0

The full content of Annals is available to subscribers

Subscribe/Learn More  >
Articles |

Omeprazole Therapy Causes Malabsorption of Cyanocobalamin (Vitamin B12)

Stefan P. Marcuard, MD; Lisa Albernaz, RN; and Prabhaker G. Khazanie, PhD
[+] Article and Author Information

From East Carolina University School of Medicine, Greenville, North Carolina. Request for Reprints: Stefan P. Marcuard, MD, Section of Gastroenterology, Department of Medicine, East Carolina University School of Medicine, Greenville, NC 287858-4354. Acknowledgments: The authors thank the Human Health Division of Merck, Inc. for its support; and the Department of Medicines, Text/Information Processing Center for preparation of the manuscript. Grant Support: In part by grant 585451 from the American College of Gastroenterology.


Copyright ©2004 by the American College of Physicians


Ann Intern Med. 1994;120(3):211-215. doi:10.7326/0003-4819-120-3-199402010-00006
Text Size: A A A

Objective: To evaluate protein-bound cyanocobalamin (vitamin B12) sub absorption before and after omeprazole (Prilosec) therapy in healthy male volunteers.

Design: Clinical trial in which each volunteer served as his own control.

Setting: Outpatient department of a university medical center.

Participants: Ten healthy, male volunteers 22 to 50 years old.

Intervention: Each participant had a modified Schilling test (protein-bound cyanocobalamin) and a gastric analysis, as well as measurements of serum vitamin B12, gastrin, and folate levels. Five patients were then randomly assigned to take either 20 mg or 40 mg of omeprazole daily. After 2 weeks of omeprazole therapy, these tests were repeated.

Measurements: The modified Schilling test, gastric analysis, serum gastrin level, folate level, and cyanocobalamin level.

Results: At the end of the 2-week treatment period, cyanocobalamin absorption decreased from 3.2% to 0.9% (P = 0.031) in participants receiving 20 mg of omeprazole daily. In patients taking 40 mg of omeprazole daily, cyanocobalamin absorption decreased from 3.4% to 0.4% (P < 0.05).

Conclusions: Omeprazole therapy acutely decreased cyanocobalamin absorption in a dose-dependent manner.

Figures

Grahic Jump Location
Figure 1.
Basal acid output and maximal acid output before and after 2 weeks of omeprazole therapy.P

Means ±SE are shown. *  < 0.01.

Grahic Jump Location
Grahic Jump Location
Figure 2.
The modified Schilling test (for protein-bound cyanocobalamin) before and after 2 weeks of omeprazole therapy.1212

B = vitamin B (cyanocobalamin).

Grahic Jump Location
Grahic Jump Location
Figure 3.
Schilling test results before and after 2 weeks of omeprazole therapy.P1212

A statistical decrease ( = 0.031) occurred in cyanocobalamin absorption in both groups. Means ±SE are shown. B = vitamin B (cyanocobalamin).

Grahic Jump Location
Grahic Jump Location
Figure 4.
Mean serum gastrin levels before and after 2 weeks of omeprazole therapy.PP

Increases in gastrin levels occurred in both the 20-mg and 40-mg omeprazole groups ( = 0.06 and < 0.01, respectively). Means ±SE are shown.

Grahic Jump Location
Grahic Jump Location
Figure 5.
Serum cyanocobalamin levels before and after 2 weeks of omeprazole therapy.1212

No statistical differences were found in either group. Means ±SE are shown. B = vitamin B (cyanocobalamin).

Grahic Jump Location

Tables

References

Letters

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Comments

Submit a Comment
Submit a Comment

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.

Toolkit

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Advertisement
Related Articles
Related Point of Care
Topic Collections
PubMed Articles

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)