Magnesium (Mg)

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

  • Using medicines that contain magnesium. This includes many antacids, laxatives (such as milk of magnesia or Epsom salts), and magnesium supplements.
  • Medicine. Some antibiotics, insulin, and long-term use of diuretics can lower magnesium levels.
  • Recent intravenous (IV) fluids, such as fluids given during surgery.
  • Pregnancy. Magnesium blood levels may normally be low in the second and third trimesters of pregnancy.

Go to previous section Go to previous sectionGo to top of page Go to top of pageGo to next section Go to next section

Author: Maria G. Essig, MS, ELS Last Updated: April 17, 2008
Medical Review: Kathleen Romito, MD - Family Medicine
Brian D. O'Brien, MD - Internal Medicine

© 1995-2009 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

Click here to learn about Healthwise

Topic Contents
 Test Overview
 Why It Is Done
 How To Prepare
 How It Is Done
 How It Feels
 Risks
 Results
Arrow PointerWhat Affects the Test
 What To Think About
 References
 Credits