Inclusion criteria:
Age ³ 18, CKD on hemodialysis, men and women, hemoglobin ³ 9g/dl, albumin ³ 3.0g/dl, no recent (in the last three months) admissions to the hospital, ability to walk ten feet with or without a walking aid.
Exclusion criteria:
Subjects who are pregnant or lactating; subjects with history of kidney stones, malabsorption syndromes, tertiary hyperparathyroidism defined by a parathyroid hormone of \>500pg/ml, current use of corticosteroids, non-ambulatory subjects (for example paraplegic subjects), serious fracture in the last three months, and corrected calcium levels of 10.5 mg/dl or greater.
