Nutrient requirements 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... 

For some nutrients, such as the vitamins biotin (section 11.12) and pantothenic acid (section 11.13), and a number of trace minerals, deficiency is unknown except under experimental conditions. For these nutrients there are no estimates of average requirements, and therefore no reference intakes. As deficiency does not occur, it is obvious that average levels of intake are more than adequate to meet requirements. For these nutrients there is a range of intakes that is defined as safe and adequate, based on the observed range of intakes. 

These are nutrients that are present in the body, and required by the body in minute quantities, ranging from millionths of a gram (microgram) to thousandths of a gram (milligram). Examples are vitamin B-12, pantothenic acid, chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, selenium, silicon, and zinc. Their minuteness in no way diminishes their importance to human nutrition-many are known to be absolutely essential. 

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. 

Table XII records a group of bacteria for which pantothenic acid itself has been found to be an essential nutrient. In reading Table XII, it must always be borne in mind that the findings refer only to the actual cultures examined. It is not permissible to generalize and to conclude that all strains under a given specific name will have the same nutritional requirements. The nutritional requirements are always relative to the synthesizing ability of the cells of the inoculum, and this may differ from strain to strain within a species, or even from culture to culture of the same strain, depending on the cultural conditions, including the presence of other growth factors.

Bacteria for Which Pantothenic Acid it Required a Nutrient... 

Two cases have been recorded where an organism requires as nutrient only the pantoic acid (as lactone) portion of pantothenic acid, presumably being able to synthesize /3-alanine effectively. These organisms are Aceto-bacter suboxydans (A.T.C.C. No. 621) (392) and a strain of Strept. hemolyt-... 

At higher ethanol concentrations the intracellular alcohol interferes with membrane organization, increasing its fluidity and permeability to ions and small metabolites and inhibiting transport of nutrients. Especially Ca and Mg ions are able to increase the plasma membrane stability. It has been demonstrated that incorporation of unsaturated fatty acids and/or sterol(s) as well as proteolipids into cellular membrane of yeasts helps to alleviate ethanol tolerance. For the synthesis of the unsaturated fatty acids the presence of traces of oxygen under fermentation conditions is required. Further to Ca and Mg ions, other trace elements such as Co, Cu, Mn and Zn " and vitamins, e.g. pantothenate, thiamine, riboflavin, nicotinic acid, pyridoxine, biotin, folic acid and inositol, are essential for the growth and ethanol production by yeasts. 

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