Dietary supplements amino acids

L-tryptophan is a naturally-produced, natural amino acid used as a dietary supplement. Samples from one manufacturer were found to be contaminated by trace amounts of another naturally occurring compound — l,l -ethylidene bis-[i.-tryptophan]. The latter compound appears to have been responsible for causing a number of deaths and additional cases of chronic eosinophilia-myalgia,111 some of which might have been prevented had there... 

A newer therapeutic approach is the administration of betaine (6-12 g daily), which lowers homocysteine levels by favoring remethylation [33], A theoretical hazard of betaine treatment is increasing the blood methionine, sometimes to an extravagant degree ( 1 mmol/1). Experience to date indicates that betaine administration is safe, with no major side effects except for a fishy odor to the urine. Other therapeutic approaches have included the administration of salicylate to ameliorate the thromboembolic diathesis. Patients also have been treated with dietary supplements of L-cystine, since the block of the transsulfura-tion pathway in theory could diminish the synthesis of this amino acid. 

While the dog is a carnivore, it is able to adapt to an omnivorous diet. Requirements for dietary sources of energy, amino acids, glucose precursors, fatty acids, minerals, vitamins, and water have been established based on recommendations by the National Research Council (NRC, 1985). Adult beagles maintained in a laboratory environment function well with one feeding of standard laboratory chow per day. In safety assessment testing, however, some compounds may induce serious dietary deficiencies through induced loss of appetite, malabsorption, or vomiting, and, in these cases, it may be advisable to provide a dietary supplement. 

In 1989, the amino acid dietary supplement L-tryptophan was thought to he associated with an outbreak of eosinophila-myalgia syndrome (EMS), a condition characterized by an increase in white blood cell count, severe muscle pain, and other skin and neuromuscular problems. Later studies showed that an impurity present during the manufacture of the amino acid was probably responsible for the outbreak of EMS and that the amino acid itself was probably safe for human consumption. 

Li, P., Kim, S. W., Datta, S., Pond, W. G., and Wu, G. (2008). Dietary supplementation with cholesterol and docosahexanoic acid affects concentrations of amino acids in tissues of young pigs. Nitric Oxide 19, 259-265. 

Treatment of this rare, autosomal recessive disorder involves a diet low in these amino acids as well as dietary supplementation with keto acids and thiamine. 

A dietary supplement is any product taken by mouth that contains a so-called dietary ingredient and whose label clearly states that it is a dietary supplement. The dietary ingredients in dietary supplements may include vitamins, minerals, herbs, and amino acids as well as substances such as enzymes, organ tissues, metabolites, extracts, or concentrates. Dietary supplements can be... 

Dietary supplements are products taken by mouth that contain an ingredient intended to supplement the diet, such as vitamins, minerals, herbs or other botanicals, amino acids, and substances such as enzymes, organ tissues, and metabolites. Dietary supplements come in many forms, including extracts, concentrates, tablets, capsules, gel caps, liquids, and powders. They have special requirements for labeling. In the U.S., the Dietary Supplement Health and Education Act of 1994 states that dietary supplements are considered foods, not drugs. (Note that some dietary supplements are used in conventional medicine for example, folic acid... 

Vitamins and minerals, whose main dietary sources are other than fruits and vegetables, are also likely to play a significant role in the prevention and repair of DNA damage, and thus are important to the maintenance of long-term health. Vitamin B12 is found in animal products, and deficiencies of B12 cause a functional folate deficiency, accumulation of the amino acid homocysteine (a risk factor for heart disease),46 and chromosome breaks. B12 supplementation above the RDA was necessary to minimize chromosome breakage.47 Strict vegetarians are at increased risk for developing vitamin B12 deficiency. 

There is much interest in the pharmacological role of dietary nutrients in human health. Some nutrients have been recognized to have a hepatoprotective effect through interaction with TNF-a. For instance, dietary supplementation (5%, at the exp ense of casein) with glycine (30), a non-essential amino acid, attenuated LPS-induced liver injury and... 

Choline participates m normal fat metabolism and interrelates with methionine in a biochemical manipulation referred to as transmethylation. Choline, when in adequate quantity, cun replace the essential amino acid methionine when the latter is in limited quantity nr the reverse may wear, that is. methionine can be dismantled to replace choline. Choline delicienctes result in numerous degradalive physiologic changes in livestock. The usual dietary supplements are choline biianrale and choline chloride. 

Since animals tend to concentrate in their own proteins the sulfur amino acids contained in the plants diey eat, such animal products (meat. eggs, and cheese) are valuable sources of the essential sulfur amino acids in human diets. In regions where die diet is composed almost entirely of foods of plant origin, deficiencies of sulfur amino acids may be critical in human nutrition. Frequently, persons in such areas (also voluntary vegetarians) are also likely to suffer from a number of odier dietary insufficiencies unless supplemental sources are used. 

United States Congress passes Dietary Supplement Health and Education Act, which expressly defines a dietary supplement as a vitamin, a mineral, an herb or other botanical, an amino acid, or any other dietary substance. This law prohibits claims that herbs can treat diseases or disorders, but it allows more general health claims about the effect of herbs on the structure or function of the body or about the well-being they induce. Under this law, the FDA bears the burden of having to prove an herbal is unsafe before restricting its use. This law also establishes the Office of Dietary Supplements within the National Institutes of Health to promote and compile research on dietary supplements. 

In addition to unadulterated creatine monohydrate, special formulations of the supplement are available in the U.S. market which may include supplemental phosphates, amino acids, carbohydrates, and other dietary additives. There have also been laboratory reports of creatine that has been altered during the manufacturing process with other unlabeled and potentially harmful substances. 

Some creatine products currently on the market are also enriched with other nutrients, including protein, glucose, vitamins, herbal ingredients, and other amino acids. Again, no hard data exists on the effectiveness of taking creatine in combination with other dietary supplements or herbals. 

It may also be necessary to determine the free fatty acid content of oily materials as an index of rancidity, since this will affect palatability. Analyses of amino acids can only be conducted in specialized laboratories and are conducted less frequently. Instead most feed mixers (including commercial feed manufacturers) use procedures such as prediction equations based on the protein content of the sample to predict the content of important amino acids. Tests for minerals are more routine and are offered by most laboratories. Tests for vitamins are offered by certain laboratories but are not very frequent since commercial feed manufacturers often disregard any vitamin contribution from the dietary ingredients and add all the necessary vitamins in the form of a supplement. 

Acylcamitines or amino acids may also be important in disease monitoring and treatment or as markers for new therapies, toxicities, etc. In one application using dried plasma spots, carnitine and acylcamitines may be useful in detecting possible carnitine deficiency as a result of kidney dialysis for patients with end-stage renal disease (36,37). A deficiency should result in carnitine supplementation in those patients that cannot replenish their levels fast enough. In fact, this is one of the first pharmaceutical-related applications of screening. The measurement of certain amino acids such as Phe and Tyr and their ratio is also routinely performed to monitor the effectiveness of dietary intervention in patients with PKU. 

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