Although high rates of vitamin D insufficiency are encountered in SCI individuals, its consequences and the amount of vitamin D required to prevent insufficiency are still unknown, indicating a need for more intervention studies with well-defined outcome measures. Routine screening and monitoring of vitamin D as well as treatment of suboptimal status should be instituted in both acute and chronic setting. The close interactions between vitamin D and related bone minerals should be kept in mind when supplementing SCI individuals, and practices should be individualized with clinical conditions.

Study design: Prospective case series Objectives: To assess the effectiveness and safety of two vitamin D 3 repletion protocols given to individuals with spinal cord injury (SCI). Setting: Publicly-funded intensive inpatient rehabilitation center, Montreal, Canada. Methods: Thirty adults with recent SCI complete or incomplete sensorimotor impairments were recruited upon admission from designated regional SCI trauma centers. Participants with serum 25OHD ≤ 30 nmol/L were given 10,000 IU of weekly and 1000 IU of daily vitamin D 3 for 36.8 ± 11.9 days (higher dose: HD). Subjects with serum 25OHD > 30 nmol/L received 1000 IU of daily vitamin D 3 for 38.2 ± 11.6 days (lower dose: LD). Outcomes were changes in 25OHD levels from baseline to the end of the study period and safety outcomes. Thresholds for vitamin D deficiency, insufficiency and sufficiency were: 25OHD levels ≤30 nmol/L, 30-74 nmol/L, and ≥75 nmol/L. Results: At baseline, 34 and 66% of participants had serum 25OHD < 30 and >30 nmol/L. Both protocols induced a rise in serum 25OHD with a greater increase in the HD vs. LD regimen (31.4 [95% CI: 16.7, 46.0] vs. 11.7 nmol/L [95% CI: 2.2, 21.2]). None of the participants given the HD remained vitamin D deficient, but only one achieved vitamin D sufficiency. Nearly all individuals on the LD regimen remained vitamin D insufficient with only two reaching vitamin D sufficiency. No adverse effects were observed over the course of the supplementation. Conclusions: Although 1000 IU of daily vitamin D 3 alone or in combination with weekly 10,000 IU for an average of 37.6 days increased serum 25OHD, they were unsuccessful in improving the impaired vitamin D status during inpatient rehabilitation of individuals with a recent SCI.