Carnitine is a vitamin-like substance that has a very important role in the body. It controls the
transport of fats to the only place they can be burned (i.e., the mitochondria). Without carnitine, fats don't
get in, and they don't get burned -- that means they get stored. There has been controversy whether carnitine
supplementation helps burn more fat because the body already makes some carnitine and it has been debatable
whether supplements can increase carnitine in the muscle, where most fat is burned. However a recent study
using stable isotopes (the gold standard for determining rates of fat oxidation) showed for the first time
that carnitine supplementation (3 g/day for 10 days) increased long chain fatty acid oxidation in healthy
subjects (1).
1. Muller, D.M., H. Seim, W. Kiess, H. Loster, and T. Richter. Effects of oral L-carnitine supplementation
on in vivo long-chain fatty acid oxidation in healthy adults. Metabolism. 51:1389-1391, 2002.
