Vitamin indications

Vitamin Indication for treatment Active form Pharmaceutical forms Pharmacologic daily doses Recommended daily dietary allowances (National Academy OF Sciences 1980) ... 

The use of an indicator or marking substance, which is adsorbed on the column in a position in known relation to that of the colourless substance (e.g., Sudan III for isolation of Vitamin D upon alumina). 

Methanol, which elutes at 4.69 min, is included as a neutral species to indicate the electroosmotic flow. When using standard solutions of each vitamin, CZE peaks are found at 3.41 min, 4.69 min, 6.31 min, and 8.31 min. Examine the structures and p/Ca information in Figure 12.47, and determine the order in which the four B vitamins elute. 

Food process optimi2ation measurements may link a single chemical such as a vitamin, or a physical change such as viscosity, to process conditions and to consumer acceptance. Retention levels of ascorbic acid [50-81-7] C HgO, or thiamine can often be used as an indicator of process conditions (see... 

Epidemiologic studies in Japan indicate an increased risk of stomach cancer owing to consumption of broiled fish and meats (116). In the United States, stomach cancer incidence has steadily declined since the 1940s, whereas consumption of broiled food has increased (108). In addition, the average human intake of PAHs is only 0.002 of that required to produce cancer in half of animals fed. Test results are often contradictory (117) and many components of food, such as vitamin A, unsaturated fatty acids, thiols, nitrites, and even saUva itself, tend to inhibit the mutagenic activity of PAHs (118—120). Therefore, the significance of PAHs in the human diet remains unknown (121,109). 

Physiological functions as well as clinical symptoms that occur in humans deficient in specific vitamins are given in Table 6. It is becoming more authenticated that vitamins have additional potential health benefits when adrninistered, via the diet or by supplementation, at levels above those required for obviating deficiency. Although for most vitamins the optimal levels are not yet estabUshed, some of the potential health benefits to be derived from vitamins are indicated (16). In one case, the level of scientific proof is such that the U.S. FDA has allowed "a health cl aim that women who are capable of... 

Along with increasing evidence of health benefits from consumption of vitamins at levels much higher than RE) A recommendations comes concern over potential toxicity. This topic has been reviewed (19). Like all chemical substances, a toxic level does exist for each vitarnin. Traditionally it has been assumed that all water-soluble vitamins are safe at any level of intake and all fat-soluble vitamins are toxic, especially at intakes more than 10 times the recommended allowances. These assumptions are now known to be incorrect. Very high doses of some water-soluble vitamins, especially niacin and vitamin B, are associated with adverse effects. In contrast, evidence indicates that some fat-soluble micronutrients, especially vitamin E, are safe at doses many times higher than recommended levels of intake. Chronic intakes above the RDA for vitamins A and D especially are to be avoided, however. 

Preparation of the vitamins in commercial quantities can involve isolation, chemical synthesis, fermentation, and mixed processes, including chemical and fermentation steps. The choice of process is economic, dictated by the need to obtain materials meeting specifications at the lowest cost. Current process technologies (ca 1997) employed for each vitamin are indicated in Table 9. 

It is generally assumed that adequate vitamin levels in humans can be obtained through a balanced diet. However, ongoing studies continue to indicate that the majority of the U.S. population is not receiving even the RDA through diet. Supplementary vitamins are thus provided for fortification of foods (20) and as oral or parenteral dosage forms. 

The most recent RDA has included a vitamin C recommendation of 100 mg/day for cigarette smokers. An increasing number of investigators have concluded that the current RDA for vitamin C may not be adequate for elderly individuals. Plasma vitamin C level is generally accepted as an indicator of vitamin C status. 

A recent study recommended that the current RDA be increased from 60 mg/d to 200 mg. The researchers indicated, however, that vitamin C daily doses above 400 mg have no value (163). 

Shipping vitamin D in crystalline or resin form should be done in containers marked appropriately to indicate the material is toxic by DOT standards. Its proper DOT labeling is DOT Hazard Class 6.1, poisonous. Waste material should be burned or placed in an appropriate landfill. 

Vitamin D withdrawal is an obvious treatment for D toxicity (219). However, because of the 5—7 d half-life of plasma vitamin D and 20—30 d half-life of 25-hydroxy vitamin D, it may not be immediately successful. A prompt reduction in dietary calcium is also indicated to reduce hypercalcemia. Sodium phytate can aid in reducing intestinal calcium transport. Calcitonin glucagon and glucocorticoid therapy have also been reported to reduce semm calcium resulting from D intoxication (210). 

Specifications and standards for various vitamin E forms and preparations for use in pharmaceutical appHcations ate given in the United States Pharmacopeia (52). AH products should contain not less than 96.0% or more than 102.0% of the appropriate form. The products must be labeled to indicate both the chemical and stereochemical forms contained in the product. 

Equations 4-8 illustrate some mild methods that can be used to cleave amides. Equations 4 and 5 indicate the conditions that were used by Woodward and Eschenmoser, respectively, in their synthesis of vitamin B,2- Butyl nitrite," nitrosyl chloride, and nitrosoniurn tetrafluoroborate... 

Equations 1-10 illustrate some mild methods that can be used to cleave amides. Equations 1 and 2 indicate the conditions that were used by Woodward and Eschenmoser, respectively, in their synthesis of vitamin B12. Butyl nitrite, nitrosyl chloride, and nitrosonium tetrafluoroborate (NO BF4 ) have also been used to cleave amides. Since only tertiary amides are cleaved by potassium -butoxide (eq. 3), this method can be used to effect selective cleavage of tertiary amides in the presence of primary or secondary amides.(Esters, however, are cleaved by similar conditions.) Photolytic cleavage of nitro amides (eq. 4) is discussed in a review. 

The ultraviolet spectrum of vitamin Be, or pyridoxine, measured in aqueous ethanol varies with the composition of the solvent indicating that this compound is in equilibrium with the zwitterion form 38. The equilibrium constant in pure water was obtained by extrapolation. Prior to this, equilibria which involved tautomers of type 39 had been suggested for vitamin Be, but see Section VI,A. In the case of pyridoxal, an additional equilibrium, 40 41, occurs (cf. Section VIII) other pyridoxal analogs have also been studied (Table II). 

Niacin is one of foe vitamin B vitamins (B3). Estimate foe approximate values of foe indicated bond angles. Its skeleton (not its Lewis structure) is given below. 

When funicular myelitis occurs in advanced stages of vitamin B12 deficiency, patients are given 250 pg vitamin B12/d during the first 2 weeks of treatment to alleviate the symptoms and to replenish the stores. If the deficiency has been caused by disturbed vitamin B12 absoiption, lifelong monthly injections of 100 pg vitamin B12 are indicated [2]. 

Binding calcium ions (Ca2+) is a prerequisite for the activation of seven clotting factors in the coagulation cascade that are dependent on vitamin K. The term cascade indicates, that the factois involved depend from... 

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

In bone, three proteins have been described which are vitamin K-dependent, osteocalcin (bone Gla protein), matrix Gla protein (MGP), and protein S. Osteocalcin is synthetized by osteoclasts, regulated by the active form of vitamin D, calcitriol. Its capacity to bind calcium needs a vitamin K-dependent y-carboxylation of three glutamic acid residues. The calcium binding capacity of osteocalcin indicates a possible role in bone mineralization, but its exact function is still unclear. However, it is widely used as a serum marker for bone mineralization. Protein S, mainly a coagulant, is also vitamin-K dependent and synthesized in the liver. Children with... 

DOSS itself is used as a laxative and cermumenolytic drug [71]. It is included in over-the-counter hematinic vitamin and mineral preparations to counteract the constipating effect of the iron contained in these products. In combination with anthrachinones, widespread use as catharic and emollient laxative is indicated [71-75]. 

Anand et al. 1987). The authors hypothesized that the ocular effects associated with endosulfan may be a result of prolonged hypertension (although no data on blood pressure were presented, and there is no other information to indicate that chronically administered endosulfan induces hypertension) or an endosulfan-induced vitamin A deficiency (which was observed in this study). Although the rabbit may represent a uniquely sensitive species, the possibility that long-term exposure of persons at hazardous waste sites to endosulfan may result in adverse effects on ocular tissues cannot be eliminated. 

Particular attention is given to the development of new mechanistic biomarker assays and bioassays that can be used as indices of the toxicity of mixtures. These biomarker assays are typically based on toxic mechanisms such as brain acetylcholinesterase inhibition, vitamin K antagonism, thyroxin antagonism, Ah-receptor-mediated toxicity, and interaction with the estrogenic receptor. They can give integrative measures of the toxicity of mixtures of compounds where the components of the mixture share the same mode of action. They can also give evidence of potentiation as well as additive toxicity. 

At first glance it may seem that like dissolves like does not apply here. Certainly, none of these complex molecules looks like water, and the resemblance to simple hydrocarbons such as cyclohexane also is remote. Keep in mind, however, that the basis for the principle is that similar compounds dissolve in each other because they have common patterns of intermolecular interactions. Example indicates that alcohols containing large nonpolar segments do not dissolve well in water. We can categorize vitamins similarly by the amounts of their stmctures that can be stabilized by hydrogen bonding to water molecules. 

With investigations of phytochemicals and functional foods, the outcome measure is generally going to be a biomarker of disease, such as serum cholesterol level as a marker of heart disease risk, or indicators of bone turnover as markers of osteoporosis risk. Alternatively, markers of exposure may also indicate the benefit from a functional food by demonstrating bioavailability, such as increased serum levels of vitamins or carotenoids. Some components will be measurable in both ways. For instance, effects of a folic acid-fortified food could be measured via decrease in plasma homocysteine levels, or increase in red blood cell folate. 

Nutrient analysis of stabilized rice bran and its derivatives indicates that it is a good source of protein, dietary fiber and carbohydrates, in addition to several valuable phytonutrients, antioxidants, vitamins and minerals (Table 17.1). SRB and its water-soluble and water-insoluble derivatives contain all the nutrients at different levels. They are gluten and lactose free and do not give rise to any food allergy. 

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