[edit] Heart conditions
Carnitine is primarily used for heart-related conditions. Several clinical trials show that L-carnitine and propionyl-L-carnitine can be used along with conventional treatment for angina to reduce medication needs and improve the ability of those with angina to exercise without chest pain.[10][11] There is little evidence about a positive effect of the use of carnitine after a heart attack. Some studies suggest people taking L-carnitine may be less likely to suffer a subsequent heart attack or experience chest pain and abnormal heart rhythms.[12] However, other studies have not found similar benefits.[13] Further research on this subject is needed.[edit] Kidney disease and dialysis
Because kidneys produce carnitine, kidney disease may lead to the deficiency of carnitine in the body. Thus, carnitine may be prescribed to those with kidney disease.[14][edit] Effect in male infertility
The use of carnitine showed some promise in a controlled trial in selected cases of male infertility by improving sperm quality.[15] L-Carnitine supplementation has also shown to have beneficial effects in the treatment of varicocele, a major cause of male infertility. [16][edit] As a weight loss supplement
"Although L-carnitine has been marketed as a weight-loss supplement, there is no scientific evidence to show that it improves weight loss; however, some studies show that oral carnitine reduces fat mass, increases muscle mass, and reduces fatigue. All of these effects may indirectly contribute to weight loss."[17] Furthermore, whereas researchers in the 20th century failed to show that muscle carnitine content could be increased by dietary supplementation, this may have been in part due to inadequate lengths of the supplementation periods.[18] In 2011, researchers using L-carnitine L-tartrate supplementation for six months in a well-controlled study demonstrated not only increased muscle carnitine in subjects without carnitine deficiencies, but also an impact on muscle metabolism and performance; however, measurements of lipid oxidation were not taken in this study, and further research is needed.[19]Regular supplements of L-carnitine, however, contribute to energy metabolism and improved neurotransmitter function in the brain in elderly patients.[20]
