Amino Acids - Part II

As previously published in my Part I article, amino acids are grouped in two (2):

Part I which constitute Amino Acids derived from diet http://hubpages.com/hub/Amino_Acids_-_Part_I

Part II which are manufactured by the liver

The 80% or so others that are manufactured by the liver, and which are classed as "nonessential" amino acids are:

• alanine, arginine, asparagine, aspartic acid, citrulline, cysteine, cystine, gamma-aminobutyric acid, glutamic, acid, glutamine, glycine, ornithine, proline, serine, taurine, tyrosine

The functioning of amino acids are interrelated, and a balanced and steady supply of these nutrients are needed to maintain proper body functioning. A dietary shortage of amino acids can impact negatively on your health - just as other stressors, such as trauma, drug use, age, infections etc. When the body synthesizes protein, ammonia is formed in the liver as a waste product, and too large amounts of protein into the diet can result in too much ammonia being formed, and in so doing placing extra stress on the liver and kidneys to flush it out the body. Amino acid supplements come in various forms but can essentially be divided in three types of products - either derived from animal protein, yeast or vegetable protein. Most amino acids can be produced in two forms, except for glycine, that is either a D or L form. These letters stands for the way in which the amino acid spiral is wound up - D is for the right wound type and L for the mirror left winding amino acid. Human amino acid is the L type and for this reason many people prefer to use supplements containing the L type amino acid.

Amino acid supplementation information

Free form amino acids are the ones immediately absorbed into the body and need no digestion at all.When taking an amino acid supplement it is best to have vitamin c (ascorbic acid) as well as vitamin B6 present at the same time for best absorption. But like all things, use it as prescribed, and with common sense, as very high doses of aspartic acid, glutamic acid, homocysteine, serine and tryptophan could form toxic levels in the body, and in so doing cause damage.

Alanine is a non-essential amino acid and is used by the body to build protein and was first isolated in 1879. The alpha-carbon in alanine is substituted with a levorotatory (l)-methyl group, making it one of the simplest amino acids with respect to molecular structure and is one of the most widely used in protein construction.

Alanine is required for

It is required for the metabolism of glucose and tryptophan and beta-alanine is a constituent of vitamin B5 (pantothenic acid) as well as coenzyme A. It has also demonstrated a cholesterol-reducing effect in rats.

People suffering from Epstein Barr (also sometimes referred to as glandular fever) as well as chronic fatigue syndrome, have been linked to excessively high levels of alanine while having low levels of tyrosine and phenylalanine.

Deficiency of alanine

None known.

Dosage

Dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Most people do not need to supplement with alanine since it is well provided for in the diet, and can be synthesized from pyruvic acid (formed in the breakdown of carbohydrates).

Toxicity and symptoms of high intake

Alanine does not have many side effects, but people with kidney or liver disease should not consume high intakes of amino acids without consulting a health care professional.

When more may be required

People on a very low protein diet, could be at risk of a deficiency.

Other interesting points

It has been found that alanine is present in prostate fluid, and it may play a role in the role of the prostate. In one study of men with benign prostatic hyperplasia, it was found that 780 mg of alanine per day for two weeks and then 390 mg for the next two and a half months, taken together in combination with equal amounts of glycine and glutamic acid reduced the symptoms.

Food sources of alanine

As with the other amino acids, excellent sources of alanine include meat, poultry, fish, eggs, and

Arginine is a non-essential amino acid and is abundant in protamines and histones - both proteins associated with nucleic acids and was first isolated in 1895 from animal horn. Newborns may produce this amino acid too slowly and for them arginine should be seen as an essential amino acid.

Arginine required for

It is extremely useful in enhancing the immune system, and it increases the size and activity of the thymus gland, which is responsible for manufacturing T lymphocytes - the much talked about T-cells, which assist the immune system. For this reason it might be an important nutrient for people suffering from AIDS and other malignant diseases which suppress the immune system.

In the pancreas it is used to release insulin and in the pituitary gland it is a component of human growth hormone, and is used in sexual stimulants, as people report longer and more intense orgasms when their intake of arginine is increased.

It is also important in liver health and assists in neutralizing ammonia in the liver, while it is also involved in the skin and connective tissue - making it important in healing and repair of tissue as well as the formation of collagen and building of new bone and tendons.

Arginine is found in seminal fluid and L-arginine is used in the treatment of male sexual health and has been used in the treatment of sterility.

It is required in muscle metabolism - maintaining the nitrogen balance, and helping with weight control since it facilitates the increase of muscle mass, while reducing body fat.

Deficiency of arginine

Rare - but signs may include impaired insulin production as well as possible hair loss.

Dosage

Dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Toxicity and symptoms of high intake

Rare, but symptoms of massive dosages may include skin thickening and coarsening of the skin, weakness, diarrhea, nausea, as well as increasing the activity of some viruses. For this reason people suffering from herpes should avoid high dosage. Pregnant and lactating women and people suffering from schizophrenia should also avoid high dosage.

Other interesting points

Arginine pyroglutamate, in addition to having cognitive enhancing effects, is an excellent growth hormone releaser because it is carried more efficiently across the blood-brain barrier than arginine alone. In Italy, this form of amino acid is used to treat senility, mental retardation, and alcoholism. Arginine pyroglutamate is an arginine molecule combined with a pyroglutamate molecule. Arginine alone does not produce cognitive enhancing effects.

This nutrient is gaining popularity as a non-prescription treatment for high cholesterol as animal studies and preliminary studies in humans suggest that it may improve coronary blood flow and lower cholesterol levels with its antioxidant property, and helping to keep blood-vessel tissue elastic.

Food sources of arginine

Whole-wheat, nuts, seeds, peanuts, brown rice, popcorn, soy, raisins, chocolate, carob.

Asparagine is a non-essential amino acid and is closely related to aspartic acid, and can be manufactured from this nutrient and was first isolated in 1932 from asparagus and is also widely available in plant protein, but a great volume of information is not available.

Asparagine is required for

It is required by the nervous system to maintain equilibrium and is also required for amino acid transformation from one form to the other which is achieved in the liver.

Deficiency of asparagine

None known.

Dosage

Dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Toxicity and symptoms of high intake

Not reported.

Food sources of asparagine

It is found in dairy, beef, poultry and eggs.

Carnitine is really not an amino acid, but because of the close structural sameness, it is normally classed with amino acids, and is also known as vitamin BT. It is available as D-carnitine, L-carnitine, DL-carnitine as well as acetyl-L-carnitine, but with L-carnitine being the most popular type. L-Carnitine is synthesized from the essential amino acids lysine and methionine, but enough vitamin B1 (thiamine) and B6 (pyridoxine) must be available.

Carnitine required for

Unlike a true amino acid, it is not used in protein synthesis nor as neurotransmitter, but is used for long-chain fatty acid transport and is required for entry of these long-chain fatty acids into the mitochondria of the cell, as well as for the removal of short-chain organic acids from the mitochondria, which frees the intra-mitochondrial coenzyme.

It is therefore important for the energy supply within the cell, as well as muscles, assists in preventing fatty build-up in areas such as the heart, liver, and skeletal muscles.

It may also reduce the risk of poor fat metabolism in diabetes, alcohol-induced fatty liver as well as the risk of heart problems. Carnitine has also been shown to improve the antioxidant effect of vitamin C as well as E.

Deficiency of carnitine

Primarily, carnitine deficiency occurs because of a genetic defect preventing carnitine transport and a deficiency may result in confusion, heart pain, muscular weakness as well as obesity.

Dosage

Dosages listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Since carnitine can be manufactured in the body, supplementation of carnitine is not essential.

Most infant formulas that do not contain carnitine and could be supplemented with carnitine to the levels found in human milk, 11.3 mg/L (70 mmol/L) - but consult your medical professional regarding this matter.

Men normally require more carnitine than women, because of heavier body mass.

Toxicity and symptoms of high intake

None known but supplements in excess of 3,000 mg (19 mmol) of carnitine per day may cause diarrhea and/or "fish odor" syndrome.

When more may be required

Because of more muscle mass, men normally require more carnitine.

Other interesting points

Carnitine may have functions in cellular metabolism such as plasma membrane fatty acid remodeling, gene regulation and modulation of cytokine concentrations in experimental sepsis and cancer cachexia.

Esters of carnitine (acetyl- and propionylcarnitine) may have pharmacological value, by virtue of their antioxidant properties and/or ability to deliver readily oxidizable carbon units to mitochondria, in chronic disorders such as Alzheimer's disease and ischemia-induced myocardial dysfunction in angina pectoris.

The long-term administration of acetyl-L-carnitine to aged rats restores a synaptic pattern comparable to that of young rats. With the exception of the tocopherols all the antioxidants had lower concentrations in the Substantia nigra, which showed the most severe neuronal depletion with age. Acetyl-L-carnitine is being investigated as a determinant of neuronal longevity.

Acetyl-L-carnitine (ALCAR), is regarded with interest because of its capacity to counteract several physiological and pathological modifications typical of brain aging processes. In particular, it has been demonstrated that ALCAR can counteract the age-dependent reduction of several receptors in the central nervous system of rodents, such as the NMDA receptor system, the Nerve Growth Factor (NGF) receptors, those of glucocorticoids, neurotransmitters and others, thereby enhancing the efficiency of synaptic transmission, which is considerably slowed down by aging and appears to reverse age-associated deficits in cellular function, in part by increasing cellular ATP production.

Food sources

Carnitine is found in good amounts in red meat, while fish, chicken and milk are also high in carnitine, while vegetables and grains contain very little of this nutrient.

Citrulline is found in high concentration in the liver. Citrulline is not a component of any major proteins or enzymes, and therefore not much information is contained on this page.

Citrulline is required for

The amino acid citrulline is required to detoxify the liver from ammonia, which is a waste product of the body from oxidation.

Citrulline promotes energy and assists with the immune system. This unusual amino acid is formed in the urea cycle by the addition of carbon dioxide and ammonia to ornithine.

It is then combined with aspartic acid to form arginosuccinic acid, which later is metabolized into the amino acid arginine.

Dosage

Dosages listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind

Cysteine is a sulfur containing non-essential amino acid and is closely related to cystine, as cystine consists of two cysteine molecules joined together. It is an unstable nutrient and easily converts to cystine, but this does not cause a problem, since both can convert into the other - as required by the body.

Cysteine required for

Your skin, as well as detoxification of your body, requires cysteine. It is found in beta-keratin, the main protein in nails, skin as well as hair. It not only is important in collagen production but also assists in skin elasticity and texture.

Cysteine is also required in the manufacture of the amino acid taurine and is a component of the antioxidant gluthione. It is useful to detoxify the body from harmful toxins and help protect the brain and liver from damage from alcohol, drugs etc.

It has also been found that it may help in strengthening the protective lining of the stomach as well as intestines, which may help prevent damage caused by aspirin and similar drugs.

Cysteine is also critical to the metabolism of a number of essential biochemicals including coenzyme A, heparin, biotin, lipoid acid, and glutathione.

Deficiency of cysteine

No direct deficiencies have been reported as such.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

General dosage is not known but as supplement cysteine is used at 200 mg two to three times per day.

Toxicity and symptoms of high intake

None known, but damage to nerve cells in rats has been reported in very high dosage, and research data is still being waited upon.

People suffering from diabetes and cystinuria should be careful of cysteine supplements.

Best used with

Best taken with selenium vitamin B6 and vitamin E.

When more may be required

People suffering from AIDS/HIV may benefit from cysteine in proper amounts, as low levels are normally reported in people with this problem.

Food sources of cysteine

The body can synthesize cysteine from the amino acid methionine but is also found in high protein foods such as poultry, wheat, broccoli, eggs as well as garlic, onions and red peppers.

Cystine is a crystalline, sulfur-containing amino acid, formed from two molecules of the amino acid cysteine. It can be converted to cysteine by reduction and was discovered in 1810 but was not recognized as a component of proteins until 1899, when it was isolated from animal horn - it is particularly abundant in skeletal and connective tissues, hair and digestive enzymes.

The steps followed in the formation of cystine and cysteine, is from methionine to cystathionine and then to cysteine to cystine. For more information please see cysteine as well.

Cystine is required for

Required for proper vitamin B6 utilization and is also helpful in the healing of burns and wounds, breaking down mucus deposits in illnesses such as bronchitis as well as cystic fibrosis.

Cysteine also assists in the supply of insulin to the pancreas, which is needed for the assimilation of sugars and starches.

It increases the level of glutathione in the lungs, liver, kidneys and bone marrow, and this may have an anti-aging effect on the body by reducing age-spots etc.

It has been shown as a detoxification agent to protect the body against damage of alcohol and cigarette smoking, and may be effective in preventing hangovers, as well as preventing liver and brain damage.

Deficiency of cystine

In chronic diseases it appears that the formation of cysteine from methionine is prevented, resulting in a deficiency.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Toxicity and symptoms of high intake

People suffering from diabetes should be careful when taking supplementation, as it could inactivate insulin.

GABA stands for gamma-aminobutyric acid, is the product of a biochemical decarboxylation reaction of glutamic acid by the vitamin pyridoxal, as well as from decarboxylase (GAD).

GABA is required for

GABA is required as an inhibitory neurotransmitter to block the transmission of an impulse from one cell to another in the central nervous system, which prevents over-firing of the nerve cells.

It is also used for brain metabolism and to treat both epilepsy and hypertension where it is thought to induce tranquility in individuals who have a high activity of manic behavior and acute agitation.

In combination with inositol and nicotinamide it helps with blocking anxiety and stress related impulses from reaching the motor centers of the brain.

Gamma-Aminobutyric Acid can be used to calm a person, much like tranquilizers, but without the possibility of addiction.

Deficiency of GABA

It has been suggested that a shortage of GABA may cause panic attacks, since an intake of tranquilizers can increase the level of GABA in the body. GABA may also be effective in treating PMS in women.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Dosage has not been established, but it is interesting to note that some research suggests that the supplement Kava (kava is a herbal root used as a supplement) causes more GABA receptors to form in the brain.

Toxicity and symptoms of high intake

Toxic levels have not been established, but very high intake of GABA may cause anxiety, tingling of extremities, shortness of breath as well as a numb feeling around the mouth.

Other interesting points

It is sometimes used as sexual a stimulant because of its relaxing capabilities, as well as with prostate problems, since it also assists with the release of sex hormones.

Glutamic acid, a non-essential amino acid and is synthesized from a number of amino acids including ornithine and arginine.

Glutamic acid is required for

It is an important excitatory neurotransmitter, and glutamic acid is also important in the metabolism of sugars and fats.

It helps with the transportation of potassium across the blood-brain barrier, although itself does not pass this barrier that easily. It also shows promise in the future treatment of neurological conditions, ulcers, hypoglycemic come, muscular dystrophy, epilepsy, Parkinson's, and mental retardation.

Glutamic acid can be used as fuel in the brain, and can attach itself to nitrogen atoms in the process of forming glutamine, and this action also detoxifies the body of ammonia. This action is the only way in which the brain can be detoxified from ammonia.

The fluid produced by the prostate gland also contains amounts of glutamic acid, and may play a role in the normal function of the prostate.

Deficiency of glutamic acid

None known.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Toxicity and symptoms of high intake

High dosages of glutamic acid may include symptoms such as headaches and neurological problems.

Although no major side effects are reported on supplementation of this nutrient, people with kidney or liver disease should not consume high intakes of amino acids without first consulting a medical professional.

People suffering from personality disorders as well as child behavior disorders may find benefit from this nutrient.

Food sources of glutamic acid

Excellent sources of glutamic acid include meat, poultry, fish, eggs, and dairy products, as well as some protein-rich plant foods.

Glutamine is a non-essential amino acid and is found in large amounts in the muscles of the body, and since it easily pass through the blood-brain barrier, it is also known as a superb brain fuel, and some people refer to it as a "smart-vitamin" - although it is in actual fact no vitamin at all.

Glutamine is required for

It is converted to glutamic acid in the brain, which is essential for cerebral functions, and increases the amount of GABA (gamma-aminobutyric acid), which is required for brain functioning and mental activity.

It is used in the muscles for the synthesis of muscle proteins, and is of use for the treatment of wasting muscles after illness or post-operative care.

Although the body requires nitrogen, free nitrogen in the body can be harmful since it forms ammonia - especially toxic to the brain. The liver normally converts ammonia to urea, excreted in the urine - but glutamic acid attaches itself to nitrogen and forms glutamic acid, while removing ammonia from the brain.

It further is used in the body to balance the acid/alkaline level and is also the basis or building blocks of RNA and DNA.

It serves as a source of fuel for cells lining the intestines and it is also used by white blood cells and is important for immune function.

Deficiency of glutamine

Deficiency of this nutrient is rare, since it can be manufactured by the body but deficiencies can develop during periods of fasting, starvation, strict dieting, cirrhosis, and weight loss associated with AIDS and cancer.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

In the presence of good health, supplementation of glutamine should not be necessary.

Toxicity and symptoms of high intake

No clear toxicity has emerged in glutamine studies, but it should not be taken by people suffering from liver or kidney problems.

When more may be required

People suffering from arthritis, fibrosis, connective tissue disease, peptic ulcers, ulcerative colitis, as well as epilepsy, fatigue, impotence and senility may find benefit from an increase of this nutrient, as well as people busy with alcohol abuse withdrawal and patients living with HIV.

Other interesting points

Monosodium glutamate (MSG), a salt of glutamic acid, is sometimes used as a condiment for flavoring foods. It imparts no flavor of its own, but enhances the flavors of meats, fish, and vegetables. Some people have an allergic reaction to MSG, and should be avoided by such individuals.

L-glutamine supplements are also referred to as "smart drugs" since it is thought to improve the functioning of the brain.

In animal research, glutamine has anti-inflammatory effects. Glutamine also decreases the craving for sweets and sugar, which is beneficial to people wishing to lose weight.

Food sources

Glutamine is found in many high protein foods, such as fish, meat, beans, and dairy as well as in vegetables such as raw parsley and spinach.

Glycine is a sweet tasting, non-essential amino acid that was first isolated in 1820 from gelatin and is also found in good quantity in silk fibroin. This nonessential nutrient can be manufactured from serine and threonine, so dietary intake is not essential.

Glycine is required for

It is required to build protein in the body and synthesis of nucleic acids, the construction of RNA as well as DNA, bile acids and other amino acids in the body. It is further found to be useful in aiding the absorption of calcium in the body.

It helps in retarding degeneration of muscles since it helps to supply extra creatine in the body.

It is also found in fairly large amounts in the prostate fluid and may for this reason be important in prostate health.

The glycine amino acid is also used by the nervous system and its function as an inhibitory neurotransmitter makes it important to help prevent epileptic seizures and it is also used in the treatment of manic depression and hyperactivity.

Deficiency of glycine

Few people are glycine deficient, in part because the body makes its own supply of the non-essential amino acids, and because it is abundant in food sources.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Toxicity and symptoms of high intake

No clear toxicity has emerged from glycine studies, however individuals with kidney or liver disease should not consume high intakes of amino acids without consulting a health care professional.

When more may be required

In a study where men were given extra glycine over a period of time, it reduced the symptoms of prostatic hyperplasia.

Other interesting points

If the amino acid serine is required in the body, it can be converted from glycine.

Food sources of glycine

High protein food contains good amounts of glycine and is present in fish, meat, beans, and dairy products.

Ornithine is a non-essential amino acid and is manufactured by the body, the amino acid, arginine, is metabolized during urea production and is required by the body as it acts as a precursor of citrulline, proline and glutamic acid.

Ornithine is required for

Ornithine is important since it induce the release of growth hormone in the body, which in turn helps with fat metabolism. It is further required for a properly functioning immune system and liver and assists in ammonia detoxification and liver rejuvenation.

It is also of use in healing and repairing skin and tissue and is found in both these body parts. There are some unsupported claims that ornithine promotes muscle building, but this has not been proven.

Deficiency of ornithine

Since the body can produce ornithine, a deficiency of this non-essential amino acid is rare.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

In human research involving ornithine, several grams are typically used per day, sometimes combined with arginine.

Toxicity and symptoms of high intake

There are no reported side effects from the use of ornithine, but children, pregnant or nursing mothers, or anybody suffering from schizophrenia should NOT take L-ornithine.

Best used with

Arginine is needed for the production of ornithine and should be supplied in adequate quantities to the body. Carnitine also enhances the effect of this nutrient.

When more may be required

People recouping after surgery and athletes may benefit from this nutrient.

Food sources of ornithine

The body can manufacture ornithine but is abundant in protein foods such as meat, fish, dairy, and eggs.

Proline was first isolated from casein in 1901, and unlike any of the other amino acids it is readily soluble in alcohol. It is a nonessential amino acid and can be synthesized from glutamic acid and does not require dietary sources. As information is very limited on this nutrient, our page is also very short.

Proline is required for

Proline improves skin texture and aids collagen formation and helps contain the loss of collagen during aging. Collagen in the skin contains hydroxyproline and hydroxylysine, which is formed from proline and lysine, in which ascorbic acid seems to be important in this conversion. Collagen contains about 15 % proline. It is also thought to be important in the maintenance of muscles, joints and tendons.

Proline is best used with

According to the current information available it would be recommended that an ample supply of vitamin C (ascorbic acid) be present to maximize the efficiency of proline.

Food sources

Proline is mostly found in meat sources.

Serine was first isolated in 1865 from sericin, a silk protein, and is a nonessential amino acid and can be synthesized in the body from glycine.

Serine is required for

Serine is required for the metabolism of fat, tissue growth and the immune system as it assists in the production of immunoglobulins and antibodies. Some derivatives (e.g. ethanolamine) are also important components of the phospholipids found in biological membranes.

It is a constituent of brain proteins and nerve coverings and is also important in the formation of cell membranes, involved in the metabolism of purines and pyrimidines, and muscle synthesis. It is also used in cosmetics as a skin moisturizer.

Toxicity and symptoms of high intake

Although toxicity has not been established it has been found that very elevated serine levels may cause immune suppression and psychological symptoms as in cerebral allergies.

Best used with

Its production requires adequate amounts of B3 (niacin), B-6, and Folic acid.

Food sources of serine

It is found in meats and dairy products, wheat gluten, peanuts as well as soy products.

Taurine is a non-essential amino acid and is found in high concentrations in the white blood cells, skeletal muscles, central nervous system as well as the heart muscles. In adults, but not children, this nutrient can be manufactured from methionine in the body and from cysteine in the liver, but vitamin B6 must be present.

Taurine required for

It is a key ingredient of bile, which in turn is needed for fat digestion, absorption of fat-soluble vitamins as well as the control of cholesterol serum levels in the body. (It is incorporated in the bile acid chenodeoxychloic acid, which emulsify the dietary fats) This nutrient is also used in the proper use of potassium, calcium as well as sodium in the body, and for maintaining cell membrane integrity. It is thought to be helpful with anxiety, hyperactivity, poor brain function and epilepsy as well as hydrating the brain. Taurine, together with zinc is also required for proper eye health and vision.

Deficiency of taurine

A deficiency may impair vision and problems with fat metabolism may appear, and a theory exists that it may also be involved in epilepsy developing.

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

No dosage has been established, but people who take supplements normally take 2 grams, three times per day.

Toxicity and symptoms of high intake

No toxicity has been determined and most people would not require a supplement and even small children derive enough of it through human milk, or infant formulas.

Best used with

Vitamin B6 is required by the body to synthesize this nutrient from other nutrients.

When more taurine may be required

Vegans who consume no eggs or dairy products ingest virtually no taurine through their diets, but normally have enough since the body can manufacture the requirements. Children with Down's syndrome may benefit from taurine, and women being treated for breast cancer as well as people with metabolic disorders, since metabolic disorders can cause loss of this nutrient via urine. Diabetics may also benefit from this nutrient, since this disease increase the need for this nutrient.

Enemy of taurine

High intake of alcohol may cause the body not to be able to use it fully.

Food sources

Taurine is mostly found in meat and fish, and the adult body can manufacture it.

Tyrosine was first isolated from casein in 1849 and is abundant in insulin as well as the enzyme papain and can be synthesized from the amino acid phenylalanine in the body.

It is a precursor of the neurotransmitters epinephrine, norepinephrine and dopamine, all of them extremely important in the brain and transmits nerve impulses and prevents depression. Dopamine is also vital to mental function and seems to play a role in sex drive

Tyrosine required for

The action of this amino acid in brain functions is clear with its link to dopamine as well as norepinephrine, but it is also helpful in suppressing the appetite and reducing body fat, production of skin and hair pigment, the proper functioning of the thyroid as well as the pituitary and adrenal gland.

It is used for stress reduction and may be beneficial in narcolepsy, fatigue, anxiety, depression, allergies, headaches as well as drug withdrawal. In a study, using soldiers, tyrosine proved effective in alleviating stress and keeping them more alert.

Deficiency of nutrient

Tyrosine, a parent amino acid for skin, hair, and eye pigments and is involved in syndromes, known generally as oculocutaneous albinism, that are characterized by the failure to form melanin pigments, resulting in partial or complete albinism.

It is also the precursor amino acid for the thyroid gland hormone thyroxin, and a defect in this may result in hypothyroidism - an enlargement of the thyroid gland (goiter), severe growth failure, and retardation of central nervous system development.

A deficiency may also have symptoms of low blood pressure, low body temperature (including cold hands and feet) and "restless leg syndrome".

Dosage

The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.

Dosage levels are not confirmed but some experiments have been performed with people taking up to 5 - 7 grams per day, with no confirmed toxic levels, but people taking MAO inhibitors, who suffer from high blood pressure and have problems with skin cancer should not take supplementation of L-tyrosine, and should aim to limit their intake of food sources high in this nutrient.

Best used with

If taking a tyrosine supplement it is best to take it at bedtime, or with a high carbohydrate meal to prevent competition of absorption with other amino acids. Folic acid, copper and vitamin B6 is a good combination to have with this nutrient to maximize absorption and effectiveness.

Other interesting points

Tyrosine and tryptophan have with been used with some success in the treatment of cocaine abuse and in another study it was combined with the antidepressant Imipramine to treat chronic cocaine abuse where it was reported that the combination blocked the cocaine high and prevented the severe depression that accompanies withdrawal.

Food sources of tyrosine

Meat, dairy, eggs as well as almonds, avocados and bananas are good sources of this nutrient.