Vitamin D in Treating Patients With Prostate Cancer

Study of Serum 25(OH) D3 Level Variability in Response to Different Doses of Oral Vitamin D Supplementation in Prostate Cancer Patients

RATIONALE: Vitamin D may be effective in treating patients with prostate cancer.

PURPOSE: This randomized phase II trial is studying how well 4 different doses of vitamin D works in treating patients with prostate cancer.

OBJECTIVES:

Primary

• To examine the pattern of response of serum 25(OH) D3 levels following cholecalciferol (vitamin D3) supplementation at four different oral doses in patients with prostate cancer.

Secondary

• To examine the pattern of response of parathormone (PTH) following vitamin D3 supplementation in these patients.
• To assess the toxicity of vitamin D3 supplementation in men with prostate cancer.

Tertiary

• To track occurrence of infections, deep vein thrombosis, vascular events, and falls in these patients.

OUTLINE: Patients are randomized to 1 of 4 treatment arms.

• Arm I: Patients receive 4,000 IU of oral cholecalciferol (vitamin D3) once daily.
• Arm II: Patients receive 6,000 IU of vitamin D3 once daily.
• Arm III: Patients receive 8,000 IU of vitamin D3 once daily.
• Arm IV: Patients receive 10,000 IU of vitamin D3 once daily. Treatment in all arms continues for 6 months in the absence of disease progression or unacceptable toxicity.

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate
• 25(OH) D3 level < 80 ng/mL

PATIENT CHARACTERISTICS:

Inclusion criteria:

• ECOG performance status 0-2
• Creatinine ≤ 2.0 mg/dL
• Corrected serum calcium ≤ 10.5 mg/dL

Exclusion criteria:

• History of malabsorption syndrome (e.g., pancreatic insufficiency, celiac disease, or tropical sprue)
• Hypersensitivity to cholecalciferol or one of its components

PRIOR CONCURRENT THERAPY:

• No other concurrent vitamin D supplementation