An effective oral vitamin D replacement therapy in persons with spinal cord injury

Background/objective: Vitamin D deficiency is prevalent in chronic spinal cord injury (SCI). A 3-month course of oral vitamin D ₃ to 'normalize' serum vitamin D levels was investigated. Design: Prospective drug-intervention study. Setting: VA Medical Center; private rehabilitation facility. Methods: Seven individuals with chronic SCI and vitamin D deficiency completed 3 months of oral vitamin D ₃ (i.e. cholecalciferol) supplementation. At screening, baseline, and months 1 and 3, blood was collected for serum calcium, 25 hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH), and N-telopeptide (NTx); 24-hour urine for calcium, creatinine, and NTx was performed. Oral vitamin D ₃ (2000 IU daily) and elemental calcium (1.3 g daily) were prescribed for 90 days. The results are expressed as mean ± standard deviation (SD). Analysis of variance with a Fisher's post-hoc analysis was performed to test for differences between study visits. Subjects were classified as deficient (<20 ng/ml), relatively deficient (20-30 ng/ml), or not deficient (>30 ng/ml) in 25(OH)D. Results: Serum 25(OH)D levels were greater at months 1 and 3 than at baseline (26 ± 6 and 48 ± 17 vs. 14 ±2 ng/ml; P = 0.005). Six of seven subjects were no longer deficient [25(OH)D >30 ng/ml] by month 3. Serum iPTH levels were significantly decreased at month 1 and month 3; serum NTx levels were significantly lower at month 3 than at baseline. Serum and urinary calcium levels remained within the normal range. Conclusion: A daily prescription of 2000 IU of oral vitamin D ₃ for 3 months safely raised serum 25(OH)D levels into the normal range in persons with chronic SCI on calcium supplementation.