The energy needed by the cells of the body is produced in an intracellular organelle called mitochondria. Mitochondria are energy factories of our body. In many cells of the body, there are between 500 to 2000 mitochondria. But in the cells with higher level of activity, this number is more. For example, heart cells have up to 5000 mitochondria in each cell. Glucose as the most common fuel in our body is used in mitochondria and produces energy. The result of intracellular reactions in this organelle is the production of a substance called ATP or adenosine triphosphate. ATP is like the currency of a country and is used as a source of energy for various vital activities of our body.
Our body is also able to use other substances such as fats to produce energy. One role of L-carnitine is the ability to transport fat into the mitochondria for energy production. L-carnitine also removes some waste products from fat metabolism in the mitochondria.
Considering the role of L-carnitine in the production of energy in the body, it is useful for increasing endurance during exercise and also for consuming fats as fuel. Unlike skeletal muscles, our heart muscles do not have glycogen stores to convert into glucose. But instead, the heart is interested in using fatty acids as a source of fuel and energy production. Fatty acids are obtained from the metabolism and breakdown of fats in the body. L-carnitine is necessary for the transport of fatty acids into the mitochondria. As a result, L-carnitine is essential not only for athletes and weight loss but also for optimal heart function and health. L-carnitine may also be useful in alleviating the symptoms of patients with heart failure and angina pectoris.
L-carnitine is chemically an amino acid and is produced in the body from proteins. Elderly people may have difficulty in absorbing and digesting proteins, and for this reason, L-carnitine deficiency is more probable in this group of people. L-carnitine is made in the liver, kidneys and brain, and therefore people with kidney or liver failure are more likely to have L-carnitine deficiency.
Considering the role of L-carnitine in the metabolism of fats, it is possibly effective for improving hyperlipidemia (increased level of triglycerides or cholesterol in the blood).
In men, taking L-carnitine may be effective in improving the number and motility of sperms and treating infertility. (Note that sperms have a high level energy consumption). As a result, L-carnitine may be used alone or together with other vitamins and minerals in supplements used in infertility. L-carnitine is also useful in treating some forms of infertility in women.
Another interesting finding is that disruption of energy production in nerve cells plays a role in the occurrence of diabetic neuropathy (nerve pain in extremities) and L-carnitine can improve or prevent diabetic neuropathy.