The Editors

Judy Anne Driskell, Ph.D., R.D. is Professor of Nutrition and Health Sciences at the University of Nebraska. She received her B.S. degree in Biology from the University of Southern Mississippi in Hattiesburg. Her M.S. and Ph.D. degrees were obtained from Purdue University. She has served in research and teaching positions at Auburn University, Florida State University, Virginia Polytechnic Institute and State University, and the University of Nebraska. She has also served as the Nutrition...

Nicotinic Acid Doses

Large doses of nicotinic acid, with no reported toxicity, have been used for a wide variety of purposes including as a purported ergogenic aid,89 to treat schizophrenia,10 to treat pellagra,5 to examine the effects on bouts of exercise,11-21 to reduce plasma FFA levels,2223 and most commonly as an agent to improve cholesterol profile.24-36 The amount of the nicotinic acid dose and the time for treatment varies considerably for the purposes mentioned above. As a possible ergogenic aid, FIGURE...

Oxidative Stress And Damage

In response to endurance exercise, oxygen (O2) consumption increases 10- to 20-fold systemically and as much as 100- to 200-fold at the level of the skeletal muscle, resulting in substantially increased mitochondrial electron flux.36 Vigorous exercise results in increased lipid peroxidation,30 DNA damage37 and protein oxidation.38 Leakage of electrons from the mitochondrial electron transport chain is considered a main source of ROS during exercise.2 Other potential ROS sources include enhanced...

Vitamin E Supplementation In Exercise

In a number of studies, vitamin E supplementation has been demonstrated to reduce steady state concentrations of lipid peroxidation markers without affecting exercise-induced increases in oxidative stress.47,49,54,64 Compared with pre-supplementation, resting concentrations of breath pentane and plasma MDA were significantly reduced by 6 weeks' supplementation with 600 mg a-tocopherol, 1000 mg ascorbic acid and 30 mg P-carotene at rest, prior to and during a 30 min run.54 In trained cyclists,...

Research on Current Status

Several research reports are concerned with the biochemical status of folate in athletes. Telford et al. divided 86 Australian athletes into a treatment group (n 42) and a placebo group (n 44). Dietary recalls revealed that both groups were receiving adequate folate in their diet. The treatment group received an additional 200 g of folate daily for 7 to 8 months of hard exercise. The athletes were basketball players, gymnasts, swimmers, or rowers. The supplemented athletes were found to have a...

Future Research Directions or Needs

Research is needed to determine the validity of having supplements containing high amounts of vanadium in the marketplace. This research should definitively establish the toxicity threshold for vanadium and determine whether long-term high consumption of vanadium could lead to pathological disorders such as hypertension.236,237 Studies are needed to determine whether supra nutritional, but non-toxic, intakes of vanadium enhance athletic performance or bone health. Definition of a biochemical...

Summary And Recommendations For Athletes

Based on available research, riboflavin requirements appear to increase with exercise demands. Despite the anticipated effect of riboflavin deficiency on physical exercise, relatively few studies have shown a relationship. Many research studies have indicated that physical activity may deplete riboflavin status. However, there is no evidence that the riboflavin status in well nourished athletes is different from well nourished non-athletic controls. Furthermore, to date, limited data is...

Animal

At least one animal study is of significance to athletes. One of the concerns with hyperhomocysteinemia is the effect on endothelial function. Hyperhomocysteinemia results in decreased availability of nitric oxide and impairs vascular function, two early events in atherosclerosis. The effect of exercise on nitric oxide synthase, the enzyme necessary for nitric oxide production, was investigated using rats that were subjected to treadmill running. The exercise increased the activity of nitric...

Dietary Recommendations

In the human studies described above, the subjects responded to boron supplementation (3 mg day) after consuming a diet supplying only about 0.25 mg of boron 2000 kcal for 63 days. Thus, humans apparently receive benefit from a boron intake above 0.25 mg per day or have a dietary boron requirement above this amount. A World Health Organization Expert Consultation on Trace Elements in Human Nutrition suggested that an acceptable safe range of population mean intakes for boron for adults could be...

Summary And Recommendations

Historical and scientific evidence demonstrate that vitamin C deficiency or even marginal vitamin C status can adversely affect physical performance. Ascorbic acid can adversely affect physical functioning at several different metabolic sites such as impaired collagen formation leading to increased ligament and tendon problems decreased synthesis of carnitine ,which would impair the use of fatty acids as an energy source decreased synthesis of epinephrine and norepinephrine resulting in...

Chemistry

Vitamin B12 in the commercial form is generally cyanocobalamin. The chemical structure of cyano-cobalamin consists of a planar coordination complex of four conjoined pyrrole rings surrounding a central cobalt atom. This structure is similar to the iron porphyrins as in heme. The cyano (CN) group is attached to one of the available Cobalt (Co) sites, while attached to the other site is a ribonucleotide, which is additionally attached to the pyrrole ring structure by an aminopropanol linkage....

Absorption Distribution and Elimination

The absorption of B12 is a highly regulated process and defects in it are the primary cause of deficiency.7 Dietary B12 is cleaved from dietary and salivary proteins by acid in the stomach and by pancreatic proteases. B12 is then bound to intrinsic factor, a glycoprotein secreted by the gastric parietal cells.7 Binding to intrinsic factor protects B12 from enzymatic digestion in the gastrointestinal tract. The cobalamin-intrinsic factor complex traverses the intestinal tract to the ileum, where...

Recommended Dietary Allowance

Riboflavin deficiency can lead to a variety of clinical abnormalities including degenerative changes in the nervous system, anemia, endocrine dysfunction and skin disorders, and can lead to an increase in the susceptibility to carcinogens.12-14 Feeding studies, in which clinical signs and symptoms of riboflavin deficiency were observed, were used to determine the recommended dietary allowance (RDA).15 The 1989 RDA for riboflavin was determined on the basis of energy and protein intake (0.6 mg...

Vitamin A Status And Exercise Physiology

The best available assessment of vitamin A status is obtained from analysis of serum or plasma by high-performance liquid chromatography (HPLC)49 after extraction with organic solvents. The method separates retinol, the major form of vitamin A in plasma, from retinyl esters, which are usually absent in samples from fasting subjects. High amounts of retinyl esters in plasma indicate recent intake of preformed vitamin A (diet or supplement) or excessive habitual consumption, with possible...

Ii

Methylmalonyl-CoA 3-Hydroxypropionate & 2-methylcitrate C C SCoA- HOOC CH2 C CH C SCoA deficiency 3-Hydroxyisovaleric acid & 3-methylcrotonyl glycine FIGURE 9.3 Biotin-dependent steps in intermediary metabolism. ACC, acetyl-CoA carboxylase PC, pyruvate carboxylase PCC propionyl-CoA carboxylase MCC, O-methylcrotonyl-CoA carboxylase. also mediated through malonyl-CoA, which is an inhibitor of fatty acid transport into mitochondria. Acetyl-CoA carboxylase may also play a role in biotin...

Functions Of Vitamin A

Vitamin A constitutes a vital part of our visual system.2 Photoreceptors of the retina in the eye (rods) contain rhodopsin, a photo-sensitive pigment composed of 11-cis-retinal and a protein, opsin. Visual impulse is produced when 11-cis-retinal absorbs a photon, changes to all-trans-retinal, and disengages from opsin. For continuous vision, rhodopsin must be regenerated by isomerization of all-irans-retinol to 11-cis-retinol and the oxidation of the latter to 11-cis-retinal. These reactions...

Table 105

Plasma Concentrations (Mean SD) of Choline (MM) before and after Exercise and Percent Change with and without Choline Supplementation Conlay 59 None 10.1 0.4 M 6.2 1.2 M -39 Conlay 18 None 14.1 1.2 M 8.4 0.6 M -40 Buchman 61 Placebo 9.6 3.6 M 7.0 3.6 M -27 Deuster 62 Placebo 7.9 2.6 M 7.1 1.7 M -10.4 von Allw rden 31 Placebo Triathletes 12.1 1.5 M 10.0 2.1 M -17 von Allw rden 31 Placebo Runners 14.5 2.8 M 14.9 1.7 M +3 Spector 63 Placebo -8.8 M -10.0 M - +12 Warber 73 Placebo 8.1 1.8 M 7.9 1.0...

General Population

International approaches to food fortification with folate vary. The United States mandates folate fortification while the United Kingdom, some European countries, Australia and New Zealand have voluntary fortification policies. The voluntary fortification of food with folate at the level of 50 of the recommended daily dose resulted in a beneficial effect on the folate status of young South Australians, but not at the level required for maximal prevention of neural tube defects.83 In a report...

Future Research

There is a paucity of research expressly aimed at determining the need for additional folate for the athlete to support maximum performance and control the rises in serum homocysteine that occur as a result of exercise. The relationship between exercise and hyperhomocysteinemia needs to be explored further and there is a conspicuous need for additional research to determine whether an increase in the consumption of folate beyond the recommendation for the general population will benefit the...

Introduction

Fat-soluble vitamin A is an essential factor for vision, growth and reproduction of all vertebrate animals, including humans. It is derived from certain carotenoid pigments synthesized by plants, long-chained hydrocarbon compounds, constructed of eight 5-carbon isoprene units (C40). To possess provitamin A activity, the carotenoids must have at least one cyclical structure of the P-ionone ring on either end. P-Carotene, the orange-red pigment of carrots, theoretically may yield two molecules of...

Info

Comparison of Multiple Vitamin-Mineral Formulas Studied for Effects on Exercise Performance and Metabolism McCollum Nelson Keul Haralambie Van Dam Keul van der Beek Barnett Colgan DVa Beneroc 3.5 g sucrose, Phosphorus reported as phosphate Beneroc 3.5 g sucrose, Phosphorus reported as phosphate Beneroc 3.5 g sucrose, Phosphorus reported as phosphate Beneroc 3.5 g sucrose, Phosphorus reported as phosphate Betaine HCL, Inositol, Lecithin, Liver, PABA, Pancreatin, Rice bran extract, Safflower oil,...

Metabolism

Vitamin D is a fat-soluble vitamin that is primarily absorbed through the intestinal tract (small intestine) via the inclusion of chylomicrons from transport through the lymphatic system.4 Calcitriol, an active steroid hormone, is created when stimulation of parathyroid hormone (PTH) occurs. The stimulated PTH will cause a downstream effect of stimulating 1-hydroxylase activity in the kidney so that the vitamin D precursor 25 hydroxyvitamin D3 (25-OH D3) is produced. The 25-OH D3 is converted...

Effects Of Physical Performance

Due to riboflavin's involvement in many metabolic functions critical to exercise performance, its use as a performance enhancer has emerged. Specifically, riboflavin is involved in muscle cell energy metabolism. Recall that FAD and FMN are important in the metabolism of glucose, fatty acids, glycerol and amino acids for energy. When physical activity is performed, stress is put upon the biochemical pathways involved in the metabolism of these substrates.1228 Before we can examine riboflavin's...

Exercise And Ascorbic Acid Requirements

Various tissues such as the adrenal glands, spleen, liver and brain. This would seem to indicate that exercise increased the need for vitamin C in these animals. Studies evaluating the effect of exercise on ascorbic acid needs in humans are greater in number and more diverse in their approach as compared with animal studies. Human studies have addressed the relationship between exercise and vitamin C for blood plasma and leukocyte concentrations of the vitamin, excretion in the urine, immune...

Effect Of Deficiency Or Excess On Physical Performance

Lack of evidence of a significant increase in urinary iodine excretion during exercise suggests that the changes in thyroid hormone metabolism are perhaps transitory and compensated for by feedback mechanisms in the body. Current opinion is that there is no evidence to suggest a greater requirement in physically active individuals, and that iodine intake in athletes is adequate or excessive.74,75 This is probably due to, and may be also a reason for, the complete lack of research on the role of...

Evaluation Of Vitamin A Intake Among Athletes

A great majority of the available studies reported total vitamin A intake without specifying the proportion obtained from animal and plant sources, and many used International Units, which only added to the confusion when reporting total vitamin A intake from mixed foods and supplements. Recently introduced new conversion factors for vitamin A activity of carotenoids4 render all previous reports inaccurate, because of the overestimated contribution from plant sources. Adult athletes are usually...

Toxicity

The hexavalent form of Cr (Cr6+), used for industrial purposes such as dyes, leather tanning and chrome plating, is toxic, and exposure to this form has caused short-term effects such as asthma or bronchitis, or long-term carcinogenic effects.53 Cr6+ passes through the cell membrane where it reacts with DNA in the process of being converted to its trivalent form, with the potential for genotoxic effects.54 One tissue culture study reported that high concentrations of Cr(pic)3 caused chromosome...

General Properties and Metabolic Functions

The signs of molybdenum deficiency in animals have been reviewed.93 In rats and chickens, molybdenum deficiency aggravated by excessive dietary tungsten results in the depression of molybdenum enzymes, disturbances in uric acid metabolism and increased susceptibility to sulfite toxicity. In goats, deficiency uncomplicated by high dietary tungsten or copper resulted in depressed food consumption and growth, and impaired reproduction characterized by infertility and elevated mortality in both...

Copper Requirments Of Athletes

The FNB defines the dietary reference intakes (DRI) as reference values that are quantitative estimates of nutrient intakes to be used for planning and assessing diets for apparently healthy people. They include not only RDAs but also three other types of reference values.4 These reference values include the adequate intake (AI), the recommended average daily intake based on experimental determinations or estimates of nutrient intakes by groups of healthy people the tolerable upper intake level...

Copper and Mitochondrial Oxidative Stress

Four oligomeric enzymes, NADH ubiquinone oxidoreductase (complex I), succinate ubiquinone oxidoreductase (complex II), ubiquinol cytochrome c oxidoreductase (complex III) and ferrocyto-chrome c oxygen oxidoreductase (complex IV), compose the mitochondrial electron transport chain located in the inner mitochondrial membrane. Electrochemical energy derived from the transfer of electrons between these enzymes to molecular oxygen drives the vectorial translocation of protons across the inner...

Copper Concentrations In Blood And Body Organs

The human body contains about 1.6 mg of Cu kg of body weight with variable distributions in various organs and blood. Examples of Cu concentrations in various tissues include kidney, 12 mg kg liver, 6 mg kg brain, 5 mg kg heart, 5 mg kg bone, 4 mg kg and muscle 0.9 mg kg. Bone contains 40 of body Cu, the highest percentage of any other organ muscle is second at about 23 . These organs also make up the greatest percentages of the body mass. Blood contains about 6 of total body Cu. The Cu...

Thiamin In Physical Activity And Exercise

Thiamin is important for physically active individuals, given its critical role in carbohydrate and amino acid metabolism. Manore67 reported that thiamin, riboflavin, vitamin B-6, niacin, pantothenic acid and biotin are involved in energy production during exercise. Consequently, it has been suggested that thiamin deficiency may lead to decreased athletic performance.68 To investigate whether physical activity and exercise increase the dietary requirements of thiamin, researchers have compared...

Effect of Exercise on Thyroid Function

Exercise appears to enhance the rate of utilization or disposal of T4.25 Evidence for an increase in T4 metabolism induced by physical activity comes from research, using the radioactive T4 turnover technique in which the loss of a single injection of T4 125I from the plasma was determined as a function of time, in horses26 and rats,27 28 as well as in athletes.29 In athletes, exercise resulted in the degradation of circulating T4 by 17 per day compared with 10 in the control group.29 This...

Watersoluble Vitamins And Choline

Numerous researchers have investigated the ergogenic effects of ascorbic acid (vitamin C) and the results of these studies are mixed. Vitamin C deficiency or even marginal vitamin C status is known to adversely influence physical performance. Reports exist that up to 25 of athletes consumed less than the RDA for vitamin C. Several studies indicate that strenuous or prolonged exercise increases the need for vitamin C. For subjects having adequate vitamin C status prior to supplementation,...

Identity And Roles Of Vitamins And Trace Minerals

Vitamins are an extremely diverse range of low-molecular-weight compounds that have been classified more by legislative definitions than by common biochemical functions. Vitamins recognized by the Food and Nutrition Board of the Institute of Medicine of the National Academy of Science in the United States include Vitamin A (retinols and beta carotene) Vitamin Bj (thiamin) Vitamin B2 (riboflavin) Vitamin B3 (niacin and niacinamide) Vitamin B6 (pyridoxine and related congeners), Vitamin Bj2...

Metabolic Functions Of Selenium

Since the discovery of cytosolic GSHPx, other selenoproteins including additional antioxidant enzymes have been identified in mammals. A distinct, glycosylated GSHPx has been found in the plasma and a membrane-associated enzyme, phospholipid hydroperoxide GSHPx (PLGSHPx) has been reported to be widely distributed in tissues.1011 While an exact function is not totally clear, selenoprotein-P is found in plasma and tissues and appears to have some antioxidant or selenium transport properties.1012...

Effects Of Selenium On Athletic Performance

Most research in the area of Se and exercise has focused on the role of Se in the antioxidant enzyme GSHPx which, using GSH, converts H2O2 to water. Whole-body and especially muscle oxygen uptake increases sharply during intense physical exercise leading to increased oxidative stress.61 This oxidative stress may be related to production of ROS such as superoxide in the mitochondria during exercise. Superoxide, when acted on by superoxide dismutase (SOD), produces H2O2, which can then be...

Role of Copper in Blood Cell Formation and Function

Although knowledge of the exact role of Cu in blood cell formation is limited, observations in Cu-deficient animals and humans show prominent connections between Cu status and blood cell production, survivability and function. These functions could be compromised during strenuous exercise. In both animals and humans, Cu deficiency presents with a reduced population of RBCs that are smaller than normal and with a reduced hemoglobin concentration. Although the signs mimic Fe deficiency,...

Vitamin b6 in sports and exercise

Vitamin B6 is a cofactor for many metabolic reactions that produce energy, including the transamination of amino acids and the release of glucose from glycogen. Thus, it is not surprising that researchers would ask whether exercise and physical activity increases the need for vitamin B6. This section will review the current literature examining whether physical activity increases the need for vitamin B6 due to training-induced changes in metabolism that require the vitamin. First, the...

Interaction Of Selenium With Other Nutrients

Vitamin E and Se function as synergistic antioxidants, and many of the signs and symptoms of a double deficiency of these two nutrients can be prevented or will be improved by supplementation with either nutrient.22 Beck et al.32 reported that vitamin E deficiency increased the cardiac pathology associated with Coxsackie B3 infection in mice, especially in mice fed diets high in menhaden oil as opposed to lard, for dietary fat. Work by Beck et al.30,32 on the effects of both Se and vitamin E...

Vldl

FIGURE 10.2 Metabolic Pathways of Choline. Adapted from Blusztajn.27 in the liver. The betaine pathway also provides methionine for protein synthesis.32 Third, choline is a precursor for compounds that serve critical cell signaling functions, including phosphorylcholine 33 platelet-activating factor, (PAF), a choline plasmalogens and sphingophosphorylcholine.34 In addition, the choline-containing phospholipids, phosphatidylcholine and sphingomyelin, are precursors for two other molecules that...

References

Bender, D.A., Nutritional Biochemistry of the Vitamins, 2nd ed., Cambridge University Press, Cambridge, U.K., 2003. 2. Combs, G.F., The Vitamins. Fundamental Aspects in Nutrition and Health, 2nd ed., Academic Press, San Diego, 1998. 3. Institute of Medicine, Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B& Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline, National Academy Press, Washington, D.C., 1998. 4. Rucker, R.B., Suttie, J.W., McCormick, D.B., and...

Functions Of Iodine

Iodine functions as an integral part of the thyroid hormones, the pro-hormone thyroxine (T4), and the more potent active form 3,5,3'-triiodothyronine (T3) which is the key regulator of important cell processes.3 Selenium is essential for normal thyroid hormone metabolism as a component of the iodothyronine 5'-deiodinases that control the synthesis and degradation of the biologically active hormone, T3.4 The thyroid hormones are required for normal growth and development of individual tissues...

Effects Of Increased Intake Of Vitamins And Trace Minerals On Exercise Performance And Metabolism

Other chapters in this book are concerned with individual vitamins and minerals therefore, a brief review of the effects of multiple vitamin-mineral supplementation on exercise parameters will be presented in this chapter. At present, there is considerable controversy over the use of and need for essential micronutrient supplementation in exercising humans. After examination of the existing human studies on multiple vitamin-mineral supplementation and physical performance, the reader should...

Basis for Sports Nutrition Interest

There is relatively little reason for molybdenum to be of interest to physically active people. Molybdenum is a transition element that readily changes its oxidation state and can thus act as an electron transfer agent in oxidation-reduction reactions in which it cycles from Mo6+ to reduced states. This is the basis for molybdoenzymes' catalyzing the hydroxylation of various substrates using oxygen from water. Molybdenum hydroxylases may be important in metabolizing drugs and foreign compounds...

Assessment of thiamin

The total thiamin concentration in the body is about 25-30 mg, where TPP is the primary form. In addition, about 80 of the thiamin in whole blood is present in erythrocytes.60 Because the body cannot store thiamin for long periods, thiamin deficiency may develop without adequate regular ingestion of thiamin. Therefore, thiamin assessment provides a useful tool not only in identifying thiamin deficiency, but also to evaluate the nutritional status of different groups. Many procedures are used to...

Effect of Exercise on Iodine Metabolism

There has been very little study of the effects of exercise on iodine metabolism. Just two studies22-24 have investigated the iodine in sweat and urine of athletes. In a study of 10 Japanese rowing club students in 1985, the iodine concentration in sweat was close to 37 g l regardless of urinary iodine excretion, which was 50-393 (mean 149) g day during 6 consecutive days of a summer training camp, similar to that of 40-441 (mean 153) g day in five sedentary students,22 In a subsequent Chinese...

Dietary Intake And Status Assessment

Dietary and Supplemental Sources 1. Pantothenic Acid Human requirements for pantothenic acid have not yet been quantified. Hence, recommendations for adequate intake (AI) are based on the average daily intake in healthy individuals.58 The AI is 5 mg day of pantothenic acid for adults of both genders. The AI of pantothenic acid in pregnant and lactating women is 6 mg day and 7 mg day, respectively.17,58 Pantothenic acid is widely distributed in plant, animal and microbial cells. In...

Nicotinic Acid And Substrate Availabilityperformance

Nicotinic Acid Effects on Fuel Utilization at Rest Numerous investigators have demonstrated changes in FFA mobilization as a result of ingesting or infusing nicotinic acid. The articles that were reviewed all indicated that plasma or serum FFA levels were lowered by the presence of nicotinic acid. Havel, Carlson, Ekelund and Holmgren37 investigated the effects of norepinephrine and nicotinic acid on energy metabolism in seven 21-26-year-olds. They ingested 1-3 g of nicotinic acid daily for 3...

Choline And Exercise Interactions

A role for choline in physical activity evolved based on the importance of ACh in neuromuscular function.7111617 It was reasonable to postulate that, as a neurotransmitter released at the neuromuscular junction in response to nerve stimulation, ACh may be rate limiting for exercise performance. In particular, if release of ACh by cholinergic neurons were related to the level of physical activity,16 then as the duration or intensity of the physical activity increased, comparable increases in ACh...

Conclusions And Future Issues

Choline is an essential nutrient that is only beginning to be fully appreciated and understood. There is little doubt that choline serves a multitude of important roles, both functional and structural, that can influence overall health and physical and cognitive performance. Whether supplementation with choline will overcome existing deficits, enhance selected physical activity and performance or provide a safe and effective approach for treating various illness and disorders remains to be...