Young Female with Elevated Creatinine Who Takes Food Supplements

Author: Joshua Schwimmer, M.D., FACP, FASN

An otherwise healthy 35-year-old woman is found to have a serum creatinine of 2.5 mg/dL during routine lab work ordered by her PCP. An initial workup for renal insufficiency was negative.

Further questioning revealed that she was taking creatine supplements.

What is the most likely reason for increase in creatinine?
1. IgA nephropathy
2. Polycystic kidney disease
3. Creatine supplements
4. Urinary obstruction

Answer: (highlight the line below with the mouse to see the answer)
3. Creatine supplements

The supplements were stopped, and a repeat creatinine was 1.0 mg/dL (normal).

Creatine is converted into creatinine, which apparently explained the increased value. I was surprised that creatine supplements could lead to an increase in creatinine of this magnitude. I routinely ask about over the counter medications and supplements, but this experience suggests that patients with otherwise unexplained elevation in serumcreatinine should be asked specifically about creatine supplementation.

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Published: 11/01/2006


  1. What was the dose of creatine in the supplements? There are no details regarding how often and how much she was taking.

  2. which are the foodstuffs having high creatin contents

  3. Foods rich in creatine include:
    tuna, salmon, cod, beef and pork

  4. Been using creatine for years, cycling it one-and-off to get better results and avoid my system getting used to it.
    Enhancing cardio/endurance? Much research points to it not contributing to endurance enhancement, yet I tend to agree with your comment "increasing muscle mass can potentially help certain endurance athletes"... you know, in certain sports.

  5. She was probably taking creatine ethyl ester. In acid (like stomach acid) it converts to creatinine. Creatine is mainly excreted as creatine. Some of it converts to creatinine but most doesn't.