Please select the eligibility criteria that correspond to the clinical trial below.
Title: The Effect of Oral Niacinamide on Plasma Phosphorus Levels in Peritoneal Dialysis Patients
Brief Summary: Hyperphosphatemia is common in the peritoneal dialysis population. Current strategies are insufficient to optimize phosphorus control. Animal studies have shown niacinamide, a form of vitamin B, to reduce phosphate uptake by the rat small intestine. Our trial investigates the use of niacinamide, in addition to standard phosphorus lowering strategies, to reduce plasma phosphorus levels in peritoneal dialysis patients versus placebo.


Options:
A: Inclusion Criteria:

* Men or women greater than 18 years of age.
* The subject has voluntarily signed and dated the most recent informed consent form approved by an Institutional Review Board (IRB).

Exclusion Criteria:

* Receiving hemodialysis.
* Receiving or has received an investigational product (or is currently using an investigational device) within 28 days prior to Visit 2.
* Evidence of active and clinically significant infection at Visit 2.
* Dental work within 48 hours prior to Visit 2.
B: Inclusion Criteria:

* Men and women 18 years of age or greater and able to comply with the study protocol.
* eGFR within appropriate target ranges (15-40 ml/min/m² for late stage CKD stage 3 stage 4, and eGFR \> 60 ml/min/m² for normal subjects)
* Stable kidney function defined as an eGFR which remains within a 10ml/min range over a 3 to 6 month period prior to study enrollment. This will be determined from historical laboratory data.
* Willing to follow study protocol
* Have a level of understanding and willingness to cooperate with all visits and procedures as described by the study personnel
* Overall stable medical condition, defined as no malignancy, metabolic condition or gastrointestinal condition that would make it difficult to comply with the study protocol and complete both dietary study periods
* Able to read the consent form and provide informed consent.
* Serum calcium and phosphorus within the normal range off of vitamin D analogues, calcium supplements, and phosphate binders for 1 month.

Exclusion Criteria:

* 1. Age less than 18 years
* Are pregnant, plan on becoming pregnant during the study period, or breast-feeding, if female.
* Patient declines participation.
* GI malabsorption, short bowel syndrome, frequent vomiting, or gastroparesis.
* Subject receiving synthetic parathyroid hormone, glucocorticoids, calcitonin or bisphosphonates.
C: Inclusion Criteria:

* Age \> 18 years
* Capable of giving informed consent
* Duration of peritoneal dialysis \> 3 months
* Dose of phosphate binder(s) stable over previous 2 week period
* Plasma phosphours \> 4.9 mg/dL based on most recent laboratory data within 1 month of enrollment

Exclusion Criteria:

* Pregnancy
* Known liver disease
* Active peptic ulcer disease
* Treatment with carbamazepine
* Intolerance to niacinamide or niacin
* Current medication regimen including niacin or niacinamide \> 100 mg daily
* Planned or expected surgical procedure in the next 4 months
* Patients in nursing home or extended care facilities where administration of the study drug may not be appropriately given
D: Inclusion Criteria:

* Most recent phosphorus and mean phosphorus over last 3 months \> 5.5 mg/dL
* Age ≥ 18 years
* On chronic hemodialysis ≥ 6 months
* English speaking

Exclusion Criteria:

* Mentally incompetent
* AIDS
* Cancer
* Terminal illness
* Pregnancy
* Nursing home residence
* No telephone access
* In another phosphorus related study
* Unable to identify written words

Answer: C