L-Carnitine Benefits, Sources, Dosage And Deficiency

L-Carnitine Benefits, Sources, Dosage And Deficiency

Another component (apart from Inositol) that helps in converting the body fat into energy is L-Carnitine. To know more about L-Carnitine including its functions in the human body, its sources, dosage & other important considerations, read the below given article.

What Is L-Carnitine?

L-Carnitine is an amino acid derivative and is derived from L-Lysine and L-Methionie Amino Acids. However, L-Carnitine is not an amino acid. Chemically, L-Carnitine is classified as a quaternary amine. L-Carnitine is found in almost all cells of the body as it is synthesized in the human liver and kidneys. Once it is produced in the liver and kidneys it is transported and stored in the skeletal muscles, sperm, brain and heart of the humans. It must be noted that the skeletal muscles and cardiac muscles mainly use fatty acids for optimum performance. L-Carnitine is a water soluble and is very similar to Choline. It is also known as Carnitine, Acetyl-l-Carnitine, levocarnitine and also as Vitamin BT.

L-Carnitine is a ‘conditionally essential nutrient’ for the humans and is a chiral molecule. L-Carnitine has a stereo-isomer that antagonizes its functions and is known as D-carnitine.

How Does L-Carnitine Work?

L-Carnitine works by transporting long chain fatty acids to the inner mitochondrial membranes of the Mitochondria. Here, they are converted into biological energy by the process of beta-oxidation. During the process of oxidation L-Carnitine is converted into adenosine triphosphate or ATP. It must be noted that all tissues in the human body (except the brain) need long chain fatty acids for deriving biological energy.

Apart from long chain fatty acids, L-Carnitine is also responsible for removing short and medium chain fatty acids from the mitochondria. Short and medium chain fatty acids get deposited in the mitochondria as a result of abnormal (and sometimes normal) metabolism process. L-Carnitine performs this function to maintain the Co-enzyme A level in the body and thereby helps in preventing fatty acid build up in the mitochondria.

Sources Of L-Carnitine


L-Carnitine is mainly found in meats such as beef (145m per 100 grams) & lamb, dairy products, fish & poultry, vegetables and grains. However, its concentration is generally less in vegetables (exceptions include Avocado, asparagus & fermented soy) and more in meat products. Thus, pure vegetarians are usually deficient in L-Carnitine than non-vegetarians.

Deficiency States Of L-Carnitine

Individuals suffering from angina and intermitted claudication, and also those taking some types of medications are found to be deficient in L-Carnitine. Similarly, vegetarians are also found to be deficient in L-Carnitine. There are two different deficiency states of L-Carnitine – Primary & Secondary.

Primary Carnitine Deficiency

muscle fatigue

Primary Carnitine deficiency may be due to hereditary disorders that lead to poor absorption of L-Carnitine from the diet. Primary Carnitine deficiency is classified into two – Systemic Deficiency and Myopathic Deficiency. Some of the possible signs of L-Carnitine deficiency in the body include – muscle fatigue, weakness and cramping.

Secondary Carnitine Deficiency


Secondary deficiency state of L-Carnitine is usually hereditary or acquired.  Secondary deficiency may be due to excessive loss of Carnitine from the body, insufficient synthesis of L-Carnitine in the body and also due to mal-absorption of L-Carnitine from the diet. Secondary deficiency is usually rare in humans. However, pre-mature babies, lactating mothers, children and vegetarians are more likely to suffer from this state of L-Carnitine deficiency.

Benefits Of L-Carnitine

L-Carnitine has many anti-oxidant properties and therefore, it effectively fights free radicals in the body. Some of the possible benefits our body derives from L-Carnitine include:

For A Healthy Heart

Many of the conditions related to the human heart can be effectively reduced by L-Carnitine. Using L-Carnitine supplements along with their usual treatment can give positive results in those with stable Angina. Many studies have also shown that propionyl-L-carnitine can be used effectively to reduce the symptoms related to Angina.

heart issue

The supplementation also helps such patients to continue exercising without getting frequent chest pain. Apart from Angina, L-Carnitine & propionyl-L-carnitine also help patients getting treated for cardiac arrest. It also reduces the symptoms associated with heart failure.

For Treating Peripheral Vascular Disease

Few studies have shown that taking propionyl-L-carnitine can help patients suffering from intermitted claudication, atherosclerosis and peripheral vascular disease (PVD). In PVA patients generally have reduced blood flow to the legs and have difficulty in walking.

For Treating Diabetic Neuropathy

arm pain

Acetyl-L-carnitine supplements can help reduce some of the symptoms associated with diabetic neuropathy such as nerve damages in the arms and legs leading to numbness and pain.

For Athletes


L-Carnitine supplements are usually taken by athletes to improve their endurance and to boost their overall performance.

For Weight Loss

weight loss

Few studies claim that L-Carnitine supplements are helpful in weight loss treatments as it reduces the fat deposits and increases the muscle mass.

For Kidney Related Ailments


Since L-Carnitine is synthesized in the kidneys, aliments like kidney failure may lead to its excessive loss from the body. Doctors usually prescribe L-Carnitine supplements for treating kidney related ailments.

For Treating Male Infertility

Male Infertility

Low sperm counts, erectile dysfunction & Peyronie’s Disease (curvature of the penis) in men can be mainly due to low levels of L-Carnitine in the body. Therefore, L-Carnitine, Acetyl-L-carnitine (for Peyronie’s Disease) & propionyl-L-carnitine (for erectile dysfunction) supplementation can help treat such disorders in men.

Other Benefits Of L-Carnitine

For treatment against the following disorders – Alzheimer’s disease & Memory Impairment (Acetyl-L-carnitine), Hyperthyroidism, aging (Acetyl-L-Carnitine) and degenerative cerebellar ataxia.



1 – 3 grams per day in adults.  For those suffering from heart related ailments a dosage level of 2 grams of L-Carnitine per day for 4 weeks can largely reduce the symptoms (based on a scientific study).

Overdose & Side Effects


Taking more than 5 grams per day of Carnitine may lead to mild side effects like diarrhea, rash, body odor and increased appetite, and serious side effects like high BP & palpitation.



Do not use L-Carnitine especially in infants, pregnant women, lactating mothers and children. For those suffering from any other serious ailments (especially epilepsy) must always consult their health care practitioner before going ahead with L-Carnitine supplementation. Do not take L-Carnitine after dinner as it may lead to sleep disturbances. Completely avoid D-Carnitine supplements.


Carnitine supplements are generally prescribed by doctors for treating cardiac ischemia and peripheral arterial disease. Some studies point to the fact that L-Carnitine has anti-oxidant properties that help in protecting ischemic heart from reperfusion injury. L-carnitine deficiency usually occurs in individuals getting treatment for chronic ailments and therefore, its supplementation may help reverse some of the symptoms associated with the particular disease. This supplement is effective but only when taken under proper medical guidance. Self-treatment using L-Carnitine supplements can often be very dangerous.


L-Carnitine is available in the following forms in the market – Oral L-Carnitine, Intravenous L-Carnitine (also known as levocarnitine), Acetyl-L-carnitine and proprionyl-L-carnitine (only available in Europe). Oral L-Carnitine and Intravenous L-Carnitine are available as prescription drugs for the treatment of L-Carnitine deficiencies.

Possible Drug Interaction

Drug Interactions

Few studies have shown interactions of L-Carnitine supplements with the following drugs – positively interacts with AZT & protects muscle loss (treatment for HIV/AIDS), positively interacts with Doxorubici & protects heart cells (chemotherapy treatment), positively interacts with Isotretinoin (Accutane) & protects liver (treatment for severe acne) and Valproic acid (Depakote). L-Carnitine may have adverse effect when taken along with drugs for Thyroid treatment.