Vitamin D Supplementation and Bone Health in Adults with Diabetic Nephropathy: Preliminary Findings from a Randomized Controlled Trial

Abstract

Vitamin D (vitD) is a nutrient of concern in Canada particularly for those with diabetes and chronic kidney disease (CKD). Participants (18-80y) with diabetes and CKD were randomized to receive either 50mcg/day (n=33) or 1,000mcg/month (n=30) vitD3 for 6-months. Variables studied included: anthropometric/demographic data, routine clinical blood work, serum/plasma 25(OH)D, 1,25(OH)2D, PTH, bone turnover markers (BTM), and vitD intake. No significant differences in clinical characteristics between groups or study visits were observed (p>0.05). Adherence to daily and monthly supplementation was 93% and 100%, respectively. Mean 25(OH)D and 1,25(OH)2D concentrations increased in both groups after 6-months; but significant increases in 25(OH)D were seen only in the daily group (78.4 to 95.1nmol/L; p=0.01). There were no significant differences between groups over 6-months in PTH or BTM (p>0.05). This suggests that both once daily and once monthly vitD supplementation strategies are equally effective at influencing vitD status despite differences in adherence.