Cancer-Associated Muscle Atrophy and Weakness: An Investigation of Etiology

Inclusion Criteria: * Age 35-80 years * Diagnosis of metastatic cancer with cachexia (≥5% drop in body mass in less than 12 months), metastatic cancer without cachexia (\<5% drop in body mass in 12 months) or no history of cancer but similar in age and sex as other groups. Exclusion Criteria: * Current use of vitamin D analogs * Fasting plasma glucose ≥126 mg/dL * Renal failure (serum creatinine \> 1.5mg/dl) * Chronic active liver disease (Bilirubin \> 17mmol/L, AST\>144IU/L, or ALT\>165IU/L) * Contraindications to MRI (e.g., pacemaker, ferrous materials within body). * Active coronary artery disease or history of unstable macrovascular disease (unstable angina, myocardial infarction, stroke, and revascularization of coronary, peripheral or carotid artery within 3 months of recruitment) * Renal insufficiency/failure (serum creatinine \> 1.5mg/dl) * Oral warfarin group medications or history of blood clotting disorders. * People who have taken Bevacizumab * Platelet count \<100,000 per uL * Pregnancy or breastfeeding * Alcohol consumption greater than 2 glasses/day or other substance abuse * Untreated or uncontrolled thyroid disorders * Debilitating chronic disease (at the discretion of the investigators) * Previous injury/trauma/surgery to the region being measured without full recovery * Pain in the area to be assessed * Any medical condition affecting the ability to execute a maximal muscle contraction * The presence of infections, highly communicable diseases (AIDS, active tuberculosis, veneral disease, hepatitis) or metastatic bone disease that may interfere with safely executing maximal effort. * Significant neurological or musculoskeletal disorders or disease that may interfere with safely executing maximal contraction * Any congenital, developmental, or other bone disease or previous surgeries that may interfere with successful testing