I came across this when perusing for Acetyl L- Carnitine information:
http://www.ncbi.nlm....pt=AbstractPlus
This study was undertaken to investigate the bioavailability of various L-carnitine esters (acetyl-L-carnitine and lauroyl-L-carnitine) and salts (L-carnitine L-tartrate, L-carnitine fumarate, L-carnitine magnesium citrate) relative to base of free L-carnitine. Six groups of five or six piglets each were administered orally a single dose of 40 mg L-carnitine equivalents/kg body weight of each of those L-carnitine compounds. A seventh group served as a control. Free and total plasma carnitine concentrations were determined 1, 2, 3.5, 7, 24, and 32 hours after administration of the single dose. Area-under-the-curve (AUC) values were calculated to assess the bioavailability of the L-carnitine compounds. AUC values, calculated for the time interval between 0 and 32 hours, for both free and total carnitine were similar for base of free L-carnitine and the three L-carnitine salts (L-carnitine L-tartrate, L-carnitine fumarate, L-carnitine magnesium citrate) while those of the two esters (acetyl-L-carnitine, lauroyl-L-carnitine) were lower. Administration of L-carnitine L-tartrate yielded a higher plasma free carnitine AUC value for the time interval between 0 and 3.5 hours than administration of the other compounds. The data of this study suggest that L-carnitine salts have a similar bioavailability to that of free L-carnitine while L-carnitine esters have a lower one. The study also suggests that L-carnitine L-tartrate is absorbed faster than the other L-carnitine compounds.
This article states that Choline supplementation may increase L-Carnitine bioavailability:
http://www.pdrhealth.../lca_0060.shtml
The above article also stated:
In one study only 20% of a 2-gram dose of L-carnitine was found to be absorbed following ingestion. Most of an ingested dose of L-carnitine is absorbed by the small intestine, apparently by facilitative diffusion and active transport. Following the administration of a dose of L-carnitine of 1,980 milligrams twice daily, the maximum plasma concentration level (Cmax) was 80 nanomoles per milliliter, and the time to maximum concentration (Tmax) occurred at 3.3 hours. The bioavailability of oral L-carnitine is about 15%. L-carnitine is not bound to plasma protein or albumin.
My conclusion: Many grams of ALCAR with Lipoic Acid and Choline. *grin*
