Vitamin, individual pantothenic acid

An Estimated Average Requirement (EAR) is the average daily nutrient intake level estimated to meet the requirements of half of the healthy individuals in a group. EARs have not been established for vitamin K, pantothenic acid, biotin, choline, chromium, fluoride, manganese, or other nutrients not yet evaluated via the DRI [cocess... 

A Tolerable Upper Intake Level (UL) is the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects to almost all individutils in the general population. Unless otherwise specified, the UL represents total intake from food, water, and supplements. Due to alack of suitable data, ULs could not be established for vitamin K, thiamin, riboflavin, vitamin B, pantothenic acid, biotin, and carotenoids. In the absence of a UL, extra caution may be warranted in consuming levels above recommended intakes. Members of the general population should be advised not to routinely exceed the UL. The UL is not meant to apply to individuals who are treated with the nutrient under medical supervision or to individuals with predisposing conditions that modify their sensitivity to the nutrient As preformed vitamin A only... 

In bacteria and plants, the individual enzymes of the fatty acid synthase system are separate, and the acyl radicals are found in combination with a protein called the acyl carrier protein (ACP). However, in yeast, mammals, and birds, the synthase system is a multienzyme polypeptide complex that incorporates ACP, which takes over the role of CoA. It contains the vitamin pantothenic acid in the form of 4 -phosphopan-tetheine (Figure 45-18). The use of one multienzyme functional unit has the advantages of achieving the effect of compartmentalization of the process within the cell without the erection of permeability barriers, and synthesis of all enzymes in the complex is coordinated since it is encoded by a single gene. 

In an investigation of the water-soluble vitamins in human skin,71 it was found that 15 individuals showed relatively small ranges (less than 2-fold) for vitamin B12, folic acid, and biotin about 2-fold ranges in the cases of riboflavin, niacin, and thiamine about a 4-fold range in the case of ascorbic acid, and more than a 5-fold range in the case of pantothenic acid. In another study72 it was found that the total choline content of normal skin varied in four individuals over approximately a 10-fold range 127 to 1200 ig. per gm. The variation in the free choline in the same individuals was relatively small. 

Pantothenic acid is widely distributed in all foodstuffs. The name is derived from the Greek for from everywhere, as opposed to other vitamins that were originally isolated from individual rich sources. 

Pantothenic acid has also been called vitamin Bf. Excellent sources of the vitamin ore liver. egg.s. and cereals. It is found, however, in the form of CoA. This coenzyme cannot be absorbed directly from the gut. Although no experiments have been conducted in humans, studies on animals indicate that the coenzyme must be hydrolyzed to panthenene and pantothenate. " which arc absorbed by passive diffusion. Human intestinal cells contain enzymes tltat can hydrolyze the coenzyme. Pantothenate is the major form circulating in the blood and is absorbed by individual cells. Once inside ihe cell. CoA is synthesized. 

Besides these studies with individual vitamins, there are studies with rats that had received none of the vitamins of the B group (Morgan and Yudkin, 1957). With 20% sorbitol in the diet, the animals grew well for the 13 weeks of the experiment. The diets were such that they would not produce deficiences of vitamin B12, biotin, or niacin however, we can conclude that sorbitol can spare simultaneously at least thiamine, riboflavin, pantothenic acid, pyridoxine and folic acid. 

Potato extract, orange juice and yeast extract all stimulate the fermentation of glucose and acid production by propionic acid bacteria (Tatum et al., 1936). Stimulation by potato extract is associated with some essential growth factors. If synthetic medium is supplemented with yeast extract, then the addition of individual vitamins (biotin, pantothenate, thiamine or /7-aminobenzoic acid) is unnecessary (El-Hagarawy, 1957). In connection with the ability of P. shermanii to synthesize vitamins Karlin (1966) suggested to include these bacteria into dairy products. For example, kefir enriched with P. shermanii contained increased amounts of vitamin Bi, B2, Bg, PP, Bi2, pantothenate, folic and folinic acid as compared with control samples. Especially high increases in the latter four vitamins were observed. 

Table I summarizes the effects of the various deficiencies of the vitamin B complex upon the response to a variety of antigenic stimuli in different test animals. It is the reviewers opinion that, with the exception of the criticisms already made, this table represents the results of well-controlled, adequate experiments. It is quite apparent that the individual members of the vitamin B complex play a very important role in determining antibody response. Their absence may produce a marked impairment in antibody production. Generalizations on this subject are dangerous, but it would appear that pyridoxine, pantothenic acid, and folic acid deficiencies show the most consistent deleterious effects upon antibody production. It is also apparent that the effects of the individual deficiencies may vary widely depending upon the antigen employed.

Pantothenic acid is widely distributed in all foodstuffs the name derives from the Greek for from everywhere , as opposed to other vitamins, which were originally isolated from individual especially rich sources. As a result, deficiency has not been unequivocally reported in human beings except in specific depletion studies, which have generally used the antagonist co-methyl-pantothenic acid. 

Water soluble vitamins are generally not stored in the body, or are stored only for a limited time and the excess is excreted in the urine. Lipophilic vitamins are stored mainly in the Hver. The reserve capacity, defined as the time during which the need for the vitamin is covered by the organism reserves, is the longest for corrinoids (3-5 years) and vitamin A (1-2 years). The reserve capacity for folacin is 3-4 months, for vitamins C, D, E and K, riboflavin, pyridoxine and niacin it is 2-6 weeks, and for thiamine, pantothenic acid and biotin it is only 4-10 days. Reserve capacity is affected by the history of vitamin intake, the metabolic need for the vitamin and the health status of the individual. 

Pantothenic acid is found in virtually all foods of plant and animal origin, usually in relatively small amountss (Table 5.8). Only a small proportion of the total vitamin content is free acid bound forms such as coenzyme A, acyl-coenzymes A and ACP are mostly present. The pantothenic acid levels in individual foods is highly variable. 

Vitamins, minerals, and electrolytes— Studies have shown that during moderate to severe stresses, more zinc, copper, magnesium, and calcium are lost in the urine. Furthermore, stress results in altered blood levels of vitamins A and C, and of zinc and iron. Also, part of the response to stress includes water and sodium retention, via veisopressin and aldosterone secretion. As for the water-soluble vitamins—thiamin, riboflavin, niacin, pyridoxine (B-6), pantothenic acid, folic acid, and vitamin C stress increases their requirement. However, no dietary recommendations are made for these nutrients for individuals under stressful situations. Still, it seems wise to supply some supplementation before deficiency symptoms appear. 

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