Other Vitamins

How the above described vitamins influence in vitro 3H-tryptophan nuclear receptor binding is not clear. Based upon the experiments with added dithiothreitol, it appears that some vitamins act on the sulfhydryl groups of the receptor, which become modified, which interferes with 3H-tryptophan binding. Reviews of reports by others indicate that certain vitamins can bind to hepatic nuclei. Examples include (1) 3H-a-tocopherol, which has been reported to become incorporated into isolated rat liver nuclei in a nonspecific manner by binding to chromatin nonhistone chromosomal protein,196 and (2) rat liver nuclei, which contain receptors for a folate-binding protein.197 As yet, it is not known whether others act similarly or not. Thus, whether competitive binding to nuclei between vitamins and tryptophan occurs is not known. 

Occupational contact dermatitis to vitamin K has been described (Jirasek and ScHWANK 1965), while allergic reactions to vitamin C and D have not been documented, in spite of their widespread use. 

The possibility of a relationship between vitamin E and the synthesis or utilization of ascorbic acid is of considerable interest. The elegant studies of Caputto and his colleagues (summarized by Caputto et al., 1961) on the inhibition of ascorbic acid synthesis by rat liver homogenates in the absence of tocopherol are illuminating, but they apparently lead to the conclusion that the phenomenon is one that occurs only in vitro. They were unable to find any evidence of a defect in synthesis in vivo, and ascorbic acid levels were not significantly different in vitamin E-deficient and normal animals. However, Cimino and Bemardini (1951) reported that a-tocophcrol raised ascorbic acid levels in rats and guinea pigs, especially in certain tissues, and ascorbic acid itself has been shown to be active in certain vitamin E deficiency states (Dam, 1957). 

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Polarography is appHed in the presence of other vitamins, eg, in multivitamin tablets, without separation. The polarography of flavins is reviewed in Reference 71. 

Vitamin C, or ascorbic acid, is surely the best known of all vitamins. It was the first vitamin to be discovered (1928), the first to be structurally characterized (1933), and the first to be synthesized in the laboratory (1933). Over 200 million pounds of vitamin C are now synthesized worldwide each year, more than the total amount of all other vitamins combined. In addition to its use as a vitamin supplement, vitamin C is used as a food preservative, a "flour improver" in bakeries, and. an animal food additive. 

Vitamin K. Figure 1 The vitamin K cycle, w indicates where warfarin or other vitamin K antagonist inhibit the cycle. 

Wernicke s syndrome is a serious consequence of alcoholism and thiamine (vitamin Bx) deficiency. Certain characteristic signs of this disease, notably ophtalmoplegia, nystagmus, and ataxia, respond rapidly to the administration of thiamine but to no other-vitamin. Wernicke s syndrome may be accompanied by an acute global confusional state that may also respond to thiamine. Left untreated, Wernicke s syndrome frequently leads to a chronic disorder in which learning and memory are strongly impaired. This so-called Korsakoff s psychosis is characterized by confabulation, and is less likely to be reversible once established. 

Globally, undernutrition is widespread, leading to impaired growth, defective immune systems, and reduced work capacity. By contrast, in developed countries, there is often excessive food consumption (especially of fat), leading to obesity and to the development of cardiovascular disease and some forms of cancer. Deficiencies of vitamin A, iron, and iodine pose major health concerns in many countries, and deficiencies of other vitamins and minerals are a major cause of iU health. In developed countries, nutrient deficiency is rare, though there are vulnerable sections of the population at risk. Intakes of minerals and vitamins that are adequate to prevent deficiency may be inadequate to promote optimum health and longevity. 

A TLC method was developed for the estimation of nieotinie aeid and nicotinamide (Fignre 10.7) in phatmacentical preparations containing other vitamins, enzymes, herbs, and drugs, etc. [16]. The percentage recoveries for nicotinic acid and nicotinamide were 100.1 + 1.9 and 100.2 1.5, respectively, with this system. Each alcohol extract of samples or standard was pnt on sihca gel TLC plates, which were developed with distilled water. Each silica gel spot visualized under UV lamp was collected and extracted with 0.1 mol/1 HCl. The optical density of each clear extract was measured at 262 run. 

Other vitamin D analogs available in the United States include paricalcitol (19-nor-l,25-dihydroxyvitamin D2, Zemplar by Abbott Laboratories, North Chicago, IL) and doxercalciferol (1 -a-hydroxyvitamin D2, Hectoral by Bone Care International, Middleton, WI). Alfacalcidiol (1-a-hydroxyvitamin D3) is only available outside the United States. Paricalcitol has less effect on vitamin D receptors in the intestines, decreasing the effects on... 

Factor IX Replacement Hemophilia B therapy may include recombinant (produced via transfection of mammalian cells with the human factor IX gene) or plasma-derived (concentrate from pooled plasma) factor IX (see Table 64-2). Guidelines for choosing the factor-concentrate formulation for hemophilia B are similar to the guidelines for hemophilia A. However, older-generation factor IX concentrates containing other vitamin K-dependent proteins (e.g., factors II, VII, and IX), called prothrombin complex concentrates (PCCs), have been associated with thrombogenic side effects. Consequently, these products are not first-line treatment for hemophilia B.11... 

There is no other vitamin which exemplifies the interdependence between the human race and microorganisms better than Vitamin B12. Mankind still relies for its very existence upon the capability of a few species of bacteria to synthesize this fascinating coordination complex. A concerted effort is being made in a number of laboratories to determine procedures for the chemical synthesis of this vitamin. However, even the most talented synthetic chemists would have to admit that the organic chemist s lament is applicable to Vitamin B12 ... 

Some effects of irradiation on vitamins have been mentioned earlier. It appears that irradiation and heat treatment affect vitamins differendy. Apparendy, vitamins Br B6, B12 and folic acid decompose less under as high a radiation dose as 60 kGy than under autoclaving at 120°Cfor 20 minutes. On the other hand, vitamin C is much more sensitive to irradiation. Generally, the radiosensitive vitamins are also sensitive to light, heat, and oxygen. In fresh foods, the vitamins that are most susceptible to irradiation are A and E. There is also some decomposition of vitamins B, and C. Other vitamins are fairly stable under irradiation. However, for the most part, the vitamins are more susecptible to heat treatment than to irradiation. 

Calcitriol and tacalcitol are other vitamin D derivatives that have been studied for treatment of psoriasis. 

The nervous system is the most sensitive target for cyanide toxicity, partly because of its high metabolic demands. High doses of cyanide can result in death via central nervous system effects, which can cause respiratory arrest. In humans, chronic low-level cyanide exposure through cassava consumption (and possibly through tobacco smoke inhalation) has been associated with tropical neuropathy, tobacco amblyopia, and Leber s hereditary optic atrophy. It has been suggested that defects in the metabolic conversion of cyanide to thiocyanate, as well as nutritional deficiencies of protein and vitamin B12 and other vitamins and minerals may play a role in the development of these disorders (Wilson 1965). 

A number of dietary deficiencies may increase the risk of deleterious cyanide effects. Iodine deficiency is involved in the etiology of such thyroid disorders as goiter and cretinism. These disorders may be exacerbated by excess exposure to cyanide (Delange and Ermans 1971 Ermans et al. 1972). Protein deficiencies and vitamin B12, riboflavin and other vitamins and elemental deficiencies may subject people... 

Pantothenic acid and biotin were thus found to be growth factors for yeast. Like riboflavin these molecules are incorporated into larger molecules in order to exert their essential metabolic function. Unlike the other vitamins there has been no evidence of pathological signs in man which can be attributed to dietary deficiencies in biotin or pantothenic acid. 

Compared with other vitamins, the chemical structures of both folic acid and B12 are complex. They are prosthetic groups for the enzymes that catalyse the transfer of the methyl group (-CH3) between compounds (one-carbon metabolism). The -CH3 group is chemically unreactive, so that the chemistry for the transfers is difficult, requiring complex structures for catalysis. 

Analysis of vitamin content of food materials appears to be a developing field. B vitamins in rice were analyzed using a mobile phase which contained pentanesulfonic acid and heptanesulfonic acid (558). Although the peaks were not sharp, the separation of the vitamins was satisfactory. Vitamin D in fortified milk has b n analyzed after removal Of cholesterol and carotenes in a preliminary cleanup (559, 540). Vitamin A has been analyzed in margarine, infant formula, and fortified milk (541, 542). Reports of the analysis of other vitamins in food are few to te but this mode of analysis can be expected to rapidly expand in the future in light of the variety of vitamin determinations in formulations which have been done (see Section VIII,F,l). 

Medical personnel who work in affluent areas are unlikely to see large numbers of people with vitamin deficiency diseases. However, certain groups of the population are particularly at risk, such as low-income families and chronically ill patients. The classic symptoms of any vitamin deficiency disease as observed in laboratory animals are often blurred in humans. The clinical picture is often complicated by deficiencies of other vitamins, minerals, calories, and protein and by infections and parasite infestations, which usually accompany longstanding malnutrition. Biochemical, physiological, and behavioral changes can occur in the marginal deficiency state without or before the appearance of more specific symptoms. Since the nonspecificity of these changes makes them difficult to detail, this section focuses on the symptoms associated with individual vitamin deficiency diseases. 

Contraindications Hypercalcemia, malabsorption syndrome, vitamin D toxicity, hypersensitivity to other vitamin D products or analogs... 

Potatoes are an excellent source of carbohydrates and contain significant amounts ofphosphorus, potassium, calcium, and vitamins, especially vitamin C. Potato protein content, at over 10%, is relatively close to that of wheat flour (11%) also, thanks to their lysine, methionine, cystine and cysteine contents, potatoes are a valuable supplement to cereal proteins. For instance, potatoes provide a significant source of proteins (10-15% of total requirements), a major source of vitamin C, an important source of energy, and also minerals like iron and other vitamins such as thiamin, nicotinic acid, riboflavin, and pro-vitamin A (p carotene) (Salunkhe and Kadam, 1991). 

Vitamin K (along with other vitamins available) 0.66 mg OD-BD... 

Preparations of iron alone or in combination with vitamin folic acid or other vitamins are available (see table 6.2.1). 

Deficiency symptoms Deficiency of panthothenic acid is unlikely in man because of its widespread distribution in food, though it has been administered by mouth as a nutritional supplement as the calcium salt and usually in conjunction with other vitamins of the B group. 

Replenish other vitamin stores with folate, B-complex, and multivitamin supplements. 

Patients with nephrotic syndrome can lose vitamin D metabolites in the urine, presumably by loss of the vitamin D-binding protein. Such patients may have very low 25(OH)D levels. Some of them develop bone disease. It is not yet clear what value vitamin D therapy has in such patients, because therapeutic trials with vitamin D (or any other vitamin D metabolite) have not yet been carried out. Because the problem is not related to vitamin D metabolism, one would not anticipate any advantage in using the more expensive vitamin D metabolites in place of vitamin D itself. 

Other vitamins—vitamin R6 and niacin—complement folic acid. Vitamin R6 deficiency apparently causes chromosome breaks by the same mechanism as folate deficiency.43 Niacin is... 

Unlike other vitamins, cholecalciferol (vitamin D3) can be formed from a steroid precursor, 7-dehydrocholesterol (6.7), by the skin when exposed to sunlight with sufficient exposure to the sun, no preformed vitamin D is required from the diet. 

Vitamin B12 deficiency normally results from indequate absorption rather than inadequate dietary intake. Pernicious anaemia is caused by vitamin B12 deficiency symptoms include anaemia, glossitis, fatigue and degeneration of the peripheral nervous system and hypersensitivity of the skin. The adult RDA and RNI for B12 are 2 and 1.5 figday- respectively. Unlike other vitamins, B12 is obtained exclusively from animal food sources, such as meat, fish, poultry, eggs, shellfish, milk, cheese and eggs. Vitamin B12 in these foods is protein-bound and released by the action of HC1 and pepsin in the stomach. 

Riboflavin deficiency is not associated with a major human disease, although it frequently accompanies other vitamin deficiencies. Deficiency symptoms include dermatitis, cheilosis (fissuring at the corners of the mouth), and glossitis (the tongue appearing smooth and purplish). 

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