Figure 1. Animal study protocol and Measurement of body weight, serum calcium, and serum 25(OH)D concentration of rats during the study period.
a. Animal study protocols and measurements of biomarkers b.Animals (N=7 per group) were fed with a diet containing either no vitamin D (-D), 2 IU/g vitamin D3 (+2D), or 6 IU/g vitamin D3 (+6D). Rats in three groups all gained body weight increase stably and no significant difference was observed among the 3 groups. c. No significant difference was observed among the 3 groups regarding serum calcium concentration. d. The serum 25(OH)D level varied significantly in each group in accordance with the vitamin D supplementation amount. Each points is the mean±SD of 7 animals. *p<0.05, **p<0.01.