

BackgroundThis study aimed to evaluate changes in serum 25-hydroxyvitamin D (25(OH)D) levels following intramuscular (IM) ergocalciferol in patients with systemic sclerosis (SSc) and persistently low levels (<30 ng/mL) despite at least six months of oral cholecalciferol supplementation.Clinical outcomes of SSc were not assessed. MethodologyThis retrospective series included patients with SSc who received IM vitamin D2 after non-response to oral supplementation.Non-response was defined as a serum 25(OH)D level remaining below 30 ng/mL after at least six months of oral cholecalciferol at a dose of 10,000 IU weekly.Serum 25(OH)D was measured before the first injection, two weeks after the first injection, and four weeks after the second injection. ResultsIn total, 12 patients were identified, with a mean age of 47.8 years; all were women.Five patients had diffuse cutaneous SSc, while seven had limited cutaneous SSc.The mean disease duration was 17.9 years, with a mean modified Rodnan skin score of 14.9.All patients received two injections of 300,000 IU of ergocalciferol into the anterior gluteus muscle at a 15-day interval.The mean serum 25(OH)D level rose from 12.9 ng/mL before the first injection to 23.1 ng/mL two weeks after the first injection, and to 37.2 ng/mL four weeks after the second injection (p < 0.001).Overall, 10 of the 12 patients reached a level of 30 ng/mL or higher.No adverse events were reported during the follow-up period. ConclusionsIn this small retrospective series, IM ergocalciferol increased serum 25(OH)D levels and was not associated with reported adverse events.Prospective controlled studies are needed to confirm these findings.