Vitamin D 3 regulation of body fat, cytokines, and calpain gene expression

BACKGROUND: We conducted an in vivo experiment to determine whether vitamin D 3 acts as a fat synthesizer and/or meat tenderizer in mice. At 6 weeks of age, 20 male C57BL/6 wild‐type mice were randomly divided into two groups (10 mice per group) and fed a modified AIN93G diet with (vitamin D 3 diet) or without (basal diet) 10 IU 25‐OH‐cholecalciferol kg −3 for 3 weeks. RESULTS: When vitamin D 3 was fed to mice for 3 weeks, body fat was significantly increased compared to mice fed a basal diet. There was, however, no difference in body weight between the two groups. Vitamin D 3 increased the gene expressions of pro‐inflammatory cytokines and peroxisome proliferator‐activated receptor gamma, but decreased interleukin‐15 in adipose tissue through nuclear vitamin D receptor and uncoupling protein‐2 signals. The muscle inducible nitrate oxide synthase content of mice fed vitamin D 3 was higher than those fed a basal diet, while muscle arginase l showed a reverse phenomenon. longissimuss dorsi muscle of vitamin D 3 ‐fed mice showed more severe fat deposition than those fed a basal diet. Vitamin D 3 amplified muscle u‐ and m‐calpain protein content and suppressed muscle calpastatin protein content. CONCLUSION: These findings suggest that vitamin D 3 can be used as a fat synthesizer and meat tenderizer in meat‐producing animals. Copyright © 2011 Society of Chemical Industry