Effectiveness of two vitamin D3 repletion protocols on the vitamin D status of adults with a recent spinal cord injury undergoing inpatient rehabilitation: a prospective case series

Study design Prospective case series. Objectives To assess the effectiveness and safety of two vitamin D3 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 D3 for 36.8 ± 11.9 days (higher dose: HD). Subjects with serum 25OHD > 30 nmol/L received 1000 IU of daily vitamin D3 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 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 D3 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.