L-Carnitine: Useful As A Dietary Supplement Or Not

L-carnitine is a substance that the body needs to generate energy. If L-carnitine is missing, fats cannot be burned – and obesity threatens. Since L-carnitine is almost exclusively found in meat, vegans are at risk of an L-carnitine deficiency and are dependent on dietary supplements. We clarify whether L-carnitine makes sense as a dietary supplement or not.

L-Carnitine – The energy booster in the body

L-carnitine is a vitamin-like substance that is produced by the body itself from the two amino acids lysine and methionine with the help of a number of vital substances.

L-carnitine is particularly responsible for the generation of energy from fatty acids. It ensures that the long-chain fatty acids can be channeled into the mitochondria (the cells’ power plants), where they are then burned to produce energy.

L-Carnitine – A Weight Loss Pill?

If L-carnitine is missing in the body, the fats can no longer be burned for energy. They remain in the body and are transported to fat cells, where they contribute to obesity. As a result, one of the typical symptoms of an L-carnitine deficiency is obesity and obesity.

For this reason, L-carnitine is also repeatedly marketed as a means of increasing fat burning – in short as a weight loss pill. In reality, however, L-carnitine rarely shows satisfactory results in those who want to lose weight. An additional L-carnitine intake does not seem to lead to an increase in fat burning. On the contrary, in cancer patients, the administration of L-carnitine prevents weight loss (wasting).

L-carnitine deficiency – the risk groups

Not only the fat metabolism but also the glucose metabolism is positively influenced by L-carnitine. L-carnitine improves the insulin sensitivity of the cells and therefore counteracts the insulin resistance that is so typical of type 2 diabetes.

No wonder type 2 diabetics belong to the risk group for L-carnitine deficiency. However, it is not really known whether the L-carnitine deficiency in type 2 diabetes is a contributory cause or the consequence of diabetes.

Also in the risk group for L-carnitine deficiency are dialysis patients, i.e. people who have to undergo dialysis regularly to cleanse their blood due to kidney failure.

Because L-Carnitine is water soluble, dialysis removes it from the body. Consequently, dialysis patients must take L-carnitine regularly. Otherwise, they would suffer from a massive L-carnitine deficiency.

L-carnitine deficiencies can also result from severe liver diseases or chronic intestinal diseases. In all these cases, however, there is not only an L-carnitine deficiency but many other nutrients and vital substance deficiencies.

Even some antibiotics can cause an L-carnitine deficiency by making it more difficult to absorb or promoting increased excretion of L-carnitine.

L-carnitine deficiency – secondary or primary

In addition to all the secondary forms of L-carnitine deficiency mentioned, there is also the primary L-carnitine deficiency. This is a hereditary disorder that first appears around the age of five.

Since the energy gained with the help of L-carnitine supplies the heart and skeletal muscles in particular, it is precisely these two organ systems that suffer the most in the event of a primary L-carnitine deficiency. Cardiomyopathies (diseases of the heart muscle), skeletal muscle weakness, and also hypoglycemia (chronic low blood sugar) appear.

L-Carnitine Deficiency – Are Vegans At Risk?

Vegans are often mentioned in the same breath as diabetics and dialysis patients as predestined for L-carnitine deficiency. Yes, on some websites, vegans are right at the top of the risk groups for an L-carnitine deficiency – ahead of diabetics, dialysis patients, pregnant women, cancer patients, and those who are artificially fed.

It is often said that the body can produce L-carnitine itself, but this self-synthesis does not cover the need in any way. Therefore, you have to get most of the required L-carnitine with food. But that is not possible with a vegan diet.

While meat contains a lot of L-carnitine – beef significantly more than pork, poultry, fish, and dairy products – vegetables, grains, and nuts is rather low in L-carnitine. As a result, quite a few believe that vegans must suffer from a massive L-carnitine deficiency.

That this is not the case is shown by millions of vegans worldwide, very few of whom supplement L-carnitine and whose state of health is usually significantly better than that of most omnivores.

L-carnitine – The need

The carnitine daily requirement should be easily covered by self-synthesis (approx. 16 mg). For this, the organism needs sufficient lysine and methionine (two amino acids), as well as vitamins B3, B6, and C as well as iron.

With the usual food (containing animal products), an additional 32 mg per day is consumed on average. Vegetarians only take in around 2 mg of L-carnitine with food every day. Of course, it depends very much on what you eat (see table at the bottom: “Vegan foods with L-carnitine”).

It is now claimed in various places that the requirement is at least 200 mg of L-carnitine and can increase to 1,200 mg per day – depending on physical and psychological stress.

On the one hand, it is precisely on these pages that it is explained that vegans are threatened by L-carnitine deficiency, on the other hand, it is pointed out that even meat eaters can hardly ever get to 1,000 mg, which is why basically everyone has to take L-carnitine as a dietary supplement.

Of course, doubts arise here and it sounds more like you want to sell L-carnitine as a dietary supplement in any case, although it is not really necessary and such high L-carnitine doses can also have health disadvantages in the long term.

L-carnitine could also be harmful

First of all, L-carnitine is not considered an essential nutrient, precisely because it can be assumed that there is sufficient self-synthesis. Secondly, there are also negative studies on L-carnitine that specifically advise against taking the substance, e.g. B. the one from 2013 published in the New England Journal of Medicine. In it, researchers from the Cleveland Clinic explained why red meat could increase mortality and, conversely, why a plant-based diet can protect against cardiovascular disease.

The Cleveland scientists wrote: “Numerous studies have shown that the risk of atherosclerosis (killer number 1) is lower in vegans and vegetarians than in omnivores and that this cannot be solely due to lower cholesterol and fat intake. ”

The researchers found that 24 hours after consuming L-carnitine – whether via a steak or a supplement – certain gut bacteria convert the L-carnitine into a toxic substance called trimethylamine.

Trimethylamine is then processed in the liver into toxic TMAO (trimethylamine N-oxide). TMAO now flows through the body in the blood and promotes the formation of deposits on the blood vessel walls, which in turn can lead to heart attacks, strokes, and premature death.

Why vegans could easily eat a steak (if they wanted to)

Some animal species produce more L-carnitine in their tissues than others. Cattle and sheep produce particularly large amounts of L-carnitine. Therefore, it is generally advised to reduce the consumption of red meat. Because the more L-carnitine in the food, the more toxic TMAO is produced.

However, other sources with high levels of L-carnitine, such as L-carnitine supplements and energy drinks containing L-carnitine, should also be avoided.

However, it is forgotten that TMAO can also be formed in the intestine from choline. Choline, for example, is a component of lecithin.

So one would have to avoid the sources of choline as well. This includes eggs, poultry, fish, dairy, and any dietary supplement containing lecithin. So the problem cannot be hidden in the flesh alone.

And what about vegans? Is the choline from legumes, grains, and vegetable oils and the small amounts of L-carnitine from plant foods also turned into toxic TMAO? no, A vegan could even eat an 8-ounce steak without TMAO forming.

A longtime vegan was persuaded to do just that for a test. It was a long time before he – in the name of science – agreed to eat the steak. As a result, there was no trace of TMAO in his intestines.

Anyone who has been vegan for a long time has a completely different intestinal flora than people who regularly consume animal products. A longtime vegan who eats a healthy diet rich in fiber no longer has the intestinal bacteria that produce the toxic TMAO from L-carnitine and choline.

But how does a vegan get enough L-carnitine to cover their needs?

L-carnitine supply in vegans

As already explained above, L-carnitine is involved in the body’s energy production and is required directly in the cell by certain enzymes. There are three enzymes called carnitine acyltransferases. You need L-carnitine in order to smuggle the long-chain fatty acids into the mitochondria together with it so that energy can be produced from the fat.

Now one could assume that in vegans, who only take in very little L-carnitine with their food, the mentioned L-carnitine-dependent enzyme system is very sluggish. But that is not the case. Otherwise, most vegans would also be quite plump and overweight. As is well known, the opposite is more likely to be the case. In most cases, vegans belong to the lean part of the population.

In a 2008 study, researchers then also found (Karlic et al., Annals of Nutrition and Metabolism) that carnitine acyltransferases are 60 percent more efficient in vegans than in normal eaters. The corresponding genes were upregulated here, i.e. particularly active – a sign that the body adapts to the circumstances and gets along very well with small amounts of L-carnitine from food or increases its own production accordingly.

In addition, L-carnitine absorption is better in vegans than in normal eaters. The L-carnitine from food is therefore absorbed and used more extensively.

L-carnitine during pregnancy

But not only vegans are threatened by an L-carnitine deficiency, but also pregnant women – whether vegan or not – one often reads. During pregnancy, the L-carnitine level decreases due to the increased energy requirement.

In addition, the iron level often drops during pregnancy (also in pregnant women who eat meat), which makes it difficult to produce L-carnitine yourself, since iron is needed to produce L-carnitine.

However, we now know that falling iron levels also have an advantage and are possibly naturally so low during pregnancy, since the pregnant woman and consequently her child is better protected against infections.

It is conceivable that falling L-carnitine levels during pregnancy also make sense and could be beneficial. Especially when you consider that L-carnitine is supplemented by very few pregnant women – and yet most children are born healthy.

Of course, the iron levels should be optimized if the pregnant woman has too low a storage iron level (ferritin) and feels weak and tired. However, the usual iron supplementation, which already takes place (and usually leads to discomfort) when the pregnant woman shows no symptoms at all, could definitely be described as superfluous, if not even questionable.

L-carnitine in children

A similar scaremongering with regard to pregnancy is also practiced in children with regard to L-carnitine. It is said that their own synthesis is only fully developed after about 15 years of age. However, this could also mean that children need less L-carnitine than is assumed.

A 2004 study from The Children’s Hospital of Philadelphia concluded that a vegan diet had no effect on the body’s carnitine levels.

Babies, however, are always dependent on an external supply of L-carnitine. Therefore, breast milk is also extremely rich in carnitine, but only in the first few weeks. After about a month, the L-carnitine content of breast milk drops sharply – regardless of whether the mother is vegan or not.

No one knows whether this waste – similar to the iron level – might have advantages for the child and whether it was set up that way on purpose. Because it is well known that breast milk provides exactly the right amount of each nutrient that the child needs at any given time during the breastfeeding period.

Yes, one study even found that children who were fed carnitine-free baby food developed normally and showed no symptoms of an L-carnitine deficiency.

Nevertheless, carnitine-free baby food is of course not recommended. Because breast milk should always be a model for the composition of substitute foods – even if breastfeeding is not possible. And if breast milk contains L-carnitine, then infants should be fed appropriately and receive L-carnitine.

In children, an L-carnitine deficiency is said to show up in developmental disorders. However, no developmental disorders that could be attributed to an L-carnitine deficiency have been reported in healthy vegan children.

The emphasis here is on “healthy eating”. Because if a child is not fed healthily – whether vegan or eating normally – it could lack those substances that it needs for its own L-carnitine synthesis, which of course would very well lead to an L-carnitine deficiency. Here, however, the L-carnitine deficiency would not be the result of a specific diet, but simply of general malnutrition.

Case reports give the vegan diet a bad reputation

Unfortunately, individual case reports of vegan malnourished children, such as those from 1992, are circulating again and again on the island hospital of the University of Bern, a 7.5-month-old child arrived with developmental disorders, goiter, hypotonia, and severely reduced bone density. The laboratory values showed an extremely high TSH value, low thyroxine values (free T4) – i.e. hypothyroidism – a calcium deficiency, a general calorie deficiency, and an L-carnitine deficiency.

The child had been breastfed until 2.5 months of age. Then – for 5 months – it had been given diluted almond milk. According to the summary of the case report, the mother was a strict vegan and the father was a Lacto-vegetarian.

The diet of this child can be described as massive malnutrition and has nothing to do with a healthy vegan diet. Almond milk can be consumed by children in small quantities in addition to healthy complementary foods (i.e. from about the 8th month), but it is anything but an adequate substitute for breast milk.

Infants are also NEVER vegan, as they depend on breast milk, which is known to be non-vegan but comes from a non-vegetable source.

It is understandable, therefore, if the child described suffered from developmental disorders. However, these were not due to the L-carnitine deficiency that was present at the same time, but to the fact that the child had received far too little food overall. It was literally starving and thus suffered from a lack of all nutrients and vital substances. The iodine deficiency, which alone can lead to the symptoms described, was particularly pronounced.

Such exceptional phenomena – which are usually gratefully picked up by the media – could be one of the reasons why people still believe today that vegan children are automatically malnourished. But that is not the case.

It is important for a healthy diet that all the necessary nutrients and vital substances are included. Then the organism can also produce sufficient L-carnitine itself:

Substances that the body needs to produce L-carnitine

To produce L-carnitine, the organism not only needs lysine and methionine but also vitamin C, vitamin B3 (niacin), vitamin B6 (pyridoxine), vitamin B12, folic acid, and iron.

So in a vegan diet – as in any other diet – it is important to ensure a reliable supply of all these nutrients and vital substances. If there are long-term shortages of one of these substances, this can of course also lead to an L-carnitine deficiency.

However, vitamin C, like folic acid, is not a problem in a vegan diet. On the contrary, both vitamins tend to be deficient in conventional nutrition, but not in vegan nutrition.

• Vitamin B3 is found in relevant amounts in brown rice, mushrooms, peanuts, sesame, and legumes.
• Vitamin B6 is found, for example, in soy products, legumes, walnuts, sunflower seeds, potatoes, carrots, Brussels sprouts, and bananas.

With a healthy vegan diet, all building materials for the self-synthesis of L-carnitine are available, so that there can be no L-carnitine deficiency.

The Oregon State University therefore also writes that strict vegetarians (= vegans) normally synthesize sufficient L-carnitine, so an L-carnitine deficiency does not occur more frequently here than in the normal eating population.

Just looking at the symptoms of an L-carnitine deficiency makes the claim that vegans are threatened by such a deficiency seem almost ridiculous:

L-carnitine deficiency – the symptoms

Deficiency symptoms that occur with an insufficient L-carnitine supply include:

• Weight gain up to obesity
• cardiovascular diseases
• high cholesterol
• diabetes
• Liver disorders up to liver cirrhosis
• Reduced performance, rapid fatigue, premature exhaustion

However, vegetarians and vegans in particular are known for almost never being overweight. The vegan diet has also been shown to be associated with a reduced risk of cardiovascular disease and diabetes. Vegans have consistently low cholesterol levels in every study. Also, nothing is known about the fact that vegans often suffer from liver diseases or from premature fatigue.

Who Needs L-Carnitine Supplementation?

A dietary supplement with L-carnitine is therefore not necessary for vegans. Of course, you can – if you want – take L-carnitine on a trial basis, for example, if you feel chronically tired or already suffer from a pre-diabetes stage, and observe whether your condition improves. But this applies to all people, regardless of their diet.

On the other hand, those who must take L-carnitine, in any case, are dialysis patients and other chronically ill people who receive L-carnitine from their doctor.

Cancer patients can also take L-carnitine to slow down the rapid weight loss that often occurs (3 x 1000 mg per day). It also reduces the side effects of chemotherapy because L-carnitine protects the heart muscle cells. It is best not to take L-carnitine in the evening, as it could wake you up.