Failure of high-dose ergocalciferol to correct vitamin D deficiency in adults with cystic fibrosis.

Abstract

RATIONALE:

Treatment guidelines for vitamin D monitoring and supplementation in cystic fibrosis (CF) have recently been developed and published by a consensus committee, but have not been prospectively tested.

OBJECTIVES:

To use these guidelines to determine the percentage of adults with CF requiring vitamin D repletion therapy and to evaluate the effectiveness of the currently recommended high-dose oral ergocalciferol repletion protocol.

METHODS:

Prospective study of clinical outcomes after therapy with the recommended vitamin D repletion algorithm.

RESULTS:

Of 134 adults with CF, 109 (81.3%) were found to have 25-hydroxyvitamin D (25-OHD) levels below the recommended 30 ng/ml. Sixty-six of these adults completed the recommended course of 400,000 IU of oral ergocalciferol over 2 months, and only five (8%) responded with correction of their serum 25-OHD to the goal of 30 ng/ml or greater (mean change, +0.3 ng/ml; from 18.8 to 19.1 ng/ml). In the 33 adults with CF who also completed the recommended second course of 800,000 IU of ergocalciferol over 2 months, none demonstrated correction of their deficiency (mean change, -1.2 ng/ml).

CONCLUSION:

The results of this study demonstrate that a majority of adults with CF have serum 25-OHD levels below 30 ng/ml, and the currently recommended ergocalciferol repletion regimen often does not fully correct vitamin D deficiency and may need to be revised to include even higher dosing of ergocalciferol. Further work is needed to establish the ideal 25-OHD level for maximizing calcium absorption and bone health in CF.

• Authors: Michael P Boyle, Michelle L Noschese, Sharon L Watts, Marsha E Davis, Shane E Stenner, Noah Lechtzin
• Journal: American journal of respiratory and critical care medicine (Am J Respir Crit Care Med) Vol. 172 Issue 2 Pg. 212-7 (Jul 15 2005) ISSN: 1073-449X [Print] United States
• PMID: 15860755 (Publication Type: Clinical Trial, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Ergocalciferols
• Vitamin D
• 25-hydroxyvitamin D

Topics

• Adult
• Cystic Fibrosis (complications)
• Dose-Response Relationship, Drug
• Ergocalciferols (administration & dosage, therapeutic use)
• Female
• Humans
• Male
• Middle Aged
• Retreatment
• Seasons
• Treatment Failure
• Vitamin D (analogs & derivatives, blood)
• Vitamin D Deficiency (blood, drug therapy, etiology)