In a 1978 review on carnitine, it was noted that the carnitine content of foods had not been completely studied. However, by now we do know that since it is component of muscle that the greatest amount of carnitine is in meat, especially mutton, lamb and red meat. Chicken, fish, eggs and milk also have some carnitine.
Vegetables have no carnitine.
The average adult consumes 30 to 50 milligrams of carnitine per day from their food intake. Unfortunately we do not have more information concerning the actual weight content of carnitine in meat and other foods. The data may be available, but we have not seen it. If you are thinking of the positive effects that carnitine has on the heart, such as in energy efficiency, stroke recovery, cholesterol reduction, etc. Studies have shown that in order to receive adequate benefit to the heart, at least 500 milligrams to 750 milligrams of L-carnitine is required per day.