Inclusion Criteria - Groups 1 Cancer Cachexia & 2 Cancer NO Cachexia:

• Adults 21 years or older.
• BMI < 45.
• Diagnosis of metastatic cancer or localized tumors with cachexia (≥ 5% drop in body mass in less than 12 months), metastatic cancer or localized tumors 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/dlmen, > 1.3mg/dl women).
• Oral warfarin group medications or history of blood clotting disorders.
• People who have taken Bevacizumab less than 30 days prior to study muscle biopsy, and scheduled to have another dose of Bevacizumab within 30 days of the muscle biopsy.
• Platelet count <100,000 per uL within the last 7 days.
• Pregnancy or breastfeeding.
• Alcohol consumption greater than 2 glasses/day or other substance abuse.
• Untreated or uncontrolled thyroid disorders (TSH range of 0.5 to 10 mlU/L).
• 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 (DXA T Score <-3).
• The presence of infections, highly communicable diseases (AIDS, active tuberculosis, venereal 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.

Inclusion Criteria - Group 3 NO Cancer:

• Adults 21 years or older.
• BMI < 45.

Exclusion Criteria:

• Diagnosis of Rheumatoid Arthritis.
• Current use of corticosteroids.
• Diagnosis of COPD: Chronic Obstructive Pulmonary Disease.
• Patient is taking calcium or vitamin D supplements and unwilling to stop for study duration.
• Calcium or phosphorus level above the institutional upper limit of normal.
• Fasting plasma glucose ≥ 126 mg/dL.
• Renal failure (serum creatinine > 1.5mg/dl men, > 1.3mg/dl women).
• Chronic active liver disease (Total Bilirubin > 1.2mg/dl, AST> 1.5IU/L, or ALT>1.5IU/L).
• History of chronic hepatitis.
• 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).
• Oral warfarin group medications or history of blood clotting disorders.
• People who have taken Bevacizumab in the last 6 weeks.
• Platelet count <100,000 per uL within the last 7 days.
• Pregnancy or breastfeeding.
• Alcohol consumption greater than 2 glasses/day or other substance abuse.
• Untreated or uncontrolled thyroid disorders (TSH > 10 or <. 5mlU/L).
• 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 ( DXA T Score < - 3).
• The presence of infections, highly communicable diseases (AIDS, active tuberculosis, venereal 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.