One of the enzymes in this pathway, γ-butyrobetaine hydroxylase, is absent from cardiac and skeletal muscle but highly expressed in human liver, testes, and kidney [4]. The rate of L-carnitine biosynthesis in vegetarians is estimated to be around 1.2 μmol/kg of body weight/day [7]. Omnivorous humans ingest 2-12 μmol/kg of body weight/day which represents 75% of body carnitine sources [8]. Neither renal reabsorption nor changes in dietary carnitine intake appear to affect the rate of endogenous carnitine synthesis [9]. Bioavailability of oral carnitine dietary supplements is only in the order of 14 to 18% of dose and unabsorbed L-carnitine is mostly degraded by micoorganisims in the large intestine