The Effect of Vitamin D Supplementation on Calcium Excretion in Thalassemia: a Dose Response Study

• Status: Unknown status
• Trial end date: 2014-12-01
• Target enrollment: 0
• Participant gender: All

Summary

The purpose of this pilot study is to determine the effect of various doses of vitamin D supplementation on vitamin D stores and calcium excretion in the urine in subjects with Thalassemia Major (TM). Subjects with TM are routinely placed on vitamin D supplements because they frequently have osteoporosis (a condition in which bone tissue thins and loses density and strength) and low vitamin D stores. The amount of vitamin D supplementation that is required to raise vitamin D stores in optimal levels is not known in TM, and will be determined in this study. Finally, a recent study in TM has linked blood vitamin D levels to urine calcium excretion, which is a risk factor for kidney stones. Therefore, we want to determine changes in calcium excretion with various vitamin D doses and with increasing vitamin D stores. We plan to test 3 doses of vitamin D for 3 months in children and adults with TM. Changes in vitamin D blood levels and urinary calcium will be determined. The results of this pilot study will be used in future studies that will examine the effect of various doses of vitamin D supplementation in the treatment of osteoporosis in TM.

• Phase: Phase 4
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Weill Medical College of Cornell University
• Treatments: Calcium, Dietary; Cholecalciferol; Ergocalciferols; Vitamin D; Vitamins

Criteria

Inclusion Criteria:

• Thalassemia Major (TM)

• 25 OHD: 15-29 ng/ml

• Age 6 to 60 years

• Albumin corrected serum Calcium: Normal (8.5-10.5 mg/dl)

Exclusion Criteria:

• Other thalassemia syndromes

• 25 OHD concentrations < 15 ng/ml or ≥30 ng/ml

• Subjects younger than 6 years

• Hypoparathyroidism

• Abnormal albumin corrected serum Ca (i.e. total calcium <8.5 or > 10.5 mg/dl)

• Medications that may adversely affect vitamin D metabolism (anticonvulsants) or absorption

• End stage renal, heart, or liver disease

• History of Nephrolithiasis or Nephrocalcinosis

• Diseases associated with hypercalciuria (ie. Sarcoidosis, Cushing syndrome, and Wilson disease to name a few)