Differential Effects of Ergocalciferol and Cholecalciferol Therapies in Chronic Kidney Disease

Vitamin D helps form and strengthens bones by allowing the body to absorb calcium. Vitamin D
helps the immune system fight infection as well as helps keep muscles strong. Without enough
vitamin D, bones can become weak, thin and brittle.

Vitamin D is useful in people with various types of health issues. Patients with CKD exhibit
an unusually high rate of vitamin D deficiency, which may contribute to some of the poor
clinical outcomes in this group.

This study will randomize patients with CKD and low vitamin D levels to two groups; one group
will be treated with vitamin D2 (ergocalciferol) and the other group will be treated with
vitamin D3 (cholecalciferol). The purpose of this study is to compare the effects of the two
different forms of vitamin D specifically in patients chronic kidney disease.

Inclusion Criteria:

- Age 18 and above

- Chronic kidney disease with an estimated glomerular filtration rate (GFR) between
15-60 ml/min (CKD stage III-IV)

- Vitamin D insufficiency (25-hydroxyvitamin D level < 30 ng/mL) that has not been
treated with vitamin D replacement since the acquisition of this level

Exclusion Criteria:

- Current treatment with cholestyramine

- Presence of GI disorders such as short bowel, history of gastrectomy, colectomy,
gastric bypass, inflammatory bowel disease, celiac disease, disorders of fat
absorption, chronic diarrhea.

- Liver cirrhosis

- Known current substance abuse

- Current treatment with immunosuppressant medications

- Presence of chronic infection

- History of chronic inflammatory disease (i.e. - lupus, active rheumatoid arthritis,
Crohns disease)

- Currently receiving high-dose vitamin D replacement (avg dose of ≥ 3,000 U per day) or
"active" vitamin D analogue (e.g., calcitriol, which is 1,25-dihydroxyvitamin vitamin
D).