Alanine plays an important role in the regulation of insulin secretion.

• can regulate blood sugar levels
• helps with urea cycle disorders
• supports the immune system
• supports muscle tissue building

Recommendations:
To our knowledge, there is no information regarding daily doses of alanine supplementation.

Dietary sources:
meat, hard-boiled eggs, salmon, avocado, sunflower seeds, full-fat milk, yogurt, gelatin, almonds.

Arginine is synthesised from glutamine, glutamate and proline. The body is usually able to meet the demand for this compound.

• plays an important role in the metabolism and function of many organs
• acts as an antioxidant, supports the immune system, regulates the secretion of growth hormone and insulin, and detoxifies ammonia
• is the main building block of proteins
• improves cardiovascular function, neurological function, wound healing, male and female fertility, nutrient absorption
• regulates glycaemia, helps fight obesity, lowers blood pressure, may inhibit the development of atherosclerosis, supports the fight against infections
• improves pancreatic function

Recommendations:
The recommended daily dose of arginine should be between 3 and 8 grams. To make the most of the properties of arginine, it is recommended to take it up to 2 hours before planned physical activity or before going to sleep.

Dietary sources:
pumpkin seeds, sesame seeds, walnuts, almonds, pine nuts, poultry, pork, beef, soybeans, seaweed, chickpeas, peanuts.

Asparagine can be synthesised from oxaloacetate (a metabolic intermediate compound that is involved in gluconeogenesis, the urea cycle, the glyoxylate cycle, amino acid synthesis, fatty acid synthesis, and the citric acid cycle).

• supports immune function
• supports the nervous system
• helps to increase the volume of muscle mass
• stores ammonia in tissues (detoxification)

Recommendations:
Asparagine doses should be taken in the same amount each day - the most common recommendation is to take the substance twice a day. Usually, 1.5 to 6 grams of the supplement are taken - usually before planned physical activity and before sleep.

Dietary sources:
dairy, poultry, eggs, fish, beef, whey, legumes, potatoes, whole grains, nuts, soya, seeds, asparagus, seafood

Beta-alanine is a non-protein amino acid produced endogenously in the liver.

• together with histidine is involved in the synthesis of carnosine in skeletal muscle
• it reduces muscle acidity during intense exercise (improves exercise performance)
• it has anti-ageing, antioxidant, and immune-boosting properties

Recommendations:
The standard daily dose is 2-5 g. Taking larger amounts than recommended may cause tingling sensations on the skin, especially on the face, neck, and hands. Beta-alanine supplementation appears to be a reasonable strategy for improving the performance of high-intensity exercise. Supplementation is particularly recommended for vegetarians.

Dietary sources:
poultry, fish

Cittruline is an endogenous amino acid that, due to its properties, helps to regulate blood pressure and increase muscle endurance.

• plays an important role in the body, including in the urea cycle (removal of harmful compounds)
• it may help dilate blood vessels by producing nitric oxide, which relaxes cells
• it may enhance physical exercise performance
• it is helpful as a potential therapeutic agent in cerebrovascular diseases such as cerebral ischaemia
• together with arginine it may prevent skin ageing, improve wound and bone healing

Recommendations:
Citrulline is generally considered safe for supplementation, but there is no information on optimal doses of L-citrulline. Pregnant and breastfeeding women should not supplement it.

Dietary sources:
watermelon, pumpkin, melon, calabash, cucumber

Phenylalanine is one of the 20 DNA-encoded amino acids that form the basic building blocks of most naturally occurring proteins.

• it plays a key role in the biosynthesis of other amino acids and is important for the functioning of many proteins and enzymes
• is crucial in the production of the neurotransmitters dopamine, noradrenaline and adrenaline
• dermatologists use this amino acid as a therapeutic tool in the treatment of acquired vitiligo
• has antidepressant effects in patients with unipolar depression
• can stimulate fat oxidation throughout the body (fat burning)

Recommendations:
According to the World Health Organisation (WHO) and the Food and Agriculture Organisation of the United Nations (FAO), the basic level of phenylalanine and tyrosine required for health is 14 mg/kg body weight per day.

Dietary sources:
beef, fish, poultry, yoghurt, milk, cheese, pork, eggs, nuts, soy products, artificial sweeteners

Glycine is essential for the synthesis of proteins such as collagen and the biosynthesis of haem, creatine, glutathione, and purines. It belongs to the group of 20 essential amino acids. The human body cannot synthesise enough glycine to meet its metabolic requirements.

• is involved in the transmission of chemical signals in the brain
• plays an important role in the proper functioning of certain enzymes, the digestion and absorption of lipids
• helps build muscle tissue

Recommendations:
The average adult needs almost 15 grams of glycine per day. Glycine deficiency is not life-threatening, but chronic deficiency can increase oxidative stress levels and the risk of bone and joint disease. Oral glycine supplementation can be very effective in reducing some metabolic disorders in people with cardiovascular disease, various inflammatory conditions, cancer, diabetes, and obesity. Some studies report that low-dose glycine supplementation can improve sleep quality and facilitate learning.

Dietary sources:
pumpkin seeds, sunflower seeds, nuts, meat, fish, natural yoghurt, cheese, rice, buckwheat groats, red lentils, oatmeal, wheat bran, raspberries, cauliflower, spinach

Belongs to the group of 20 canonical amino acids. Almost all protein-containing products contain glutamine.

• supports the immune system
• supports the regeneration of the intestines, which reduces their permeability to toxins and pathogens
• may accelerate muscle recovery after intensive exercise and thus reduce muscle pain

Recommendations:
Glutamine supplementation reduces the incidence of infections, inflammation, and improves the functioning of the intestinal barrier and immune system. A typical diet should contain 3-6 grams of glutamine/day.

Dietary sources:
spinach, beef, fish, dairy, cabbage, eggs, beetroot, Brussels sprouts, beans, chicken, vegetable juices, celery, parsley, carrots

Belongs to the group of 20 canonical amino acids. The adult body can synthesise sufficient amounts of this compound. However, supplementation may be necessary for adolescents growing up.

• is involved in the production of hormones and metabolites that affect kidney function, reduce oxidative stress, are involved in nerve conduction
• helps protect nerve cells
• is a precursor of carnosine
• is a precursor of histamine released from immune cells during an allergic reaction

Recommendations:
Histidine supplementation is considered safe for most people, except for pregnant women and lactating mothers. Potential benefits of histidine supplementation in obese women with metabolic syndrome include a reduction in insulin resistance and body fat. According to the World Health Organisation (WHO) and the Food and Agriculture Organisation of the United Nations (FAO), the baseline level of histidine required for human health is 10 mg/kg of body weight.

Dietary sources:
soy, fish, meat, eggs, beans, nuts, whole grain products

Homoarginine is a cationic amino acid that is formed from lysine and found in the kidney and liver. In vivo and in vitro, it shows properties similar to arginine. Homoarginine is a useful predictor of cardiovascular events and associated mortality. A direct correlation between homoarginine levels and kidney function, as well as the progression of chronic kidney disease (CKD) has been confirmed. Low homoarginine levels may be an early indicator of renal failure.

• risk marker for cardiovascular disease, cerebrovascular disease, and kidney disease

Recommendations:
There are studies supporting an increased risk of stroke at low homoarginine levels.

Dietary sources:
legumes

Isoleucine is one of the branched-chain amino acids, along with valine and leucine. It belongs to the group of 20 canonical amino acids. It plays an important role in human life, affecting stress, energy and muscle metabolism. It is an exogenous amino acid.

• contributes to the muscle mass growth
• reduces muscle soreness after training and fatigue from exertion
• may improve both mental and physical performance
• is involved in the synthesis of glutamine and alanine

Recommendations:
According to the World Health Organisation (WHO) and the Food and Agriculture Organisation of the United Nations (FAO), the baseline level of isoleucine is 20 mg/kg body weight. Supplementation with branched-chain amino acids may help reduce symptoms of neurological diseases (such as depression, anxiety, amyotrophic lateral sclerosis). Isoleucine deficiency manifests as muscle cramps.

Dietary sources:
fish, meat, eggs, nuts, legumes, seeds

The requirement for aspartate in the human body is met entirely by biosynthesis, so it is an endogenous amino acid.

• is used to increase muscle strength, improve sports performance, and reduce fatigue
• helps in the production of antibodies and immunoglobins
• regulates the menstrual cycle and promotes ovulation in women
• potentially protects the brain, liver, and central nervous system by removing ammonia from the body

Recommendations:
The daily dose of aspartic acid is typically between 1.5 and 6 g. It can be taken approximately 2 hours before training or immediately after waking up. Some manufacturers recommend taking it before bedtime as well.

Dietary sources:
fish, chicken, oysters, peanuts, avocados, lentils, asparagus

Gamma-aminobutyric acid is an organic chemical compound from the amino acid group that is the most common inhibitory neurotransmitter in central nervous system.

• is the main inhibitory neurotransmitter in the central nervous system
• facilitates communication between brain cells
• can reduce stress, relieve pain, and facilitate sleep
• researchers have found that brown rice extract containing high levels of GABA can prevent chronic alcohol-related diseases

Recommendations:
Studies have shown that a high dose of GABA (0.8 g/kg) can reduce the number of seizures in patients with epilepsy. At the same time, too high a concentration of this amino acid may cause adverse effects such as increased anxiety, numbness, tingling, and shortness of breath.

Dietary sources:
bananas, brown rice, beef, lentils, oats, broccoli, potato, fish, tomato, shrimp, spinach, almonds, walnuts, sunflower seeds, citrus fruits

Glutamic acid belongs to the group of 20 canonical amino acids. It is an endogenous amino acid. In the body, it is converted to glutamine by L-glutamine synthetase.

• belongs to the main group of neurotransmitters - in the brain improves brain function and mental activity. Furthermore, it detoxifies the brain from ammonia and helps transport potassium across the blood-brain barrier
• supports muscles
• supports the immune system
• has anti-cancer properties
• it is likely to be used in the future to treat neurological conditions, ulcers, hypoglycaemic coma, muscular dystrophy, epilepsy, Parkinson's disease, and intellectual disability.

Recommendations:
Symptoms of glutamic acid deficiency include lethargy, fatigue, insomnia, and difficulty concentrating. These symptoms are characteristic of excessive accumulation of ammonia.

Dietary sources:
eggs, poultry, fish, sesame, cottonseed, country cheese

Leucine is one of the branched-chain amino acids, together with valine and isoleucine. It belongs to the group of 20 canonical amino acids and plays an important role in human life, influencing stress, energy, and muscle metabolism. It is an exogenous amino acid.

• contributes to the muscle mass growth
• reduces muscle soreness after training and fatigue from exertion
• may improve both mental and physical performance
• is a flavour enhancer

Recommendations:
According to the World Health Organisation (WHO) and the Food and Agriculture Organisation of the United Nations (FAO), the baseline level of leucine is 39 mg/kg body weight. Leucine supplementation can help in liver regeneration and may also be helpful in treating patients with phenylketonuria. Branched-chain amino acid supplementation can help reduce symptoms of neurological diseases (such as depression, anxiety and amyotrophic lateral sclerosis).

Dietary sources:
brown rice, beans, meat, nuts, soya, whole-grain flour

Belongs to the group of 20 canonical amino acids. Lysine cannot be synthesized in the body, so it must be obtained from a balanced diet or supplements.

• is particularly important for the immune system as it plays a key role in the formation of antibodies
• protects against herpes simplex virus (HSV)
• may improve symptom severity and cognitive deficits in patients with schizophrenia
• may increase calcium absorption
• lysine supplementation has been shown to reduce chronic anxiety
• plays an important role in maintaining bone health
• enhances the absorption of iron and zinc ions
• some studies suggest that lysine supplementation may reduce the risk of stroke

Recommendations:
According to the World Health Organisation (WHO) and the Food and Agriculture Organisation of the United Nations (FAO), the baseline level of lysine required for health is 30 mg/kg body weight. Lysine deficiency can cause fatigue, weakness, eye redness, dizziness, decreased concentration, anaemia, and enzymopathy.

Dietary sources:
red meat

Belongs to the group of 20 canonical amino acids. Methionine is an essential amino acid for normal growth and development of the body.

• plays an important role in the immune system
• glutathione, a product of L-methionine metabolism, has antiviral effects
• some studies show a positive effect of L-methionine in the treatment of immunodeficiency
• has a crucial in the production of several proteins and hormones, including carnitine and adrenaline

Recommendations:
According to the World Health Organisation (WHO) and the Food and Agriculture Organisation of the United Nations (FAO), the baseline level of methionine is 10 mg/kg body weight.

Dietary sources:
sesame, beef, chicken breast fillet, soy, raw salmon, sprouts, spinach

L-ornithine is an amino acid that is not part of proteins. It is synthesized from arginine (urea cycle) and is a key compound in the production of proline, glutamic acid, and citrulline.

• helps to remove ammonia from the liver, especially in patients with encephalopathy (elevated blood ammonia levels)
• promotes muscle mass growth and improves athletic performance by stimulating the secretion of growth hormone
• prevents fatigue
• L-ornithine together with α-ketoglutarate helps the skin to recover from injuries, e.g., burns
• has a relaxing effect and improves the quality of sleep

Recommendations:
Ornithine supplementation is recommended during illness, high stress, and poor well-being. The healthy body produces the necessary amounts of this compound on its own. Excessive consumption of ornithine can cause diarrhoea and stomach cramps.

Dietary sources:
fish, meat, dairy products, nuts, soya, rice, wheat

Proline is one of the 20 basic amino acids. It is used in the production of collagen. Proline can be endogenously synthesized from glutamate or ornithine.

• delays the aging process and improves skin condition
• accelerates wound and burn healing
• strengthens arterial walls and protects the endothelial layer, may have anti-atherosclerotic effects
• improves intestinal health
• supports brain function
• reduces stress

Recommendations:
Proline deficiency is extremely rare. Long-distance runners or individuals participating in prolonged exercise may have a higher demand for this amino acid. It is also important during rehabilitation period after injury. The recommended dose of proline supplementation has not been determined.

Dietary sources:
lamb, cream, beef, liver, eggs, poultry, cottage cheese, fish.

Taurine is an organic chemical compound from the group of biogenic amino acids and is the end product of the degradation of the sulfur amino acid cysteine.

• is a neurotransmitter
• stabilises cell membranes
• is involved in the transport of sodium, potassium, calcium, and magnesium ions
• affects the transport of creatine into muscles
• accelerates muscle recovery after exercise

Recommendations:
Taurine supplementation may be beneficial in the prevention of atherosclerosis and ischaemic heart disease. Taurine increases the excretion of bilirubin and cholesterol in the bile, which is important for the proper functioning of the gallbladder. This amino acid may also reduce the symptoms of many diseases, including the central nervous system, cardiovascular system, and musculoskeletal system. The recommended dose of taurine supplementation is from 0.5 to 2 grams. The maximum daily dose of taurine is 3 grams. The supplement should be taken between meals.

Dietary sources:
shellfish, meat, milk, energy drinks

This is a non-protein amino acid that occurs as an intermediate in the synthesis and degradation of the amino acid glycine.

• has a positive effect on the treatment of depression, anxiety disorders, memory loss, mood disorders
• supports the therapy of individuals with psychotic disorders, schizophrenia, Parkinson's disease, and ADHD
• helps maintain concentration and improves perceptiveness
• is a promising biomarker for prostate cancer

Recommendations:
There is a lack of information on safe and effective daily doses of sarcosine for supplementation. Patients with elevated levels of sarcosine may experience loss of appetite, vomiting, delayed growth, hypertension, hypoactivity, cardiomyopathy, irritability, muscle tremors, and impaired mental ability.

Dietary sources:
eggs, turkey, pork, vegetables, legumes

Is an endogenous protein amino acid formed from 3-phosphoglycerate and is a precursor of glycine and cysteine. It belongs to the group of 20 essential amino acids.

• plays an important role in the normal functioning of the central nervous system
• is involved in the synthesis of nucleotides
• is involved in protein and lipid metabolism
• reduces the level of cortisol, known as the stress hormone
• supports the immune system.

Recommendations:
Deficiencies are rare and usually result from malnutrition, anaemia or severe illness. They manifest as a worsening mood, chronic lack of energy and can aggravate depressive states.

Dietary sources:
soya, nuts, eggs, meat, lentils, fish, chickpeas

L-threonine is one of the 20 essential protein amino acids. It belongs to the exogenous amino acids and must be supplied with food.

• supports the immune system by participating in antibody production
• participates in the formation of collagen and elastin
• supports fat metabolism in the liver
• has a positive effect on the thyroid gland function
• regulates digestion, forms a layer of mucus covering the digestive tract
• influences bone health and strengthens tooth enamel
• reduces stress and nervous tension

Recommendations:
Vegetarians and vegans belong to a group that may have lower levels of threonine in the body and should consider supplementation. According to the World Health Organisation (WHO) and the Food and Agriculture Organisation of the United Nations (FAO), the baseline level of threonine required for human health is 15 mg/kg body weight.

Dietary sources:
salmon, mackerel, halibut, eggs, meat, milk, dairy products, sardines, soy, lentils, soy products, chickpeas, hazelnuts, almonds, walnuts, bread, wheat germ, Brussels sprouts, cabbage, bananas, pineapples, papaya, spinach, asparagus

L-tryptofan is one of the 20 essential amino acids that make up proteins. It is an exogenous amino acid and is essential for normal growth.

• is the biochemical precursor of serotonin (neurotransmitter), melatonin (hormone), niacin (vitamin B3)
• essential for the proper functioning of the nervous system - reduces hyperactivity and tension
• helps to maintain intestinal homeostasis and regulates metabolism
• supports immune functions
• improves mood and sleep quality
• is responsible for the production of kynurenin which is a chemical UV filter in the eye

Recommendations:
Tryptophan supplementation is considered safe. The recommended dose is 500 mg per day, taken in the evening.

Dietary sources:
chicken breast fillet, eggs, raw salmon, pork, oats, cashew nuts, pumpkin seeds, sesame, tofu, milk, soy, brown rice, chocolate

Tyrosine is one of the 20 basic protein amino acids. It belongs to the endogenous amino acids, which the body synthesizes from phenylalanine. It is involved in the production of thyroid hormones, dopamine, adrenaline, noradrenaline, and melanin.

• participates in the synthesis of neurotransmitters and hormones
• is essential for the proper functioning of the thyroid and pituitary gland
• deficiency can lead to depression
• improves concentration and the ability to remember and learn
• reduces fatigue
• increases resilience to stress
• regulates blood pressure

Recommendations:
The recommended dose is 100 mg/kg of body weight, but the maximum daily dose of 10 g should not be exceeded. The best effects are achieved when taken occasionally, for a specific purpose (e.g., to quickly improve learning performance or increase physical endurance). The highest concentration of tyrosine in the blood is observed within the first two hours after ingestion. The state of increased concentration and good mood lasts for a maximum of 8 hours.

Dietary sources:
beef, pork, fish, tofu, chicken, milk, cheese, beans, seeds, nuts, whole grain products.

Valine is one of the branched-chain amino acids, along with leucine and isoleucine. It belongs to the group of 20 canonical amino acids. It plays an important role in increasing resistance to stress, muscle energy and metabolism. It is one of the essential amino acids.

• supports muscle growth
• reduces muscle soreness and fatigue after exercise
• may improve both mental and physical performance
• is involved in the synthesis of glutamine and alanine
• supports the immune system, influences hair conditio, and skin pigmentation
• has a protective effect on the nervous system

Recommendations:
According to the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO), the baseline level of valine is 26 mg/kg body weight. Supplementation with branched-chain amino acids may help reduce symptoms of neurological diseases (such as depression, anxiety, and amyotrophic lateral sclerosis). Valine deficiency leads to insomnia, concentration disorders, muscle tremors, touch sensitivity, lack of appetite, weight loss, and anaemia. Symptoms of excess valine may include hypoglycaemia, kidney and liver dysfunction, hallucinations, delusions, and skin tingling.

Dietary sources:
dairy products, fish, meat, lentils, mushrooms, sesame seeds, leafy vegetables, soy, peanuts.