Dietary supplements trace

Brewers and bakers dried yeasts are used as dietary supplements. They contribute some protein and trace minerals, and some B vitamins, but no vitamin C, vitamin B 2 or fat-soluble vitamins. The glucose tolerance factor (GTE) of yeast, chromium nicotinate, mediates the effect of insulin. It seems to be important for older persons who caimot synthesize GTE from inorganic dietary chromium. The ceU wall fraction of bakers yeast reduces cholesterol levels in rats fed a hypercholesteremic diet. 

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... 

Chromium is a trace mineral that is necessary to process carbohydrates and fats, as well as to help cells respond properly to insulin—an especially important function for people with diabetes. Chromium, in its safest form, can be found in whole grains, seafood, green beans, peanut butter, and potatoes. As a dietary supplement, chromium is available in several forms, including chromium picolinate, chromium chloride, chromium nicotinate, and high-chromium yeast. 

Zinc is an important trace element required for all healthy plants and animals. Zinc is found in proteins, such as meats, fish, eggs, and milk. About 10 to 15 miUigrams of zinc is required per day, and it may be taken as a dietary supplement. Zinc helps the blood in our bodies move the waste gas—carbon dioxide—to the lungs and helps prevent macular degeneration (loss of vision). 

The primary roles and the recommended daily intake of major and trace minerals are listed in Table 38-3. Similar to vitamins, these minerals are typically obtained from dietary sources. Specific minerals may likewise be included in various multivitamins and other dietary supplements, with the intent that these minerals will promote good health and prevent disease. Again, there is generally no need for mineral supplements for most people eating a reasonably balanced diet. On the other hand, mineral supplements can be helpful in specific situations where the body s need for a mineral may exceed dietary supply. Some examples of appropriate supplementation include calcium supplements for people with osteoporosis (see Chapter 31), potassium supplements for people on diuretics (see Chapter 21), and iron supplements for people with certain anemias. Hence, mineral supplements may be helpful in certain individuals, but the dose and type of supplement should be adjusted carefully. 

Cobalt is used in the manufacture of alloys and in nuclear technology. Cobalt compounds are also included in trace element supplement preparations for ruminants. The cobalt concentrations in vegetables and other foods have been found to be between < 0.01 and 0.83 mg/kg, while levels in milk are between 0.0002 and 0.06 mg/kg.40 Cobalt concentrations in dietary supplements ranged between <0.005 mg/kg to 4.1 mg/kg.26 The mean and 97.5th percentile dietary exposures to cobalt for adult consumers in 1994 were 0.11 mg/day and 0.019 mg/day respectively.10... 

Our interest in the role of trace elements in bone metabolism developed in a rather bizarre fashion. Ve became interested in the orthopedic problems of a prominent professional basketball player. Bill Walton. Several years ago he was plagued by frequent broken bones, pains in his joints and an inability to heal bone fractures. We hypothesized that he might be deficient in trace elements as a result of his very limited vegetarian diet. In cooperation with his physician, we were able to analyze Walton s serum. We found no detectable manganese (Mn). His serum concentrations of copper (Cu) and zinc (Zn) were below normal values. Dietary supplementation with trace elements and calcium (Ca) was begun. Over a period of several months his bones healed and he returned to professional basketball (1,2). In cooperation with several other orthopedic physicians, we analyzed serum from other patients with slow bone healing. Several of these patients also had abnormally low Zn, Cu and Mn levels. 

A number of the transition metals are essential trace elements for living organisms, so that one medical application of transition metal compounds is in the treatment of deficiency diseases. Particular examples are provided by preparations containing iron to treat anaemia and the use of dietary supplements containing cobalt in the form of vitamin B 2, shown as its cyanide derivative in 1.5. The reverse of this type of treatment involves the removal of excess metal ions from the body using com-... 

For the general population, ingestion is the primary exposure pathway sources include dietary supplements and various foods including seafood, meats, milk products, and grains. Trace amounts are found in drinking water. Selenium is not absorbed from shampoos. 

FDA reviewed the scientific evidence and recommendations of various scientific bodies, including the Institute of Medicine, National Academies of Science, an expert panel for the National Cholesterol Education Program, and the Advisory Committee on the Dietary Guidelines for Americans 2000. On July 9, 2003, the FDA issued a regulation requiring manufacturers to list trans fatty acids on the Nutrition Facts panel of the labels of foods and some dietary supplements. The new requirement will mean that manufacturers of most conventional foods and some dietary supplements will have to list in the Nutrition Facts panel the trans fat content of the product, in addition to the information about its overall fat content and saturated fat content. Dietary supplement manufacturers will need to list trans fat, as well as saturated fat and cholesterol, on the Supplement Facts panel when their products contain more than trace amounts (0.5 g) of trans fat. Examples of dietary supplements that may contain trans fat are energy and nutrition bars. 

For some trace elements, continued suboptimal dietary intake— in the presence of physiological, nutritional, or other metabolic stress— may eventually have a detrimental effect. Then additional dietary supplementation may have a health restorative effect. Such effects are most clearly demonstrated in experimental animals. Examples include the effects of boron in the presence of vitamin D depletion, or the need for increased vanadium when there is either an experimentally induced deficient or excess supply of dietary iodine. ... 

Many dietary supplements imlude essential trace elements. 

It is well established that selenium is an essential trace element and selenium dietary supplements are commonly available, especially in countries such as France and New Zealand, where soils are selenium deficient. The principal role of selenium in vivo is to prevent free-radical damage either through incorporation into radical scavengers, or indirectly through reduction of the byproducts of oxidative damage. 

Awareness of healthful constituents in foods that can exert a positive influence on health, by reducing risk from cancer, heart disease, arthritis, Alzheimer s disease, and others has also increased [6]. These include antioxidants, soluble fibers, trace elements, and anti-microbials. Much of the available information is anecdotal or from the non-peer reviewed literature, and awaits scientific research to catch up with observations from advocates of various types and sources of foods. Also, dietary supplements are expanding in the market place as the source of nutraceuticals in place of natural sources in foods, stimulating questions regarding their bioavailability and relative benefits. 

Research to determine the benefits of CLA for humans will present a unique challenge in the next few years. It will certainly require the improved and complementary methods of CLA and trans FA analysis to evaluate the biological effects of dietary supplements to determine the true effects of CLA in humans. In some studies the presence of CLA in human bodies and those produced by bacteria in the gut may need to take into consideration. The CLA research to date in humans has focused mainly on the effects of rl0,fl2-18 2 rather than on c9,t 1-18 2, the major CLA isomer present in the milk and meat of ruminants. This would appear to be due to the readily available source of commercial CLA preparations compared to pure c9,tl 1-18 2. Commercial CLA preparations consist of an equal mixture of t 0,c 2-18 2 and c9,rl 1-18 2. On the other hand, the rl0,cl2-18 2 isomer is generally present only in trace amounts in milk fats, while some ruminant fats may contain more of the CLA isomers. The true response, if any, of c9,fl 1-18 2 in humans remains to be determined. Several cohort studies have shown a significant reduction in risk factors associated with the consumption of diets high in dairy products and certain types of cancers but not with others. It remains to be seen if the benefits were due to c9,rl 1-18 2, other components in dairy products, or synergistic processes. Regardless of whether CIA s apparent benefits can be translated to humans, it is likely that CLA, as a model test object, will be used in the future in many more studies related to major maladies such as cancer, atherosclerosis, diabetes, etc. 

Maintenance of vitamin activity in the supplement is affected by temperature, humidity, addity/ alkalinity, oxygen, ultraviolet hght, the presence of some trace minerals (dietary supplements are usually combinations of vitamins, minerals and trace elements), physical factors such as hammer milling and the length of time the supplement is stored. For example, choline chloride can destroy other vitamins during storage. 

Many dietary supplements include essential trace elements. 

Most recently, we have pursued a program of research and development involving HPLC-DCP applications for Se analysis and speciation [50]. Se is an essential trace element in the human diet, and it falls within the jurisdiction of the FDA to routinely monitor levels of sele-nate and/or other selenium species or derivatives that may be present in commercial formulations or the natural diet. Unfortunately, there is insufficient data at the moment to conclude what levels and how often selenium (Se) species are to be found in our food supply. It was, in part, the purpose of this particular study to develop improved HPLC-element selective detection (ESD) approaches for Se species in man/animal dietary supplements. 

---