Tag Archives: L – carnitine

L-Carnitine

Posted on 11. May, 2015 by .

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MP$$$$639PWhat is L carnitine

Carnitine, derived from an amino acid, is found in nearly all cells of the body.Made from lysine and methionine. There are a couple of different forms of carnitine, such as acetyl-L-carnitine and L-carnitine tartrate, and we’ll look at which forms you should be taking and when. In this article, unless otherwise stated, “carnitine” will be used to refer to L-carnitine tartrate.

Carnitine plays a critical role in energy production. It transports long-chain fatty acids into the mitochondria so they can be oxidized (“burned”) to produce energy. It also transports the toxic compounds generated out of this cellular organelle to prevent their accumulation. Given these key functions, carnitine is concentrated in tissues like skeletal and cardiac muscle that utilize fatty acids as a dietary fuel.The body makes sufficient carnitine to meet the needs of most people. For genetic or medical reasons, some individuals (such as preterm infants), cannot make enough, so for them carnitine is a conditionally essential nutrient.

How does it work?

L-carnitine helps the body produce energy. It is important for heart and brain function, muscle movement, and many other body processes.Take Carnitine to Burn Fat: Carnitine is a potent fat burner because it is responsible for the transport of fats into the cells to be used for energy in the body. By raising the level of muscle carnitine, you support the fat burning process, and because your body becomes more efficient at processing fuel, it will increase your energy levels.

Elevating carnitine will also improve physical performance by burning more fat, sparing glycogen, clearing muscle lactate, and optimizing hormone levels.

Carnitine Fights Visceral Belly Fat

Visceral belly fat is one of the toughest fats to lose once you’ve got it, and it causes numerous health problems. Once you begin to gain visceral fat around the belly, it will lead to fat gain within the organs such as the liver, the heart, or even in muscle.

Fat gain in the liver leads to non-alcoholic fatty liver disease, while epicardial fat is a type of visceral fat that is deposited around the heart and is considered a metabolically active organ, altering heart function.

Raising your carnitine levels will fight this visceral fat gain because it increases fat burning, which has the effect of taking triglycerides and low-density lipoproteins out of the system so that they don’t build up causing high cholesterol and atherosclerosis. A new research study in the journal Food and Chemical Toxicology illustrates this.

Researchers gave a carnitine supplement to mice who were fed a high-fat diet in order to make them gain weight. In comparison to a group of mice fed a placebo, the carnitine group gained substantially less visceral and subcutaneous fat (fat that is right below the surface of the skin that you can pinch with your fingers). The placebo group exhibited the beginning stages of non-alcoholic fatty liver disease and atherosclerosis, neither of which were evident in the carnitine group.

Serious kidney disease. Most research suggests that taking L-carnitine by mouth or intravenously (by IV) can improve red blood cell counts during hemodialysis. The US Food and Drug Administration (FDA) has approved L-carnitine for the treatment and prevention of L-carnitine deficiency in people with serious kidney disease who are undergoing hemodialysis.

L-carnitine deficiency. The FDA has approved L-carnitine for treating L-carnitine deficiency caused by certain genetic diseases.

Chest pain (angina). Taking L-carnitine by mouth seems to improve exercise tolerance in people with chest pain. Taking L-carnitine along with standard treatment also seems to reduce chest pain and improve exercise ability in people who have chest pain but not blocked arteries.

Alzheimer’s Disease and Memory Impairment

The evidence is mixed as to whether carnitine is useful in treating Alzheimer’s disease. Several early studies showed that acetyl-L-carnitine, might help slow down the progression of Alzheimer’s disease, relieve depression related to senility and other forms of dementia, and improve memory in the elderly. People should take carnitine for Alzheimer’s and other forms of dementia only under the supervision of their health care provider.

High thyroid hormone levels (hyperthyroidism). Taking L-carnitine seems to improve symptoms such as rapid or pounding heartbeat, nervousness, and weakness in people with high thyroid hormone levels.

Male infertility. Most research shows that taking L-carnitine, alone or in combination with acetyl-L-carnitine, increases sperm count and sperm movement in men with fertility problems.

Preventing side effects caused by valproic acid (Depacon, Depakene, Depakote, VPA), a seizure medication. Using L-carnitine intravenously (by IV) can prevent the side effects of valproic acid.

Heart failure. Taking L-carnitine by mouth seems to improve symptoms and increase exercise ability in people with heart failure. Taking a specific product containing L-carnitine and coenzyme Q-10 (Carni Q-Gel) also appears to improve symptoms of heart failure.

Inflammation of the heart (myocarditis). Taking L-carnitine by mouth seems to reduce the risk of death from myocarditis.

Use Carnitine for Better Skin
A topical carnitine cream can improve the health of your skin by decreasing the amount of oil released by the pores. A new study in the Journal of Cosmetic Dermatology found that a carnitine cream increased the amount of fat that entered the cell, which decreased the oil secreted by the skin.

This led to less oily skin and a smoother overall appearance. It also indicates the value of using carnitine to improve the transport of carnitine across the cellular wall to be burned for fat because Beta fat oxidation, or burning, was enhanced.

L-carnitine is LIKELY SAFE for most people when taken by mouth and when used as an injection, with the approval of a healthcare provider. It can cause side effects such as nausea, vomiting, stomach upset, heartburn, diarrhea, and seizures. It can also cause the urine, breath, and sweat to have a “fishy” odor.

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carnitine and L – carnitine

Posted on 23. Dec, 2011 by .

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L-Carnitine, a sub-type of Carnitine
Carnitine is a naturally occurring amino acid which plays a vital role in the metabolism of fat. It functions as a transporter of fatty acids into the mitochondria, the metabolic furnace of the cell.Carnitine is a substance that helps the body turn fat into energy. Your body makes it in the liver and kidneys and stores it in the skeletal muscles, heart, brain, and sperm
Carnitine plays a critical role in energy production. It transports long-chain fatty acids into the mitochondria so they can be oxidized (“burned”) to produce energy. It also transports the toxic compounds generated out of this cellular organelle to prevent their accumulation. Given these key functions, carnitine is concentrated in tissues like skeletal and cardiac muscle that utilize fatty acids as a dietary fuel
Usually, your body can make all the carnitine it needs. Some people, however, may not have enough carnitine because their bodies cannot make enough or can’ t transport it into tissues so it can be used. Some other conditions, such as angina or intermittent claudication, can also cause low levels of carnitine in the body, as can some medications.For genetic or medical reasons, some individuals (such as preterm infants), cannot make enough, so for them carnitine is a conditionally essential nutrient
Carnitine has been proposed as a treatment for many conditions because it acts as an antioxidant. Antioxidants fight harmful particles in the body known as free radicals, which damage cells and tamper with DNA. Antioxidants can neutralize free radicals and may reduce or help prevent some of the damage they cause.

Some of the conditions carnitine may help treat are serious. Serious diseases and conditions require conventional medical treatment, and you should talk to your health care provider before taking carnitine. For other conditions, such as fatigue or improving athletic performance, carnitine seems safe but may not help much.

L-carnitine was discovered in Russia, and one year later in Germany. The proper name, Carnitine, refers to the Latin origin, (carno, caris). Its structural formula was decoded in 1927, and its physiological significance was understood by the 1960’s. (http://www.hlthmall.com/l-carnitine.html) L-carnitine is synthesized in the liver and kidneys, from two essential amino acids, lysine and methionine. This synthesis requires the presence of vitamins niacin, B6, and iron. Most (98%) of the carnitine supply resides in the body’s muscle tissue. Approximately 80% of the amino acids our bodies need is endogenously synthesized, the remaining 20% are referred to as the essential amino acids. The supply of such aminos, like l-carnitine, must be supplemented exogenously. L-carnitine is available in the following food sources: red meat, diary products, avocado, and tempeh. Although a well balanced diet can provide approximately 75% of what the body is lacking, often conditions arise that make it difficult to obtain all the carnitine one needs.
It has been established that an adequate supply of l-carnitine is necessary for the maintenance of good health. L-carnitine transports long-chain fatty acids across the mitochondrial membrane to be metabolized. L-carnitine aids in the release of stored body fat, tryglycerides, into the bloodstream for energy. Tryglycerides are the major source for the production of energy in the heart and skeletal muscles. Access to l-carnitine is believed to increase energy levels for long-term aerobic activity. L-carnitine is also responsible for muscle contraction, regulation of protein balance and maintenance of a healthy heart. Research also suggests that an adequate supply of l-carnitine could be instrumental in the treatment of diabetes, chronic fatigue syndrome, kidney and liver disease.Since its involvement in the process of burning fats is of most importance to those interested in endurance and body fitness, it is this topic that will be focused upon.

THE ROLE OF L-CARNITINE: HOW DOES IT WORK?

Carnitine boosts energy by stimulating the body’s burning of tryglycerides as fuel, and sparing the supply of glycogen stored in the liver for heavier exertion. During exercise, the body will burn fat at a rate of 75-80% of maximum exertion, thus less glycogen from carbohydrates is burned. L-carnitine allows the body to burn more fat, save more glycogen, and ultimately boost stamina and endurance. By providing more fat to the muscles, carnitine makes accessible an otherwise unavailable energy source

FAT + OXYGEN + L-CARNITINE = ENERGY

Is this the recipe for success? According to proponents of L-Carnitine, it is the essential amino acid in the optimum fat burning process. They believe that carnitine is to the human body, what a turbo mechanism is to a car: both provide optimal fuel and performance. Minus L-carnitine, fatty acids would have a difficult time permeating the walls of the mitochondria. Energy, stored in carbohydrates and fats, is required to work the muscle. Carbohydrates are converted from glucose to glycogen, to be stored in liver and muscle cells. Eventually, the body turns to fat storage for energy, and possibly, with more ease in the presence of L-carnitine. This is where L-carnitine as a supplement enters. During high energy output, the supply of L-carnitine becomes exhausted. Is it possible to compensate for this decrease solely through metabolic processes and diet? Or is an additional carnitine supplement needed for the extra boost? Judging from the variety of carnitine products now on the market, apparently many believe an additional outside source proves beneficial.

L-carnitine supplements are used to increase L-carnitine levels in people whose natural level of L-carnitine is too low because they have a genetic disorder, are taking certain drugs (valproic acid for seizures), or because they are undergoing a medical procedure (hemodialysis for kidney disease) that uses up the body’s L-carnitine. It is also used as a replacement supplement in strict vegetarians, dieters, and low-weight or premature infants.

L-carnitine is used for conditions of the heart and blood vessels including heart-related chest pain, congestive heart failure (CHF), heart complications of a disease called diphtheria, heart attack, leg pain caused by circulation problems (intermittent claudication), and high cholesterol.

Some people use L-carnitine for muscle disorders associated with certain AIDS medications, difficulty fathering a child (male infertility), a brain development disorder called Rett syndrome, anorexia, chronic fatigue syndrome, diabetes, overactive thyroid, attention deficit-hyperactivity disorder (ADHD), leg ulcers, Lyme disease, and to improve athletic performance and endurance.

The body can convert L-carnitine to other amino acids called acetyl-L-carnitine and propionyl-L-carnitine. But, no one knows whether the benefits of carnitines are interchangeable. Until more is known, don’t substitute one form of carnitine for another.

When can a carnitine deficiency occur?

Two types of carnitine deficiency states exist. Primary carnitine deficiency is a genetic disorder of the cellular carnitine-transporter system that usually manifests itself by five years of age with symptoms of cardiomyopathy, skeletal-muscle weakness, and hypoglycemia. Secondary carnitine deficiencies may occur due to certain disorders (such as chronic renal failure) or under particular conditions (e.g., use of certain antibiotics) that reduce carnitine absorption or increase its excretion . There is scientific agreement on carnitine’s value as a prescription product for treating such deficiencies .

What are some current issues and controversies about carnitine?

Carnitine has been studied extensively because it is important to energy production and is a well-tolerated and generally safe therapeutic agent . Researchers prefer to use acetyl-L-carnitine in research studies because it is better absorbed from the small intestine than L-carnitine and more efficiently crosses the blood-brain barrier (i.e., gets into brain tissue) .

Athletic performance

Some athletes take carnitine to improve performance. However, twenty years of research finds no consistent evidence that carnitine supplements can improve exercise or physical performance in healthy subjects—at doses ranging from 2-6 grams/day administered for 1 to 28 days. (The total body content of carnitine is about 20 grams in a man weighing 155 pounds, almost all of it in the skeletal muscle .) For example, carnitine supplements do not appear to increase the body’s use of oxygen or improve metabolic status when exercising, nor do they necessarily increase the amount of carnitine in muscle.

Aging

A decline in mitochondrial function is thought to contribute to the aging process. Carnitine may be involved because its concentration in tissues declines with age and thereby reduces the integrity of the mitochondrial membrane
. Research in aged rats found supplementation with high doses of acetyl-L-carnitine and alpha-lipoic acid (an antioxidant) to reduce mitochondrial decay
. The animals also moved about more and improved their performance on memory-requiring tasks. At present there are no equivalent studies of this kind in humans. However, a meta-analysis of double-blind, placebo-controlled studies suggests that supplements of acetyl-L-carnitine may improve mental function and reduce deterioration in older adults with mild cognitive impairment and Alzheimer’s disease
. In these studies, subjects took 1.5-3.0 grams/day of acetyl-L-carnitine for 3-12 months.

Cardiovascular and peripheral-arterial disease
Several studies have examined supplemental carnitine in the management of cardiac ischemia (restriction of blood flow to the heart) and peripheral arterial disease (of which the most important symptom is poor circulation in the legs, known as intermittent claudication)
. Because levels of carnitine are low in the failing heart muscle, supplemental amounts might be beneficial to the organ by counteracting the toxic effects of free fatty acids and improving carbohydrate metabolism
. In short-term studies, carnitine has demonstrated anti-ischemic properties when given orally and by injection. A double-blind, placebo-controlled, multicenter clinical trial in Italy with patients who had suffered a first heart attack found that supplemental carnitine (given intravenously for five days, then 6 grams/day orally for one year) reduced heart failure and overall mortality
. The results were not conclusive but promising enough to justify a larger study whose results have not yet been reported

Claudication results from an inadequate supply of oxygen-rich blood to the legs and leads to an accumulation of acetylcarnitine in muscle due to its incomplete utilization. Patients with peripheral arterial disease who develop claudication have significant impairments in exercise performance and find it difficult to walk even short distances at a slow speed
. Two published randomized, controlled trials raise the possibility that carnitine may improve the performance of skeletal muscles in the leg. In one European multicenter clinical trial, subjects with moderate to severe claudication who were supplemented with L-carnitine (in the form of propionyl-L-carnitine at 2 grams/day for 12 months) significantly improved their maximal walking distance and perceived quality of life as compared to subjects receiving the placebo [21]red for 6 months in patients with disabling claudication to significantly improve walking distance and speed, reduce bodily pain, enhance physical function, and improve perceived health state as compared to controls.

Cancer

Fatigue resulting from chemotherapy, radiation treatment, and poor nutritional status is common in cancer patients
. They may also be deficient in carnitine
. In one study, treatment with carnitine supplements (4 grams/day for one week) ameliorated fatigue in most chemotherapy-treated subjects and restored normal blood levels of carnitine
. In another trial, terminal cancer patients supplemented with carnitine (doses ranged from 250 milligrams to 3 grams/day) experienced less fatigue and improved mood and quality of sleep
. In both studies, most subjects were carnitine deficient before taking the supplements.

Type 2 diabetes

Insulin resistance, which plays an important role in the development of type 2 diabetes, may be associated with a defect in fatty-acid oxidation in muscle. This raises the question as to whether mitochondrial dysfunction might be a factor in the development of the disease. Increased storage of fat in lean tissues has become a marker for insulin resistance . Early research suggests that supplementation with L-carnitine intravenously may improve insulin sensitivity in diabetics by decreasing fat levels in muscle and may lower glucose levels in the blood by more promptly increasing its oxidation in cells. A recent analysis of two multicenter clinical trials of subjects with either type 1 or type 2 diabetes found that treatment with acetyl-L-carnitine (3 grams/day orally) for one year provided significant relief of nerve pain and improved vibration perception in those with diabetic neuropathy. The treatment was most effective in subjects with type 2 diabetes of short duration.

HIV and AIDS

The human immunodeficiency virus (HIV) causes a decline in the number of lymphocytes (one type of white blood cell), resulting in acquired immunodeficiency syndrome (AIDS). HIV-infected individuals often accumulate fat in some areas of the body and lose fat in others and develop high levels of blood fats (hyperlipidemia) and insulin resistance, which together constitute the lipodystrophy syndrome. This syndrome may represent mitochondrial toxicity brought about by the HIV infection and the antiretroviral drugs used to treat it, and can induce a carnitine deficiency that limits mitochondrial fat metabolism . The molecular mechanisms by which this occurs are poorly understood. Preliminary research provides conflicting findings but suggests that supplementation with carnitine both intravenously and orally (at doses of 2-6 grams/day for weeks or months) in HIV-infected individuals may slow the death of lymphocytes (which in turn may slow HIV progression), reduce neuropathy , and favorably affect blood lipid levels .

End-stage renal disease and hemodialysis

Carnitine homeostasis (balance within the body) among individuals with renal diseases can be substantially impaired by several factors, particularly reduced synthesis and increased elimination of the compound by the kidneys as well as reduced intake from food due to poor appetite and consumption of fewer animal products . Many patients with end-stage renal disease, particularly those on hemodialysis, become carnitine insufficient. Carnitine blood levels and muscle stores are low, which may contribute to anemia, muscle weakness, fatigue, altered levels of blood fats, and heart disorders. Numerous studies suggest that high doses of supplemental carnitine (often injected) in patients on maintenance hemodialysis can correct some or all of these symptoms, though most involve small numbers of patients and are not double-blinded trials. A recent meta-analysis of these studies concludes that carnitine supplements may aid anemia management but not blood-lipid profiles, and that their effects on exercise capacity or heart stability are inconclusive .

Male infertility

Low sperm counts have been linked to low carnitine levels in men. Several studies suggest that L-carnitine supplements may increase sperm count and mobility.

Erectile Dysfunction

Preliminary studies suggest propionyl-L-carnitine may help improve male sexual function. One study found that carnitine improved the effectiveness of sidenafil (Viagra) in men with diabetes who had not previously responded to Viagra. In another study, a combination of propionyl-L-carnitine and acetyl-L-carnitine improved the effectiveness of Viagra in men who had erectile dysfunction after prostate surgery. More studies are needed.

Peyronie’s Disease

Peyronie’s disease is characterized by a curvature of the penis that leads to pain during an erection. One promising study compared acetyl-L-carnitine to the medication tamoxifen in 48 men with this condition. Acetyl-L-carnitine worked better than tamoxifen at reducing pain during sex and reducing the curve of the penis. Acetyl-L-carnitine also had fewer side effects than tamoxifen. More research is needed.

The carnitine content of seminal fluid is directly related to sperm count and motility , suggesting that the compound might be of value in treating male infertility. Several studies indicate that carnitine supplementation (2-3 grams/day for 3-4 months) may improve sperm quality, and one randomized, double-blind crossover trial found that 2 grams/day of carnitine taken for 2 months by 100 infertile men increased the concentration and both total and forward motility of their sperm . The reported benefits may relate to increased mitochondrial fatty-acid oxidation (providing more energy for sperm) and reduced cell death in the testes . However, a recent randomized controlled trial with 21 infertile men found that 3 grams/day of carnitine taken for 24 weeks produced no significant increases in sperm motility or total motile sperm counts as compared to placebo . Larger and more carefully designed studies are needed to evaluate carnitine’s potential value as an infertility therapy.

Are there health risks from too much carnitine?

At doses of approximately 3 grams/day, carnitine supplements may cause nausea, vomiting, abdominal cramps, diarrhea, and a “fishy” body odor . More rare side effects include muscle weakness in uremic patients and seizures in those with seizure disorders.

Carnitine and medication interaction

Carnitine interacts with pivalate-conjugated antibiotics such as pivampicillin that are used in the long-term prevention of urinary-tract infections . Chronic administration of these antibiotics increases the excretion of pivaloyl-carnitine, which can lead to carnitine depletion. However, while tissue carnitine levels may become low enough to limit fatty acid oxidation, no cases of illness due to deficiency have been described . Blood concentrations of carnitine may be reduced in children treated for convulsions with phenobarbital, valproic acid, phenytoin, or carbamazepine, but no clinical consequences have been shown .

Supplemental sources of carnitine

L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine are available over-the-counter as dietary supplements. Carnitine is often promoted as an aid for weight loss, to improve exercise performance, and to enhance a sense of well-being . It is also a drug approved by the Food and Drug Administration to treat primary and certain secondary carnitine-deficiency syndromes.

Carnitine intakes and healthful diets

Most people obtain sufficient carnitine because of the body’s natural production of the substance as well as from their diets. The Dietary Guidelines for Americans describes a healthy diet as one that:

* emphasizes a variety of fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products;
* includes lean meats, poultry, fish, beans, eggs, and nuts;
* is low in saturated fats, trans fats, cholesterol, salt (sodium), and added sugars; and
* stays within your daily calorie needs.

Heart Conditions

* Angina — Some good evidence shows that carnitine can be used along with conventional treatment for stable angina. Several clinical trials show that L-carnitine and propionyl-L-carnitine can help reduce symptoms of angina and improve the ability of people with angina to exercise without chest pain. Do not self-treat chest pain with carnitine, however. See your health care provider for diagnosis and conventional treatment, and take carnitine only under your health care provider’s supervision.
* Heart attack — A few studies have found that carnitine may help when used with conventional medicines after a heart attack, but not all studies agree. Some small studies suggest that people who take L-carnitine supplements soon after a heart attack may be less likely to have another heart attack, die of heart disease, have chest pain and abnormal heart rhythms, or develop heart failure. However, other studies have shown no benefit. Treatment with oral carnitine may also improve muscle weakness. Carnitine should be used along with conventional medication under your health care provider supervision.
* Heart failure — A few small studies have suggested that carnitine (usually propionyl-L-carnitine) can help reduce symptoms of heart failure and improve exercise capacity in people with heart failure. However, more and larger studies are needed to know for sure.

Peripheral Vascular Disease

Decreased blood flow to the legs from atherosclerosis or hardening of the arteries — where plaque builds up in the arteries — often causes an aching or cramping pain in the legs while walking or exercising. This pain is called intermittent claudication, and the reduced blood flow to the legs is called peripheral vascular disease (PVD). Several studies show that carnitine can help reduce symptoms and increase the distance that people with intermittent claudication can walk. Most studies have used propionyl-L-carnitine. Scientists don’t know whether L-carnitine would work the same.

Diabetic Neuropathy

Diabetic neuropathy happens when high blood sugar levels damage nerves in the body, especially the arms, legs, and feet, causing pain and numbness. Some small preliminary studies suggest acetyl-L-carnitine may help reduce pain and increase feeling in affected nerves. It is also possible that carnitine can help nerves regenerate. More research is needed.

Exercise Performance

Although carnitine is often taken to boost exercise performance, there is no evidence it works.

Weight Loss

Although L-carnitine has been marketed as a weight loss supplement, there is no scientific evidence to show that it works. Some studies do show that oral carnitine reduces fat mass, increases muscle mass, and reduces fatigue, which may contribute to weight loss in some people.

Alzheimer’s Disease and Memory Impairment

The evidence is mixed as to whether carnitine is useful in treating Alzheimer’s disease. Several early studies showed that acetyl-L-carnitine, might help slow down the progression of Alzheimer’s disease, relieve depression related to senility and other forms of dementia, and improve memory in the elderly. But larger and better-designed studies found it didn’ t help at all. People should take carnitine for Alzheimer’s and other forms of dementia only under the supervision of their health care provider.

Kidney Disease and Dialysis

Because the kidneys make carnitine, kidney disease could lead to low levels of carnitine in the body. If you have kidney disease, your health care provider may prescribe carnitine — but you shouldn’ t take it without medical supervision.

Hyperthyroidism

Some research suggests that L-carnitine may help prevent or reduce symptoms of an overactive thyroid, such as insomnia, nervousness, heart palpitations, and tremors. In fact, in one study, a small group of people with hyperthyroidism saw these symptoms improve, and their body temperature become normal, when taking carnitine. But a larger, better-designed clinical trial is needed to see if carnitine really works. In addition, researchers think carnitine may work by blocking the action of thyroid hormone, which could be dangerous for people with low thyroid levels. Don’ t take carnitine for hyperthyroidism without your doctor’ s supervision.

Dietary Sources:

Red meat (particularly lamb) and dairy products are the main food sources of carnitine. It can also be found in fish, poultry, tempeh, wheat, asparagus, avocados, and peanut butter.
Available Forms:

Carnitine is available as a supplement in a variety of forms.

* L-carnitine: the most widely available and least expensive
* Acetyl-L-carnitine: Often used in studies for Alzheimer’s disease and other brain disorders
* Propionyl-L-carnitine: Often used in studies for heart disease and peripheral vascular disease

Avoid D-carnitine supplements. They interfere with the natural form of L-carnitine and may produce unwanted side effects.

In some cases, L-carnitine may be taken by prescription or given intravenously by a health care provider.
How to Take It:

Pediatric

Don’ t give carnitine supplements to a child without your child’s health care provider’s supervision. Your child’s health care provider should first make sure that the child has a carnitine deficiency.

Adult

Recommended doses of L-carnitine vary depending on the health condition being treated. The usual dose is between 1 – 3 g per day.
Precautions:

Because supplements may have side effects or interact with medications, you should take them only under the supervision of a knowledgeable health care provider.

Side effects are generally mild. High doses (5 or more grams per day) may cause diarrhea. Other rare side effects include increased appetite, body odor, and rash.

People with the following conditions should talk to their health care provider before taking carnitine:

* Peripheral vascular disease
* High blood pressure
* Liver disease from alcoholism (cirrhosis)
* Diabetes
* Kidney disease
* History of seizures

Possible Interactions:

If you are being treated with any of the following medications, you should not use carnitine without first talking to your health care provider.

AZT — In a laboratory study, L-carnitine supplements protected muscle tissue against toxic side effects from AZT, a medication used to treat HIV and AIDS. More studies are needed to know whether L-carnitine would have the same effect in people.

Doxorubicin — Treatment with L-carnitine may protect heart cells against the toxic side effects of doxorubicin, a chemotherapy medication used to treat cancer, without making the medication any less effective. Always talk to your oncologist before using any complementary or alternative therapy with chemotherapy.

Isotretinoin (Accutane) — Accutane, a strong medication used for severe acne, can cause liver problems, as measured by a blood test, as well as high cholesterol and muscle pain and weakness. These symptoms are like those seen with carnitine deficiency. Researchers in Greece showed that a large group of people who had side effects from Accutane got better when taking L-carnitine compared to those who took a placebo.

Thyroid hormone — Carnitine may stop thyroid hormone from getting into cells, and theoretically may make thyroid hormone replacement less effective. If you take thyroid replacement hormone, talk to your health care provider before taking carnitine.

Valproic acid (Depakote) — The anti-seizure medication valproic acid may lower blood levels of carnitine. Taking L-carnitine supplements may prevent any deficiency and may also reduce the side effects of valproic acid. However, taking carnitine may increase the risk of seizures in people with a history of seizures.
Alternative Names:

Acetyl-l-carnitine; L-carnitine

thank you and reference
http://www.webmd.com
http://www.vanderbilt.edu
http://www.carnitine.com
http://ods.od.nih.gov
http://www.umm.edu
http://www.nutritional-supplements-health-guide.com
http://www.drweil.com
http://www.naturalremedies.org/l-carnitine

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