PDF) Effect of Acute and Chronic Oral L Carnitine Supplementation on Exercise Performance Based on the Exercise Intensity: A Systematic Review Intestinal microbiota metabolism of l carnitine, a nutrient in red meat, promotes atherosclerosis Nature Medicine A 2016 study suggested L carnitine could drop a key cardiovascular risk marker by up to 12%, which sounded promising at first., But follow up research told a more complicated story, with inconsistent PDF) Carnitine status of pregnant women: Effect of carnitine supplementation and correlation between iron status and plasma carnitine concentration