This study is designed to gain a better understanding of the mechanisms leading to muscle wasting and metabolic abnormalities in skeletal muscle of cancer patients.

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

This study will recruit patients with metastatic cancer with or without evidence of cachexia, defined as ≥5% drop in body mass in less than 12 months. Controls without cancer but similar in age, sex, and body mass index will be recruited.