Diminished and erratic absorption of ergocalciferol in adult cystic fibrosis patients.

Abstract

BACKGROUND:

Osteoporosis diminishes the quality of life in adults with cystic fibrosis (CF). Vitamin D deficiency resulting from malabsorption may be a factor in the etiology of low bone mineral density (BMD) in patients with CF.

OBJECTIVE:

Absorption of oral ergocalciferol (vitamin D2) and the consequent response of 25-hydroxyvitamin D in 10 adults with CF and exocrine pancreatic insufficiency was compared with that of 10 healthy control subjects.

DESIGN:

In this pharmacokinetic study, CF patients and control subjects were pair-matched on age, sex, and race. Each subject consumed 2500 microg oral vitamin D2 with a meal. The CF group also took pancreatic enzymes that provided > or = 80000 U lipase. Blood samples were obtained at baseline and at 5, 10, 24, 30, and 36 h after vitamin D2 consumption to measure serum vitamin D2 and 25-hydroxyvitamin D concentrations.

RESULTS:

Vitamin D2 concentrations in all subjects were near zero at baseline. CF patients absorbed less than one-half the amount of oral vitamin D2 that was absorbed by control subjects (P < 0.001). Absorption by the CF patients varied greatly; 2 patients absorbed virtually no vitamin D2. The rise in 25-hydroxyvitamin D in response to vitamin D2 absorption was significantly lower over time in the CF group than in the control group (P = 0.0012).

CONCLUSIONS:

Vitamin D2 absorption was significantly lower in CF patients than in control subjects. These results may help explain the etiology of vitamin D deficiency in CF patients, which may contribute to their low BMD.

• Authors: R K Lark, G E Lester, D A Ontjes, A D Blackwood, B W Hollis, M M Hensler, R M Aris
• Journal: The American journal of clinical nutrition (Am J Clin Nutr) Vol. 73 Issue 3 Pg. 602-6 (Mar 2001) ISSN: 0002-9165 [Print] United States
• PMID: 11237938 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Ergocalciferols
• Vitamin D
• 25-hydroxyvitamin D
• Lipase

Topics

• Administration, Oral
• Adolescent
• Adult
• Area Under Curve
• Bone Density
• Case-Control Studies
• Cystic Fibrosis (complications, metabolism)
• Ergocalciferols (administration & dosage, blood, pharmacokinetics)
• Exocrine Pancreatic Insufficiency (blood, complications)
• Female
• Humans
• Intestinal Absorption (drug effects)
• Lipase (administration & dosage, metabolism)
• Male
• Middle Aged
• Osteoporosis (etiology)
• Vitamin D (analogs & derivatives, blood)
• Vitamin D Deficiency (blood)