LD2668 .T4 1940 M65 / Master of Science

Vitamin D deficiency has been linked with many health problems. Early research demonstrated the importance of vitamin D for bone health, but it may also play a larger role than first reported in muscle health and function. Specifically, low vitamin D may hinder athletic performance, as such evaluation of serum vitamin D levels in high volume training athletes has merit. The purpose of this study was to evaluate serum levels of 25(OH)D in college athletes to determine how many had levels below the recommended values. Data from student-athletes who were attending a large university in the south included: serum vitamin D levels, demographics information, and injury reports. Mean serum vitamin D level for the group was 34.17 ng/mL ± 0.88. Average injury for the group was 1.3± 0.14. The mean value of serum vitamin D for Caucasian players was 38.3 ng/mL ± 1.33 with a range of 23-59 ng/mL. The mean value of serum vitamin D for African American players was 31.16 ng/mL ± 1.08 with a range of 16-52 ng/mL. African American players had significantly lower serum vitamin D levels (p<0.01) than Caucasian players. Players with one or more injury had significantly lower serum vitamin D values (p<0.05) than players who had zero injuries. Forty-eight players (44.4%) had insufficient levels of vitamin D (20-31.9ng/ml). 60 players (55.6%) had values within normal limits (>32 ng/ml). Players with one or more musculoskeletal injury or fracture had significantly lower serum vitamin D levels (p<0.05) compared to players that had zero injuries. African American players had significantly lower serum vitamin D levels (p<0.01) compared to Caucasian players. It is important for athletes to monitor serum vitamin D levels and adhere to a supplementation protocol when levels are insufficient. / text

Thirteen healthy adult males, ages 20-40, consuming self selected diets, were given instructions to take one 500 mg tablet of ascorbic acid three times a day with their meals for a period of ten weeks. The effect of this daily supplementation on copper status was investigated. An estimation made from a three day diet record kept by each subject indicated their dietary copper intake to be 1.92 mg per day. Determination of serum ceruloplasmin and serum copper done on the first day of the ascorbic acid supplementation period showed that the subjects fell within accepted ranges of normal. All further determinations of these parameters during the experimental period were compared to initial values so that each subject served as his own control. At week seven the high ascorbic acid intake significantly decreased ceruloplasmin by 26 percent. At the end of the ten week ascorbic acid supplementation period, serum ceruloplasmin activity was significantly lowered by 20 percent. The slight increase over week seven was attributed to a drop in compliance to taking the ascorbic acid tablets. Serum copper levels were not significantly affected during the 10 week experimental period although a consistent decrease was observed. Two weeks after acerbic acid was terminated serum ceruloplasmin activity increased but was not significantly different from week ten values. However, when compared to week seven values, a significant increase of 14 percent was observed. Serum copper levels measured two weeks after ascorbic acid supplementation was terminated significantly increased 14 percent over week ten values. The results of this human volunteer study indicate that taking a megadose of ascorbic acid for ten weeks will significantly decrease serum ceruloplasmin activity much like that observed in laboratory animal studies. Based on this finding, one may question the safety of prolonged self-dosage of high amounts of ascorbic acid by adults as encouraged by the popular press. / Graduation date: 1982

Recent studies in men have shown plasma levels of vitamin B-6 and pyridoxal 5'-phosphate (PLP), the active form of vitamin B-6, to increase with exercise. It was hypothesized that muscle glycogen phosphorylase might be the source of these increases as this enzyme has been shown to increase with increasing vitamin B-6 (B6) intake in the rat, seemingly to store PLP. The investigation was designed to study the effects of diet-altered glycogen stores and B6 supplements on B6 metabolism during controlled strenuous exercise. The effect of exercise (EX) on the excretion of 4-pyridoxic acid (4PA), the major B6 urinary metabolite, was also studied. The study consisted of three experimental weeks during which carbohydrate (CHO)-modified diets were fed and six EX tests were administered (one each Wednesday and Saturday). Four trained male cyclists (20-23 years) served as subjects. Week 1 a normal CHO diet was fed (NC diet, 40% of total kilocalories as CHO). During week 2, which began 7 days after week 1, a low CHO diet was fed Sunday through Tuesday (LC diet, 11% CHO) to deplete muscle glycogen. In the same week, the LC diet was followed by a high CHO diet (HC diet, 71% CHO). The HC diet was fed Wednesday through Saturday to replete, or load, glycogen stores. The NC, LC, and HC diets contained 1.64, 1.55, and 1.82 mg of B6, respectively. Week 3, beginning 14 days after week 2, was identical to week 2, but with the daily addition of an 8 mg supplement of pyridoxine. Daily exercise was encouraged Sunday through Tuesday to facilitate glycogen depletion. The EX test consisted of 50 min of continuous bicycle ergometer exercise (30 min at 60% HRmax (maximal heart rate), 15 min at 80% HRmax, and 5 min at 90% HRmax). Blood samples were drawn prior to the exercise test (pre), 2 min prior to the 90% HR max interval (during), immediately post EX (post), 30 min post, and 60 min post EX. Plasma samples were analyzed for PLP, PB6, creatine kinase (a muscle enzyme), and hematocrit and hemoglobin. Urine was collected in 24 hour aliquots and analyzed for 4PA and creatinine. The HC diet was associated with significantly lower pre exercise PB6 and PLP levels than LC diet. This was attributed to the high CHO content of HC. Increased plasma PLP and PB6 levels (pre versus post) were seen for all EX tests. This was significant for PB6 levels of all EX tests. Exercise following LC resulted in smaller pre to post increases in PB6 and PLP than other unsupplemented EX tests, but this was significant only for EX following LC versus NC(Wed). Supplementation resulted in greater pre to post increases in PLP and PB6 than EX following unsupplemented diets, but this was significant only for LC versus LC+B6. Plasma PLP and PB6 levels dropped throughout the 60 min post EX period. The 60 min post PLP levels were significantly below pre for the EX tests following diets NC(Wed), LC, HC+B6. Neither plasma volume percent (%) changes (calculated from hematocrit) nor creatine kinase % changes correlated significantly with % changes in PB6 and PLP. Urinary 4PA was elevated on all EX test days as compared to non-test days, except for EX following LC. Tissue redistribution of B6 appears to be occurring with exercise. With the LC diet, more B6 is needed for increased amino acid catabolism in the liver. In this situation tissue redistribution was not associated with increased conversion of B6 to 4PA. Greater increases in PLP with EX following supplementation suggests increased storage may have occurred. These findings are supportive of the hypothesis that increased PLP levels with exercise may originate from PLP bound to phosphorylase. The need for supplemental B6 for the athlete was not established, as status was adequate with normal intakes. / Graduation date: 1983

Oral contraceptive (OC) users frequently have lower vitamin B₆ status than non-oral contraceptive (NOC) users. However, normal dietary intake, a possible factor, has not been adequately studied. Therefore, 26 OC users and 25 NOC users, of college age, were compared with respect to dietary intake of vitamin B₆ and blood vitamin B₆ levels. OC users had been taking "the pill" for at least five months and NOC users had not taken any estrogen-progestin hormones for at least five months. A 72-hour continuous dietary intake record, kept by each subject, was used to calculate intakes of vitamin B₆ and nine other nutrients. Subjects consumed self-selected diets and none had used vitamin B₆ supplements within two weeks of this study. Intakes of all nutrients studied were comparable between the two groups. The mean intakes exceeded the recommended dietary allowance (RDA) for all nutrients except iron, calories and vitamin B₆. The mean intake of vitamin B₆ (1.4 [plus or minus] 0.5 mg/day for OC and 1.6 [plus or minus] 0.5 mg/day for NOC) did not differ significantly between the two groups. The RDA for this age group is 2.0 mg/day of vitamin B₆. The mean protein intakes were not significantly different for OC versus NOC users (72.6 [plus or minus] 19.4 g/day for OC and 66.9 [plus or minus] 13.6 g/day for NOC). The ratio of vitamin B₆ to protein was calculated for each subject. Mean ratios were 0.020 [plus or minus] 0.004 for OC and 0.025 [plus or minus] 0.01 for NOC users. This difference was significant at p<0.05. The mean ratio for both groups exceeded 0.019, which is considered to be adequate. Fasting blood samples were collected during the luteal phase (NOC) or after seven days of the pill cycle for 0C users. These samples were analyzed for whole blood and plasma (by Lind, 1980) vitamin B₆, using a microbiological assay (S.uvarum). These values were used to calculate vitamin B₆ levels in the red blood cell (RBC). A significant difference (p [less than or equal to] 0.05) was found between the mean level of RBC vitamin B₆ in the 0C users versus the NOC (12.4 [plus or minus] 5.4 ng/ml for 0C and 16.8 [plus or minus] 8.5 ng/ml for NOC). Plasma vitamin B₆ concentrations were also significantly different between the two groups. The mean ratio of plasma vitamin B₆ to RBC vitamin B₆ was not statistically different between 0C and NOC users. A questionnaire was used to compare the subject groups with respect to exercise, alcohol intake, general health, general vitamin B₆ intake and other indices. With the exception of alcohol intake, the mean scores for both groups, from this questionnaire, were similar. 0C users had a significantly higher intake of alcohol than NOC users, as measured by the questionnaire. However, the actual alcohol intake from the dietary record did not differ statistically between the two groups. The lack of a significant difference in vitamin B₆ intake, coupled with significantly different blood vitamin B₆ levels for 0C versus NOC users, tends to indicate that the 0C may be altering vitamin B₆ metabolism. Estrogens may cause a redistribution of vitamin B₆ in various body pools, with the vitamin leaving the blood and entering other tissues. Blood levels are generally used to determine vitamin status. By this assessment, 0C users have a lower vitamin B₆ status than controls. It is recommended that 0C users be encouraged to consume at least 2.0 mg/day of vitamin B₆ in their normal diets. / Graduation date: 1981

The purpose of this study was, first, to investigate whether there is a vitamin B-6 requirement for carnitine synthesis and, second, to investigate the effect of fasting on vitamin B-6 metabolism. An experimental group of 72 rats (6 per group) were fed either a vitamin B-6 deficient diet (-B6) (ad libitum, meal-fed) or a control diet (+B6) (ad libitum, pair-fed). These diets were fed for 6 weeks and then the rats were repleted with the control diet for 2 weeks. The animals were fasted for 3 days before and after repletion. Total acid soluble carnitine (TCN) and free carnitine (FCN) levels were compared in the plasma, liver, skeletal muscle, heart muscle and in the urine of rats fed +B6 diet and -B6 diets. The concentrations of pyridoxal 5'-phosphate (PLP) in the plasma, liver, skeletal muscle, and heart muscle and urinary 4-pyridoxic acid (4-PA) excretion were compared in rats fed the +B6 or -B6 diet. Similar comparisons were made in fasted and non-fasted rats. Also, plasma glucose, liver glycogen, and free fatty acid concentrations were compared. In rats fed the -B6 vs +B6 diet, the TCN concentration was significantly (P < 0.05) lower in the plasma, skeletal muscle, heart muscle and urine. With fasting, the liver TCN concentration of -B6 rats was also significantly lower than that of +B6 rats. After the -B6 rats were repleted with the +B6 diet, the TCN concentrations in the plasma, liver, skeletal muscle, heart muscle, and urine returned to those of the control rats. Thus, the decrease in TCN and FCN concentrations, and the increase of these concentrations after repletion provides evidence for a vitamin B-6 requirement in the biosynthesis of carnitine. Fasting resulted in increased concentrations of PLP in the plasma, liver, and heart muscle of rats fed a -B6 diet. The urinary 4-PA excretion of -B6 rats also increased with fasting. These changes are consistent with a redistribution of vitamin B-6 (as PLP) when there is a caloric deficit. Thus, with fasting, PLP is supplied by an endogenous source, possibly skeletal muscle glycogen phosphorylase. In -B6 vs +B6 rats, liver glycogen concentration was higher and plasma FFA concentration was lower. / Graduation date: 1987

The effect of vitamin B-6 (VB6) deficiency in mice on host susceptibility to primary and secondary Moloney-sarcoma virus (MSV)-induced tumor growth, cytotoxic activities of T cells, antibodies and natural killer (NK) cells, and phagocytosis by macrophages was examined. Five- to six-week old female C57B1/6 mice were fed 20% casein diets with pyridoxine (PN) added at 7 (PN-7), 1 (PN-1), 0.5 (PN-0.5), 0.1 (PN-0.1), or 0 (PN-0) mg per kg diet, which represent 700, 100, 50, 10, and 0% of the VB6 requirement of mice adequate for both growth and reproduction, for 4-5 weeks prior to MSV challenge and throughout the period of tumor development or immunologic testing. Animals fed PN-0.1 and -0 diets developed deficiency signs including significantly lower body weight, denuding of the snout, skin irritation and elevated excretion of xanthurenic acid before as well as after tryptophan loading. VB6 deficiency resulted in significant enhancement of tumor susceptibility. Following MSV/MSB challenge, total incidence of MSV/MSB/splenic tumors was 2/11, 1/11, 4/10, and 8/11 in mice fed PN-1, -0.5, -0.1, and -0 diets, respectively. In response to challenge with P815 mastocytoma cells, primary splenic and peritoneal T cell-mediated cytotoxicity (CMC) was significantly reduced in animals fed PN-0 or -0.1 diet. Mice fed PN-0 diet also showed significantly suppressed secondary T CMC of splenic and peritoneal lymphocytes against P815 tumor cells. Complement-dependent antibody-mediated cytotoxicity against P815 tumor cells, phagocytosis of sheep red blood cells by macrophages, and native and interferon-induced NK cell cytotoxicity against YAC tumor cells were not affected by lack of VB6. The percentage of macrophages present in the peritoneal exudate cells was increased in animals fed PN-0 diet. Immune responses were not enhanced or altered by the excess intake of VB6 (PN-7). The present studies which showed compromised host resistance to MSV oncogenesis and altered T cell cytotoxicity in VB6 deficiency provided practical information on the impaired host defense mechanism by inadequacy resulting from VB6. / Graduation date: 1984

The relative enrichment of skin sebaceous gland lipids with deuterium-labeled α-tocopherol was compared with plasma enrichment to evaluate the delivery of vitamin E to skin. For the first week of this study, each subject consumed a daily dose of deuterated vitamin E (150 mg of an equimolar mixture of RRR-α-[5-(C²H₃)]-(d₃) and all rac-α-[5,7-(C²H₃)₂]-(d₆) tocopheryl acetates) with breakfast. Blood was drawn and skin lipids were collected daily for two weeks, then every other day for the following two weeks. Labeled and unlabeled vitamin E analysis was carried out using liquid chromatography and mass spectrometry (LC/MS). Skin cholesterol, plasma cholesterol and triglycerides were measured to evaluate changes in vitamin E levels relative to lipid content. While d₃ and d₆-α-tocopherols were found in plasma 24 h after the first dose, d₃-α-tocopherol was only detected in the skin sebaceous gland secretions after 1 week of supplementation. This data suggests a skin-mediated delivery system for vitamin E into skin lipid secretions. This finding is also supported by the observation that the ratio of α-to γ-tocopherol was greater in the skin than in the plasma. / Graduation date: 2002

A high performance liquid chromatography (HPLC) procedure using a LiChrosorb-NH₂ column and a eluant buffer of 75:25 (v/v) of acetonitrile:0.05 M KH₂P0₄, pH 5.95, was developed for the successful separation and determination of ascorbic and erythorbic acids in selected food samples. Application of the method, which is sensitive, rapid and simple, for the analysis of ascorbic and erythorbic acids in frozen apples, potato products, fruit and vegetable concentrated juices, frozen juices, natural and artificial flavor drink mixes, and Hi-C drinks gave satisfactory results. Dehydroascorbic and dehydroerythorbic acids in these samples could also be determined after reduction with dithiothreitol. It was verified by HPLC that the presence of erythorbic acid affected the determination of ascorbic acid levels by the spectrophotometric method by causing elevated absorbance readings and hence, abnormally high values. Erythorbic acid seriously affects the true determination of ascorbic acid contents in food samples by the spectrophotometric method. The use of HPLC is recommended for the routine analysis of ascorbic acid of those samples containing both ascorbic and erythorbic acids. / Graduation date: 1986

This investigation was designed to add to present understanding of vitamin B-6 (B6) metabolism during exercise. Ten women, 5 aerobically trained and 5 untrained, were fed 4 controlled diets: a moderate carbohydrate (49%) (MCHO) for 2 weeks, a high carbohydrate (63%) (HCHO) for one week, MCH0+B6 for 2 weeks, and HCH0+B6 for 1 week. A one week MCHO diet separated the non-supplemented (2.3 mg B6) and supplemented (10.3 mg B6) diets. The V02 max of each subject was determined prior to the study. An exercise test was completed on day 5 or 6 of weeks 2, 3, 6, and 7. The test consisted of 20 minutes of cycle ergometer exercise at 80% V02 max, preceded by 10 minutes of warm-up and followed by a 5-10 minute active recovery. Blood samples were collected pre exercise (pre), 2-3 minutes post (post), 30 minutes post (p30), and 60 minutes post (p60) exercise. Samples were analyzed for plasma vitamin B-6 (PB6), hematocrit, and hemoglobin. Urine was collected daily in 24-hr aliquots and samples were analyzed for 4-pyridoxic acid (4PA) and creatinine. For all diets, exercise resulted in a significant increase in PB6 from pre to post and a significant decrease from post to p60, the magnitude of the change being greater with supplementation. PB6 fell below pre levels by p60 for all exercise sessions. 4PA increased significantly from the day before exercise to the day of exercise on all diets. There was no significant effect of dietary carbohydrate on levels of PB6 or excretion of 4PA. ANOVA showed no difference between the groups for PB6 or 4PA, though the trained group had lower PBS and greater 4PA excretion throughout the study despite the controlled intake. Tissue redistribution of B6 seems to occur with exercise. The increased magnitude of change in PB6 with exercise after supplementation suggests an increased storage of the vitamin, most likely associated with glycogen phosphorylase in the muscle. Trained women may have lower levels of PB6 and greater 4PA excretion as the result of a regular exercise program. However, supplementation with B6 cannot be recommended since the status of all subjects was adequate with the diet fed. / Graduation date: 1985