Creatine Case Study

Case Study

History

Learning Goals /
Concept Map


Creatine and Related Compounds

Structure

Amino Acids

Creatine in the Body

Equilibrium

Creatine-Creatinine Equilibrium

Creatinine Test for Kidney Function

Detection

Regulation and Ethics

Amine & Nitrile Chemistry

Laboratory Synthesis

Chemical Analysis

Creatine-Phosphocreatine Equilibrium

Uses & Side Effects


Creatine in the Body

Locations of Creatine Synthesis in the Body


Roll over organs to see where creatine is synthesized in the body.

Amount of Creatine in the Body and Dietary Sources of Creatine
The body makes approximately 1 to 2 grams creatine a day, and an additional 1 to 2 grams of creatine may be acquired in the diet from foods such as meat and fish.[1,2] 

Source

Amount of Creatine, g/kg [3,4]

Tuna

3

Cod

4

Salmon

4.5

Pork

5

Uncooked Muscle Meat

3-6

Raw Herring

10

The cooking process results in some degradation of creatine into creatinine.  Cooking of beef, chicken, or rabbit usually results in less than 5% degradation of creatine into creatinine, whereas boiling or stewing meat for one hour results in approximately 30% degradation of creatine into creatinine.  In contrast, air dried meats, such as beef jerky, which may contain up to 13 grams of creatine per kilogram, retain 90% of their creatine content.[3]

Most vegetables and non-vertebrate sources of meat do not contain creatine.[3]  Although trace amounts of creatine can be found in cranberries and milk,[4] strict vegetarians or those who consume heavily processed or cooked meat may not obtain any creatine from their diets.[3]

Most people store only 60-80% of the creatine they obtain through diet and natural synthesis.[5]  The amount of creatine in a person’s body depends largely on that person’s muscle mass.  Specifically, skeletal muscle contains approximately 125 mmol of creatine per kg of dry muscle.[2,3] Typically, a 154 lb (70 kg) individual has approximately 120 grams of creatine in his or her body.[2]  Roughly 2 grams of creatine is lost daily due to degradation creatine into creatinine.[1,3,4] Therefore, 1.7% of the total creatine pool in the human body is lost every day.[2,3]  (Read more about the CREATINE-CREATININE EQUILIBRIUM, and the CREATININE TEST FOR KIDNEY FUNCTION.)  However, because creatine is synthesized in the liver, kidneys, and pancreas at a rate of approximately 2 grams per day, the daily loss and replacement of creatine in the body are nearly equal.[1]

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[1] Juhn, Mark S. “Oral Creatine Supplementation: Separating Fact from Hype.” The Physician and Sports Medicine. 1999, 27(5).
[2] Athletic Supplements: Creatine.  <http://www.geocities.com/HotSprings/Spa/9971/creatine.html> (accessed April 2009).
[3] Harris, Roger C. “Dietary and Supplementary Creatine.” <http://www.scitecnutrition.com/scifiles/dietary/dietary.htm> (accessed April 2002).
[4] Balsom, Paul D; Soderlund, Karin; Ekblom, Bjorn. “Creatine in Humans with Special Reference to Creatine Supplementation.” Sports Medicine. 1994, 18, 268-280.
[5] NutraSense. <http://www.nutrasense.com/nutrasense/creathisandp.html> (accessed April 2002).