1,25(OH)2D deficiency leads to sarcopenia. (A) Body weight, (B) weight of tibialis anterior (TA) muscle and gastrocnemius (Gas) muscle, (C) muscle weight/body weight ratio, and (D) grip strength in 3- and 6-month-old WT and Cyp27b1 KO male mice. Values are means ± SEM of 6 determinations per group. *P<0.05; **P<0.01; ***P<0.001, compared with WT mice. #P<0.05; ##P<0.01, compared with 3-month-old genotype matched mice.