Creatine is a dietary supplement that is often used to improve athletic performance. Excessive use of creatine can strain the kidneys and cause kidney damage. Individuals should follow proper dosing recommendations for creatine and consult a physician prior to taking supplements. Individuals who currently take creatine and have kidney problems should discontinue use of creatine to prevent further kidney damage.
Creatine is an amino acid that is synthesized in the kidneys and liver and supports muscle growth and contraction, according to Peace Health. Creatine is naturally available in fish and meat and is also marketed to athletes as a performance-enhancing supplement. According to the Mayo Clinic, the most popular creatine supplement is creatine monohydrate. Prolonged use or high doses of creatine may contribute to kidney damage.
Kidneys and Creatinine
Kidneys remove waste from the body, help form red blood cells and help regulate blood pressure. Creatinine is a chemical waste product of creatine. It is usually filtered out through the kidneys and excreted in the urine. High levels of creatinine in the blood can be caused by high doses of creatine and may be a sign of kidney damage and the inability of the kidneys to filter out creatinine.
MedlinePlus says kidney problems that are associated with high creatinine levels include acute tubular necrosis, diabetic nephropathy, glomerulonephritis or pyelonephritis, all of which can lead to chronic kidney disease (CKD) or kidney failure. CKD and kidney failure can result in seizures, coma and, ultimately, death. Individuals with either condition may need dialysis, a regular treatment that cleans the blood, or a kidney transplant.
According to the Mayo Clinic, normal blood creatinine is 0.6 to 1.2 mg/dL. Men usually have higher creatinine levels than women because creatinine increases with muscle mass. High creatinine can be caused by dehydration, certain medications and creatine supplements.
The University of Maryland Medical Center says the risk of kidney damage is greater when high doses of creatine supplements are taken. The Mayo Clinic does not advise taking more creatine than is recommended by manufacturers. A normal loading dose for an athlete prior to an athletic event is 5g, four times a day for a week. A maintenance dose for athletes is 2 to 5g per day.
Warnings and Considerations
According to MedlinePlus, possible side effects of creatine supplements include upset stomach, loss of appetite, diarrhea, nausea, muscle cramps, heat intolerance, fever, dehydration, reduced blood volume, electrolyte imbalances, increased thirst, headache, anxiety, irritability, aggression, nervousness, sleepiness, depression, abnormal heart rhythm, fainting or dizziness, blood clots in the legs, seizure and swollen limbs.
Creatine supplements are not regulated by the Food and Drug Administration. Many of the health and performance claims for creatine have not been scientifically substantiated. Peace Health advises that creatine should only be taken after consultation with a doctor or pharmacist. Creatine may not be appropriate for pregnant or breastfeeding women and children. It should not be taken by people with kidney or liver disease due to the risk of further kidney damage and altered liver function.