Please select the eligibility criteria that correspond to the clinical trial below.
Title: Calcium and Phosphorus Balance and Calcium Kinetics in Patients With Stage 3/4 Chronic Kidney Disease
Brief Summary: The purpose of this study is to gain a better understanding of calcium absorption and metabolism in patients with Chronic Kidney Disease (CKD) using calcium balance and kinetic methods.


Options:
A: Inclusion Criteria:

* Chronic kidney disease patients aged 18 to 80 years
* Chronic kidney disease stage 3 (defined as a glomerular filtration rate of 30-60 ml/min/1.73m2)
* Office blood pressure controlled to less than 140/90 mmHg for 12 months before entry into the study
* Total cholesterol less than 5.5 mmol/l

Exclusion Criteria:

* Existing or previous treatment within 1 year with a phosphate binder or vitamin D analogue
* Uncontrolled hyperphosphataemia (serum phosphate \>1.8 mmol/l)
* Uncontrolled secondary hyperparathyroidism (PTH \>80 pg/ml)
* Diabetes mellitus
* Pregnancy
* Moderate-severe cardiac valvular disease
B: Inclusion Criteria:

* Eligible subjects will be male or female patients with end-stage renal disease on maintenance hemodialysis for less than 5 years, with elevated LDL cholesterol
* Currently treated with oral phosphate binders
* Coronary artery calcium scores of 30 to 5000 Agatston units measured by electron beam CT scanning
* Written informed consent
* Negative serum pregnancy test if appropriate
* Expect to comply with protocol procedures and schedule

Exclusion Criteria:

* Unstable angina pectoris
* Severe congestive heart failure
* Severe obstructive pulmonary disease requiring supplemental oxygen
* Severe liver dysfunction
* Severe malnutrition
* Severe hyperparathyroidism
* Known HIV
* Active malignancy for which the subject is receiving chemotherapy or radiation
* Planned renal transplant within the next year
* Clinical evidence of calciphylaxis or recent history of hypercalcemia
* History of obstructed bowels
* Hypersensitivity to any of the components of the study medication
* History of swallowing disorders
* Weight \> 300 pounds
* Any condition which makes patient participation not in the patient's best interest
C: Inclusion Criteria:

1. Patients with a GFR of \< 45 ml/min;
2. Intact serum PTH \> 37 pg/ml;
3. Age \> 35 years (both genders and all races);
4. Able to perform two three-week balance studies;
5. Not on oral calcium or vitamin D other than multi vitamin, or willing to stop calcium or vitamin D for one month prior to entry in the study (day 1 of first calcium balance period);
6. Female patients must be post-menopausal (defined as last menstrual period at least 12 months prior to screening visit) or surgically sterile by hysterectomy;
7. On stable doses of diuretics, bisphosphonates, anti-epileptics (except dilantin) for at least 2 months.

Exclusion Criteria:

1. Serious underlying systemic disease (including uncontrolled diabetes, lupus, hypertension, amyloid, etc);
2. Taking drugs that alter calcium and phosphate balance or homeostasis including high dose cholecalciferol or ergocalciferol (1000 U/day or 50,000U/ wk, respectively), active vitamin D metabolites, calcimimetics, PTH analogues in the last 30 days;
3. Taking drugs that the investigator feels will alter calcium balance;
4. Plan to initiate dialysis in the next six months;
5. Hypercalcemia defined as serum calcium \> 10.5 mg/dl;
6. Hyperphosphatemia defined as serum phosphate \>5.5mg/ml;
7. Intestinal disease that alters absorption or normal intestinal function including celiac disease, small bowel resection, bariatric surgery;
8. Smoking
D: Inclusion Criteria:

* Under a physician's care for CKD for \> 2 months and are not expected to begin dialysis for 4 months
* Screening estimated GFR of 15-59 mL/1.73 m2
* Serum phosphorus \>= 4.7 mg/d following washout

Exclusion Criteria:

* Requiring treatment with cinacalcet HCI or compounds containing phosphate, aluminum, calcium or magnesium
* Rapidly progressing glomerulonephritis
* Cirrhosis or other clinically significant liver diseases
* Past or present uncontrolled peptic ulcer, Crohn's disease, malignancy or recent GI bleed

Answer: C