Nutritional deficiencies/deprivation

Skeletal fluorosis can be defined as excessive deposition of fluoride in bone. This is a pathological condition that is by far the most important aspect of chronic exposure to elevated levels of fluoride, either by inhalation or by ingestion. The skeletal deformities may be associated with or accentuated by nutritional deficiencies or even malnutrition and hard manual work or, possibly, other conditions found in areas of long-term social and nutritional deprivation [6]. See, for instance Fig. 1 of [54]. The situation is specific also for populations consuming large volumes of water, such as athletes or people with certain medical conditions or... 

Iron deficiency anemia is commonly found in both affluent and economically deprived populations. In prevention of this nutritional deficiency disease, both increase in dietary iron and increase in the availability of this dietary iron for population groups at risk should be concurrently addressed. This is a problem for which the solution lies primarily not with the medical community but rather with the providers of food in agriculture and food industry. 

Menaquinones are synthesized by intestinal bacteria, but it is unclear how much they contribute to vitamin K nutrition, because they are extremely hydrophobic, and win only be absorbed from regions of the gastrointestinal tract where bUe salts are present - mainly the terminal Ueum. However, prolonged use of antibiotics can lead to vitamin K deficiency and the development of vitamin K-responsive hypoprothrombinemia (Section 5.4), as can dietary deprivation of phylloquinone. In vitro, menaquinones 2 to 6 have the same activity as phylloquinone as coenzyme for the solubilized liver microsomal vitamin K-dependent carboxylase (Section 5.3.1), whereas menaquinones with a side chain longer than seven have lower activity (Suttie, 1995). In extrahepatic tissues, the principal active vitamer is menaquinone-4 (Thijssen and Drittij-Reijnders, 1996 Thijssen et al., 1996). 

In animals, the production of CO2 from [ Cjpalmitate or octanoate is not consistendy affected by riboflavin deficiency, possibly as a result of increased activity of carnitine palmitoyl transferase, which is more a response to food deprivation than to riboflavin deficiency. However, the production of C02 from [ C] adipic acid is significandy reduced, and responds rapidly (with some overshoot) to repletion with the vitamin. It has been suggested that the abiUty to metabolize a test dose of [ Cjadipic acid may provide a sensitive means of investigating ribodavin nutritional status in human beings (Bates, 1989, 1990). 

In many animals, dietary deprivation of choline leads to liver dysfunction and growth retardation, and some patients maintained on choline-free total parenteral nutrition develop liver damage that resolves when choline is provided, suggesting that endogenous synthesis may be inadequate to meet requirements (Zeisel, 2000). There is inadequate information to permit the setting of reference intakes, but the Acceptable Intake for adults is 550 mg (for men) or 425 mg (for women) per day (Institute of Medicine, 1998). In experimental animals choline deficiency is exacerbated by deficiency of methionine, folic acid, or vitamin B12, which impairs the capacity for de novo synthesis. 

Supplementation with appropriate vitamins and the addition of sufficient protein generally resolve nutritionally based disorders. Severe corneal disease caused by prolonged vitamin A deprivation is typically more resistant to treatment.Topical treatment with lubricants or retinoic acid may be helpful in combating vitamin A deficiency. 

For iron, iodine, cobalt (as cobalamins), selenium, copper, and zinc there are clinical examples of reversible deficiency disease. For these elements there is enough known about their biochemical functions to explain their importance in human nutrition. For others, such as manganese, chromium, molybdenum, and vanadium, their importance remains to be fuUy accepted in clinical practice. Stfll other elements such as bromine, fluorine, cadmium, lead, strontium, lithium, and tin have been claimed by at least one investigator to be essential for one or more animal species as demonstrated by dietary deprivation studies. 

In contrast to GH, a single measurement of IGF-I is considered an accurate reflection of IGF-I production. Serum concentrations of IGF-I are influenced by age, degree of sexual maturation, and nutritional status. As mentioned previously, IGF-I concentrations are low in states of GH deficiency but also in patients with acute or chronic protein or caloric deprivation. 

Long-term regulation of acetyl-CoA carboxylase involves nutritional, hormonal (e.g., insulin, thyroxine), and other factors. In animals on high-carbohydrate diets, fat-free diets, choline deprivation, or vitamin B12 deprivation, the activity is enhanced. However, fasting, high intake of fat or of polyunsaturated fatty acids, and prolonged biotin deficiency leads to decreased activity. In diabetes, the enzyme activity is low, but insulin administration raises it to normal levels. 

The basics of nonpharmacologic approaches should address issues of adequate nutrition, sleep, exercise, and stress reduction. Sleep deprivation, high stress, and deficiencies in dietary essential amino acids, fatty acids, vitamins, and minerals may exacerbate mood episodes and result in poorer outcomes. Another effective treatment is to combine medications with adjunctive psychoeduca-tional programs, supportive counseling, insight-oriented psychother-... 

It had been reported earlier (Uthus and Nielsen 1990, Nielsen 1991) that vanadium-deficient nutrition of rats led to increased thyroid weights and thyroid bo-dyweight ratios, and decreased growth. These studies showed that stress factors which alter thyroid status or iodine metabolism also enhance the response to vanadium deprivation. Indeed, it is possible that vanadium is essential in the control not only of certain enzyme reactions but also thyroid metabolism. 

Apparently inconsistency of vanadium deprivation signs is related to the fact that vanadium metabolism is sensitive to changes in the composition of the diet (44). Perhaps diet composition affects the form of dietary vanadium. Vanadium has a rich and varied chemistry, especially in the (IV) and (V) state. The form of vanadium, usually an oxyanlon (i.e. VOa", V02" "), depends upon its concentration in, and pH of, the medium (45). Perhaps, one form is more readily available for absorption, or active in metabolism, than another. Thus, a diet that is relatively low in vanadium might be nutritionally either deficient or adequate depending on the form of the vanadium. 

Deprivation of nutritional compounds and induced metabolic defects. Tryptophane deficiency in the diet causes the rapid formation of a posterior subcapsular cataract (Buschke, 1943). The model has the disadvantage, however, that a concomittant corneal opacity is induced which prevents further lens observation. The corneal opacity disappears again when returning to normal chow, such that the deprivated diet and a normal chow have to be fed in intervals. 

Essential Fatty Acids. The higher unsaturated fatty acids are indispensable for the rat. Deprivation of these fatty acids results in loss of hair, disturbances of fluid balance, loss of reproductive faculty, and ultimately in death. Similar deficiency symptoms have not been observed in man, because the amounts required are so small (in the rat only 20 mg linoleic acid per day) and an absolutely fat-free diet is practically unknown. It is established, however, that man cannot synthesize the higher unsaturated fatty acids either. They should be particulary important in the nutrition of infants the adult organism has large reserves to draw on. 

The quality of the experimental evidence for nutritional essentiality varies widely for the ultratrace elements. The evidence for the essentiality of three elements, iodine, molybdenum and selenium, is substantial and noncontroversial specific biochemical functions have been defined for these elements. The nutritional importance of iodine and selenium are such that they have separate entries in this encyclopedia. Molybdenum, however, is given very little nutritional attention, apparently because a deficiency of this element has not been unequivocally identified in humans other than individuals nourished by total parenteral nutrition or with genetic defects causing disturbances in metabolic pathways involving this element. Specific biochemical functions have not been defined for the other 15 ultratrace elements listed above. Thus, their essentiality is based on circumstantial evidence, which most often is that a dietary deprivation in an animal model results in a suboptimal biological function that is preventable or reversible by an intake of physiological amounts of the element in question. Often the circumstantial evidence includes an identified essential function in a lower form of life, and biochemical actions consistent with a biological role or beneficial action in humans. The circumstantial evidence for essentiality is substantial for arsenic, boron, chromium, nickel, silicon, and vanadium. The evidence for essentiality for the... 

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