Effect of vitamin D depletion on tibialis anterior or soleus /body weight ratio. On the day of euthanasia, tibialis anterior (TA) (A) and soleus (B) of control and depleted rats were removed and weighed. TA or soleus/body weight ratio was calculated for each rat (n = 7 for control group and n = 9 for depleted group). TA/body weight ratio decreased in vitamin D-depleted old rats compared to control rats, whereas soleus/body weight ratio remained stable. Data presented are means ± SEM; *p < 0.05.