Pantothenic acid requirements/recommendations

About 6 to 8 mg/day has been established as the desirable pantothenic acid intake for adult human beings. Adolescent individuals (over 12 years) and pregnant and nursing women have a particularly high requirement for pantothenic acid (the recommended daily allowance is 10 to 15 mg). The normal diet contains 6 to 12 mg pantothenic acid per day, so that severe deficiency symptoms are rarely seen and are difficult to produce experimentally (2,4,8). 

RECOMMENDED DAILY ALLOWANCE. The amount of pantothenic acid required by human beings has not been determined so, a recommended daily allowance for pantothenic acid has not been made by the Food and Nutrition Board of the National Research Council. Nevertheless, they do give "estimated safe and adequate intakes" beised on proportional energy needs (see section on VITAMIN(S), Table V-5, Vitamin Table). Further, they suggest that a higher intake may be needed during pregnancy and lactation. 

Vitamins are chemically unrelated organic compounds that cannot be synthesized by humans and, therefore, must must be supplied by the diet. Nine vitamins (folic acid, cobalamin, ascorbic acid, pyridoxine, thiamine, niacin, riboflavin, biotin, and pantothenic acid) are classified as water-soluble, whereas four vitamins (vitamins A, D, K, and E) are termed fat-soluble (Figure 28.1). Vitamins are required to perform specific cellular functions, for example, many of the water-soluble vitamins are precursors of coenzymes for the enzymes of intermediary metabolism. In contrast to the water-soluble vitamins, only one fat soluble vitamin (vitamin K) has a coenzyme function. These vitamins are released, absorbed, and transported with the fat of the diet. They are not readily excreted in the urine, and significant quantities are stored in Die liver and adipose tissue. In fact, consumption of vitamins A and D in exoess of the recommended dietary allowances can lead to accumulation of toxic quantities of these compounds. 

No analytical method has been developed that will simultaneously measure the bound forms in foodstuffs, so conversion of the bound forms to the free form is required to determine pantothenic acid (Figure 20.1). Several enzyme treatments have been proposed for liberation of the bound form from foodstuffs and a mixture of alkaline phosphatase and pantetheinase extraeted from pigeon liver has been recommended (Gonthier et al. 1998a). However, endogenous enzymes contain pantothenic acid and this must be removed from the enzyme solution before use. In contrast, pantothenic acid can be determined directly in plasma and urine samples without enzyme treatment. Red blood cells contain abundant amounts of CoA and enzyme treatment is required to measure pantothenic acid levels in blood. 

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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