JCI l Carnitine in omnivorous diets induces an atherogenic gut microbial pathway in humans Early research into L carnitine was often cited as underwhelming, showing negligible changes in muscle carnitine content and fat loss outcomes. However, these findings may have been limited by a short study window L Carnitine Vitamin Supplement for Energy and Metabolism Boost Carnitine and hemodialysis American Journal of Kidney Diseases