Vitamins doses

Niacin action at pharmacological doses differs from effects at much lower vitamin doses. 

Vitamin An organie eompound present in variable, minute quantities in natural foodstuffs, and essential for the normal proeesses of growth and maintenanee of the body. Vitamins do not furnish energy, but are neeessary for energy transformation and for regulation of metabolism. 

Mathe, G. Red wine, green tea and vitamins do their antioxidants play a role in immunologic protection against cancer or even AIDS Biomed. Pharmacother., 53, 165-167, 1999. 

It s never too early to start taking a prenatal vitamin when attempting to conceive. If one makes you feel nauseated, keep trying others, as there is a large variety on the market. But be absolutely sure to take one that includes the maximum daily recommended dose of folic acid (important for helping prevent neural tube defects and spina bifida). Organic prenatal vitamins do exist. The main differences between these and more conventional vitamins is that they re vegetarian and include no filler, artificial color, or flavor. 

Japaa In Japanese Food Law, synthetic and naturally occurring additives are treated differently. The latter, in particular naturally occurring flavors and vitamins, do not require any special permission for use. The Japanese Ministry of Health and Welfare (MHW) is responsible for the approval of color additives which are outlined in a positive list of approved colors. MHW allows petitions for the addition of a new colorant to the list. Synthetic dyes permitted for food coloring in Japan include food dyes approved in the EU or/and in the USA (Table 5.7). 

The chemical structure of vitamin D3 is closely related to its precursor, 7-dehydrocholesterol, from which it is produced by a photochemical reaction. Therefore, vitamin Do is closely related structurally to the four-ring nucleus of steroids derived from the cyclopentanoperhydro-phenanthrene ring system. No vitamin D activity is noticed until the B ring of 7-dehydrocholesterol is opened between C-9 and C-10. Thus, vitamin D3 is a 9,10-seco steroid and its carbon skeleton is numbered accordingly (Scheme I). The important aspects of its chemistry center about the 5,6,7-cis-triene structure. The formula for vitamin D3 is C27H44O and its formula weight is 384.64. 

It was later discovered that vitamin D occurs in two active forms, ergocalciferol and cholecalciferol. Ergocal-ciferol is the synthetic form derived by the irradiation of ergosterol and is designated as vitamin (13,14). Cholecalciferol, the natural form, was identified (15,16) and designated as vitamin D3. Vitamins Do and °3 are equally active in humans and other mammals, Dut Dg is virtually inactive in poultry. 

Thin Layer Chromatography is used by major manufacturers of radiolabeled vitamin D3 (48) for monitoring purity. The systems described are 1) silica gel G with 10% acetone in hexane 2) silica gel G with acetone-hexane 1 1 and acetone-chloroform 1 1 3) silver nitrate-impregnated silica gel G with chloroform or chloroform-acetone 9 1 and 4) silica gel saturated with silicone oil using 4 1 acetone-water. It may be mentioned that these operations are carried out under very carefully controlled conditions to prevent or minimize decomposition. TLC is an excellent technique for separating vitamin Do from interfering materials, but it has to be used with due care in the quantita-... 

Rf Values of Vitamin Do on Silica Gel GF254 TLC Plates for Common Solvents... 

Circular Thin Layer Chromatographic Systems for Vitamin Do on Silica Gel D-0. Camag Without Binder... 

In recent years HPLC procedures have evolved as the methods of choice for the analysis of vitamin Do in bulk drug (32,33,53-61), pharmaceutical preparations (52-73), fortified milk (74-82), animal feed supplements (83-89), margarine (79), infant formulae (79), cod liver oil (90-93), and chicken egg (96). It may be pointed out that these reports represent the latest in the state-of-the-art in the HPLC analyses of vitamins Dg and D3. In spite of the intensive effort by a number of investigators and a few collaborative studies, there is no consensus on widely acceptable HPLC methods for vitamin D analysis in the bulk drug, pharmaceutical preparations, and fortified milk. 

Bulk vitamin Do may contain some of synthetic by-products shown in Scheme IV. Tartivita et al. (33) have reported an excellent chromatographic system which showed resolution of most of the photochemical isomers and reaction by-products. The chromatograms obtained on a 30-cm x 4-mm i.d. commercial microparticulate silica column using a 70 30 1 mixture of chloroform (free from ethanol and water), n-hexane, and tetrahydrofuran at a flow rate of 1 ml/min is shown in Figure 10. The detection was by a 254 nm UV detector. Using this system, vitamin D3 was quantitated in a resin sample containing 20 x 106 IU/g with a relative standard deviation of 1.37%. This procedure is essentially the basis for the USP XX (30) procedure for the analysis of bulk vitamin D3 which is reproduced below, in its entirety. 

Milk sold in the USA and Canada is required by law to be fortified with either vitamin Do or Do at the level of 400 IU/quart which is equivalent to 10 ng/mT... 

Major developments in the metabolic study came after selective JH and I7 C labeled vitamin Do with high specific activities were synthesized in the mid-1960 s. Since then, massive efforts by a number of investigators have led to the discovery of a large number of metabolities, the hormonal nature of the primary metabolities in the maintenance of... 

Lund and DeLuca (101) administered [ H] vitamin D3 to rats and found biologically active metabolites in the bone, liver and serum. The aqueous-soluble metabolites from the tissues and the feces did not have vitamin D activity. At least three biologically active metabolites were isolated from the chloroform-soluble portion of the extract. One of these was found in large amounts in the liver, blood and bone. In 1968, Blunt et. al. (102) proved convincingly that this major metabolite is 25-hydroxyvitamin D3 (25-OH-D3). Two other groups of investigators (103,104) independently found clues to the metabolic hydroxylation of vitamin Do. It was soon established that 25-hydroxylation of vitamin D3 takes place primarily in the liver (105,106) and that 25-0H-D3 is the major form of circulating vitamin D3 in human plasma (107). 

Abstract. Adsorption of antioxidants (vitamins C and E) from aqueous and ethanol solutions on unmodified and partially hydrophobized nanosilica A-200 was studied using UV spectroscopy and quantum chemical methods with consideration for the solvent effects. Antioxidant power of silica nanocomposites with immobilized vitamins was evaluated by measuring the total polyphenolic index following the Folin-Ciocalteu method. It has been shown that immobilization of vitamins on silica surface leads to their stabilization. Being released from the carrier molecules of vitamins do not lose their antioxidant properties... 

Lipids are derived from living systems of plants, animals, or humans. Substances that are lipids may also be called fat-soluble. For example, this designation is frequently applied to those vitamins in our food that a human can store in body fat. This is contrasted with the vitamins that are not lipid-like, but are instead water soluble. Excesses of the water soluble vitamins are passed in one s urine and must be replaced frequently. The fat-soluble, lipid-like vitamins do not need to be taken daily. (The common known fat-soluble vitamins are vitamins A, D, E, and K.)... 

An unfortunate effect of drinking too much alcohol—a hangover—is attributable to the acetaldehyde formed when ethanol is oxidized. There is some evidence that vitamin B j can cure a hangover. How can the vitamin do this ... 

Vitamins do not constitute any source of energy for the human body, nor are they considered to be structural material. But in cells and tissues, they have various... 

Conveniently coupled to a highly sensitive detection system since many vitamins do not contain useful chromophores. 

HPLC is now accepted as the method of choice for the analysis of the E vitamins (the tocopherols) from plant tissue extracts. However, difficulties in the extraction of the E vitamins do not always leave the samples in a convenient chromatographic buffer and consequently other methods of analysis have also been used (Desai, 1984). Vitamin E activity resides in a number of chemical species which are generally classified as tocopherols and tocotiienols. The most common forms are a-, /8-, y- and 5-tocopherols and separation of each can be performed using either normal phase or reversed phase chromatography. 

Vitamins are organic micronutrients that the body cannot produce in the amounts needed for good health. A number of vitamins have a high water solubility resulting from the highly polar nature of their molecules. All but one of the water-soluble vitamins are known to function as coenzymes in the body and are involved in many important metabolic processes. Fat-soluble vitamins have nonpolar molecular structures. As a result, they are insoluble in water but soluble in fat or other nonpolar solvents. Fat-soluble vitamins act somewhat like hormones in the body. Fat-soluble vitamins do not dissolve in water-based body fluids, so they are not excreted through the kidneys. Amounts in excess of bodily requirements are stored in body fat. Thus, it is much easier to produce toxic effects by overdosing with fat-soluble vitamins than with water-soluble vitamins. 

Pyridoxal, pyridoxamine and pyridoxine all show the typical reactions of an aromatic phenol unsubstituted fara to the phenolic group. In sufficient concentration they thus show reddish colors on addition of ferric chloride, couple with diazotized sulfanilic acid to yield orange to red-colored products, and with 2,6-dichloroquinone chlorimide to yield blue indophenols. The latter two reactions have been used for the quantitative estimation of vitamin Be imfortunately, other phenols occur in many products and the three forms of the vitamin do not, in general, yield equal color values. 

Beefsteak, lettuce, tomatoes, and beans never get to the cells and tissues of our bodies, including our brains. But the nutrient chemicals more than 40 of them, including amino acids, minerals, vitamins—do reach the body cells and tissues and are essential to their life. These are the ABCs of modern nutrition. 

Spices and herbs can play an important indirect role in good nutrition. They are not high in nutrient values, but they help to increase the appeal and satisfaction of foods that are highly nutritious. Spices do contain fat, protein and carbohydrates, electrolytic minerals, iron and B vitamins, and others, but even the highest calorie spice, poppy seeds, contains only two to three calories per serving in normal use (12). 

Sulfur Dioxide and Sulfites. Sulfur dioxide [7446-09-5], SO2, sodium bisulfite [15181-46-1], NaHSO, and sodium metabisulfite [23134-05-6] ate effective against molds, bacteria, and certain strains of yeast. The wine industry represents the largest user of sulfites, because the compounds do not affect the yeast needed for fermentation. Other appHcations include dehydrated fmits and vegetables, fmit juices, symps and concentrates, and fresh shrimp (79). Sulfites ate destmctive to thiamin, and cannot be used in foods, such as certain baked goods, that ate important sources of this vitamin. 

Reported cases of vitamin toxicity owing to overdose are usually associated with increased over-the-counter availabiHty of supplemental vitamins and indiscriminate supplementation. The misconception that if a Httle is good a lot is better has compounded toxicological problems with the vitamins. Eat-soluble vitamins tend to accumulate in the body with relatively inactive mechanism for excretion and cause greater toxicological difficulties than do water-soluble vitamins. 

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