Changes In Plasma Vitamin Research Articles

Outcome of High Dose Vitamin D on Prognosis of Sepsis Requiring Mechanical Ventilation: A Randomized Controlled Trial

Abstract Background Critically ill patients have an increased requirement for vitamin D in sepsis and these patients have low levels of vitamin D. The researchers validated the efficiency and safety of high-dose oral vitamin D (50,000 IU) in patients with sepsis requiring mechanical ventilation. Methods Seventy five patients were randomly assigned to 2 groups (Group I = 37 patient and Group II = 38 patient) in accordance with the vitamin D treatment regimen: Group I (GI): patients received 50,000 IU vitamin D crushed and diluted in 50 ml of water and delivered to patients in the nasogastric tube (NGT) once daily for 5 consecutive days; Group II (GII): patients received daily requirements of vitamin D (5000 IU/ day) crushed in 50 ml of water and delivered to patients in the nasogastric tube (NGT) once daily for 5 consecutive days. Primary outcome of this study was the change in procalcitonin levels at day 7 and the changes in plasma vitamin D levels were secondary outcomes. Results Procalcitonin (PCT) decreased at day 4 and day 7 in study groups, procalcitonin (PCT) levels at days 4, 7 were significantly lower in high dose group (p < 0.032 and p < 0.013, respectively) and procalcitonin (PCT) levels reductions (day 7 – day 0) were significantly higher in high dose group (p < 0.010). Serum vitamin D (25(OH)D) levels increased at day 4 then decreased at day 7 in study groups, serum Vitamin D (25(OH)D) levels at days 4, 7 were significantly higher in high dose group (p < 0.001 and p < 0.001, respectively) and serum Vitamin D (25(OH)D) levels elevations (day 7 – day 0) were significantly higher in high dose group (p < 0.001). Conclusion The early use of high-dose oral vitamin D in patients with sepsis requiring mechanical ventilation in combination with the standard treatment for sepsis lowered the procalcitonin level, increased the antioxidant status, and improved the illness severity. Trial Registration This trial is registered with ClinicalTrials.gov Identifier (NCT05244018).

92 Seasonal variation in plasma vitamin A and E concentrations in horses with or without pasture access

Vitamins A and E are essential nutrients for horses and often provided in the diet by fresh forage but become depleted when forage is cut and dried for hay and can lead to potentially fatal health problems in horses. This study evaluated seasonal changes in plasma vitamin A and E for a mature horse herd in the Upper Midwest to determine the impact of pasture access on the prevalence of vitamin deficiency. Researchers hypothesized horses on dry lot would be deficient all year while horses with pasture access would have increased vitamin A and E concentrations during the grazing season. The study took place between February and November 2022 in River Falls, Wisconsin. Twenty-seven mature horses were divided into 2 treatments based on management practices including 1) horses consuming a hay-only diet in a dry lot (n = 13) and 2) horses with pasture access in the summer (n = 14). All horses had ad libitum access to water and a vitamin and mineral mix (200 IU/kg Vitamin E; 176,320 IU/kg Vitamin A) for the duration of the study and received ad libitum cool-season grass hay round bales from September through May. Hay-only horses continued this diet from June through August while pastured horses continuously grazed cool-season grass pasture. Jugular venous blood samples were taken in February (winter), May (spring), August (summer), and November (fall) and plasma samples were sent theMichigan State Veterinary Diagnostic Lab for analysis of plasma vitamin A and E concentrations. Data were analyzed using PROC MIXED in SAS with significance set at P ≤ 0.05. Adequate vitamin A was classified as 175 to 300 ng/ml, and adequate vitamin E was classified as 2.0 to 4.0 µg/ml. Vitamin A deficiency was observed in 81% and 85% of horses in winter and spring, respectively, with an average concentration of 145 ng/ml. Pastured horses exhibited an increase in plasma vitamin A in the summer compared with dry lot horses (P ≤ 0.05), however 64% of pastured horses remained deficient. In the fall, vitamin A deficiency increased to 97% for all horses and plasma vitamin A averaged 139 ng/ml. When evaluating vitamin E, 70 to 74% of horses were deficient in the winter and spring, respectively, with an average concentration of 1.83 µg/ml. Plasma vitamin E concentrations did not change over time for dry lot horses and remained inadequate in the summer at 1.43 µg/ml (P > 0.05) while concentrations in pastured horses rose to 2.4 µg/ml (P ≤ 0.05). These results confirm recommendations to provide additional vitamin A and E to horses on a hay-only diet and demonstrates the short-lived increases in vitamin A and E for horses provided limited pasture access.

Maternal plasma vitamin D levels across pregnancy are not associated with neonatal birthweight: findings from an Australian cohort study of low-risk pregnant women

BackgroundIn utero environments can be highly influential in contributing to the development of offspring obesity. Specifically, vitamin D deficiency during pregnancy is associated with adverse maternal and child health outcomes, however its relationship with offspring obesity remains unclear. We assessed maternal vitamin D status across pregnancy, change in plasma vitamin D concentrations and associations with neonatal birthweight, macrosomia and large for gestational age.MethodsWomen (n = 221) aged 18–40 years with singleton (low-risk) pregnancies, attending antenatal clinics at a tertiary-level maternity hospital were recruited at 10–20 weeks gestation. Medical history, maternal weight and blood samples at three antenatal clinic visits were assessed; early (15 ± 3 weeks), mid (27 ± 2 weeks) and late (36 ± 1 weeks) gestation. Maternal 25(OH)D was analysed from stored plasma samples via liquid chromatography-tandem mass spectrometry (LC/MS/MS). Neonatal growth parameters were collected at birth. Unadjusted and adjusted linear and logistic regression assessed associations of maternal vitamin D with birthweight, macrosomia and large for gestational age.ResultsMean plasma 25(OH)D increased from early (83.8 ± 22.6 nmol/L) to mid (96.5 ± 28.9 nmol/L) and late (100.8 ± 30.8 nmol/L) gestation. Overall 98% of women were taking vitamin D-containing supplements throughout their pregnancy. Prevalence of vitamin D deficiency (25(OH)D < 50 nmol/L) was 6.5%, 6.3% and 6.8% at early, mid and late pregnancy respectively. No statistically significant association was found between 25(OH)D or vitamin D deficiency at any timepoint with neonatal birthweight, macrosomia or large for gestational age.ConclusionsPrevalence of vitamin D deficiency was low in this cohort of pregnant women and likely related to the high proportion of women taking vitamin D supplements during pregnancy. Maternal 25(OH)D did not impact offspring birth weight or birth size. Future studies in high-risk pregnant populations are needed to further assess maternal vitamin D status and factors in utero which promote early life obesity.

Clinical and serological association of plasma 25-hydroxyvitamin D (25(OH)D) levels in lupus and the short-term effects of oral vitamin D supplementation

Background and objectivesData on the association of vitamin D levels and clinical phenotype and disease activity in systemic lupus erythematosus (SLE) is controversial. Further, the optimal dose of oral vitamin D supplementation in SLE is not clear. Thus, the present study was designed to determine the association of plasma vitamin D levels with clinical phenotype, disease variables and serology in a large, cohort of SLE from South Asia and to evaluate the short-term effect of two different dosage regimens of oral vitamin D supplementation on disease flares and plasma vitamin D levels.MethodsThis is a two-phase study. Phase I was a cross-sectional analytical study of patients from north (26.85° N) and south India (11.94° N). Plasma 25-hydroxyvitamin-D(25(OH)D) was measured, and its association with demography, serology, disease activity, Galectin-9 and CXCL-10 was analysed. In phase II, patients with SLEDAI-2KG < 10 and on stable immunosuppression were randomised to receive either high dose (weekly 60,000 U*5, followed by 60,000 U monthly) or routine dose (30,000 U monthly) oral vitamin D. Outcomes were assessed at 6 monthsResultsPhase I included 702 patients with a mean age of 29.46 + 10.7 years. The median plasma vitamin D was 22.83 (13.8–31.8) ng/ml. Deficiency (< 20 ng/ml) was seen in 41.5% of patients. Patients from South India had higher vitamin D levels (27.06 ± 20.21 ng/dl) as compared to North India (17.15 ± 16.07 ng/ml) (p < 0.01). Univariate analyses demonstrated weak negative correlation of vitamin D with SLEDAI2K and positive correlation with age. Galactin-9 had modest correlation with SLEDAI2K but not with vitamin D levels. On multiple linear regression, centre of recruitment (β = 4.37) and age (β = 0.18) predicted (p < 0.05) plasma vitamin D levels.In the phase II, 91 randomised to 2 groups completed 6 months. Median change in plasma vitamin D levels was more in high dose (9.5 versus 2.6 ng/ml; p = 0.04). There were 14 SLE flares and six minor adverse events which were equal across both groups.ConclusionVitamin D deficiency is common in SLE. Geographical location of residence is the major determinant rather than the disease activity. The IFN regulated proteins reflect disease activity independent of vitamin D levels. High-dose oral vitamin D supplementation seems safe and more effective in improving vitamin D levels in SLE.Trial registrationThe second phase of this study was a registered randomised controlled trial CTRI/2019/06/019658 [registered on: 14/06/2019].

Evaluation of changes in plasma vitamin C levels in brain-dead organ donors

Introduction: Inflammatory events after brain death (BD) generally influence the quality of donated organs and adversely affect the outcome of transplant surgeries. Vitamin C is a natural organic compound with potent antioxidant properties. Changes in serum levels of vitamin C (ascorbic acid) following BD are still unknown. Objectives: This study aimed to assess the changes in serum vitamin C levels in brain dead donors in the time elapsed between BD diagnosis and at once before procurement procedure of donated organs. Patients and Methods: In this experimental study, serum vitamin C levels were measured in 37 brain-dead donors (BDDs) at two time points, primarily on admission (R1) and just before organ procurement (R2). The difference between mean values of R1-R2 was analyzed according to the parameters of brain dead donor’s, which consisted of gender, cause of BD, and type of blood group. Results: A total of 37 BDDs (62.2% male) with a mean age of 26.48±18.1 years were included. Time interval between the two samplings was 40.09±12.10 hours. Overall, there was a statistically significant difference between serum ascorbic acid (AA) levels at admission (R1) and immediately before organ procurement (R2) (P=0.016). However, in terms of the cause of BD and blood type, no significant difference in serum AA at the two-time points was detected (P=0.85 and P=0.79 respectively). Conclusion: Significant differences were observed between serum vitamin C levels in the duration between BD diagnosis and immediately before procurement surgery. Therefore, determining the most effective dose of vitamin C supplementation and the best time to administer it to the patients is highly recommended for future studies.

KiwiC for Vitality: Results of a Randomized Placebo-Controlled Trial Testing the Effects of Kiwifruit or Vitamin C Tablets on Vitality in Adults with Low Vitamin C Levels.

Consumption of vitamin C-rich fruit and vegetables has been associated with greater feelings of vitality. However, these associations have rarely been tested in randomized controlled trials. The aim of the current study was to test the effects of eating a vitamin C-rich food (kiwifruit) on subjective vitality and whether effects are driven by vitamin C. Young adults (n = 167, 61.1% female, aged 18–35) with plasma vitamin C <40 µmol/L were randomized into three intervention conditions: kiwifruit (2 SunGold™ kiwifruit/day), vitamin C (250 mg tablet/day), placebo (1 tablet/day). The trial consisted of a two-week lead-in, four-week intervention, and two-week washout. Plasma vitamin C and vitality questionnaires (total mood disturbance, fatigue, and well-being) were measured fortnightly. Self-reported sleep quality and physical activity were measured every second day through smartphone surveys. Nutritional confounds were assessed using a three-day food diary during each study phase. Plasma vitamin C reached saturation levels within two weeks for the kiwifruit and vitamin C groups. Participants consuming kiwifruit showed significantly improved mood and well-being during the intervention period; improvements in well-being were sustained during washout. Decreased fatigue and increased well-being were observed following intake of vitamin C alone, but only for participants with consistently low vitamin C levels during lead-in. Diet records showed that participants consuming kiwifruit reduced their fat intake during the intervention period. Intervention effects remained significant when adjusting for age and ethnicity, and were not explained by sleep quality, physical activity, BMI, or other dietary patterns, including fat intake. There were no changes in plasma vitamin C status or vitality in the placebo group. Whole food consumption of kiwifruit improved subjective vitality in adults with low vitamin C status. Similar, but not identical, changes were found for vitamin C tablets suggesting that additional properties of kiwifruit may contribute to improved vitality.

Changes in plasma vitamin D level and anthropometric measurements after a high-intensity interval training in overweight male adolescents

Changes in plasma vitamin D level and anthropometric measurements after a high-intensity interval training in overweight male adolescents

Nutritional practice effectiveness to achieve adequate plasma vitamin A, E and D during the early postnatal life in Tunisian very low birth weight infants

Objective: To look at changes in plasma vitamin A, E and D concentrations during the early postnatal life and to study their link with growth and mortality in Tunisian very low birth weight (VLBW) infants. Patients and methods: A cohort of 607 VLBW infants had been followed from birth until hospital discharge or death. Blood was collected at birth, at time of maximal weight loss and at time of recovering birth weight. Retinol and α-tocopherol were analyzed using HPLC and 25 hydroxy vitamin D using radioimmunoassay. Results: Vitamin A, D and E deficiencies were very common at birth (75.9%, 74.1% and 65.2%, respectively). The prevalence’s have decreased throughout hospital stay, but remained high at time of recovering birth weight (59.4%, 31.2% and 28.8%, respectively). Vitamin A deficiency was associated with longer hospital stay [OR (95% CI), 1.66 (1.03–2.93)] and vitamin E deficiency was associated with increased neonatal mortality [1.44 (1.01–2.23)]. Conclusions: Current nutritional practices are ineffective to achieve adequate vitamins A, E and D status in Tunisian VLBW infants during the early postnatal life and should be revised. Further work is needed to establish recommended doses of vitamins supplements in these preterm infants.

Lowering of oxidative stress improves endothelial function in healthy subjects with habitually low intake of fruit and vegetables: A randomized controlled trial of antioxidant- and polyphenol-rich blackcurrant juice

Inadequate intake of the recommended five-a-day fruit and vegetable portions might contribute to increased cardiovascular disease risk. We assessed the effects of dietary intake of a blackcurrant juice drink, rich in vitamin C and polyphenols, on oxidative stress and vascular function. This was a double-blind, placebo-controlled, parallel group study of 66 healthy adults who habitually consume <2 portions of fruit and vegetables per day. Participants were randomly allocated to consume 250ml of placebo (flavored water) or low or high blackcurrant juice drink four times a day for 6 weeks. Flow-mediated dilation (FMD) and plasma concentrations of F2-isoprostanes and vitamin C were measured. In the high blackcurrant juice drink group FMD increased significantly (5.8±3.1 to 6.9±3.1%, P=0.022) compared with the placebo group (6.0±2.2 to 5.1±2.4%). Plasma vitamin C concentration increased significantly in the low (38.6±17.6 to 49.4±21.0µmol/L, P<0.001) and high (34.6±20.4 to 73.8±23.3µmol/L, P<0.001) blackcurrant juice drink groups compared with the placebo group (38.1±21.0 to 29.0±17.6µmol/L). F2-isoprostane concentrations were significantly lower in the high blackcurrant juice drink group (225±64pg/ml) compared with the low blackcurrant juice drink (257±69pg/ml, P=0.002) and placebo group (254±59pg/ml, P=0.003). At follow-up, changes in plasma vitamin C correlated significantly with changes in FMD (r=0.308, P=0.044). Consumption of blackcurrant juice drink high in vitamin C and polyphenols can decrease oxidative stress and improve vascular health in individuals with habitually low dietary fruit and vegetable intake.

Short‐ and long‐term changes in plasma vitamin and mineral concentrations following laparoscopic Roux‐en‐Y gastric bypass surgery (812.2)

Over 340,000 bariatric surgeries are performed annually worldwide, many of them on young individuals. While successful weight loss can occur, it has been associated with a number of nutritional deficiencies. In this prospective study, blood was taken from 21 female patients (19 White, 2 Black; age = 44.5 ± 2 yrs; body mass index (BMI) = 54.8 ± 1.7 kg/m2) at baseline and 3 wk, 3 mo., 6 mo. and 12 mo. after RYGB surgery to determine the extent to which select nutrient concentrations change over time. Average BMI at 12 mo. was 36.0 ± 1.4 kg/m2. At baseline, 47.7% were characterized by vitamin D (25OHD) &lt;20 ng/ml and 33.3% had 25OHD between 20‐30 ng/ml. By 12 mo., these levels represented 18% and 38.1% of the subjects, respectively. Iron status was lowest at 3 wks post‐surgery as evidenced by low plasma iron and high transferrin receptor levels. Inflammation was evident (hsCRP &gt;10 mg/ml) at baseline. The highest hsCRP level was observed at 3 wks post‐surgery and decreased over time. Consistent with an acute‐phase response, ferritin levels were highest at 3 wks post‐surgery. Plasma zinc levels were highest at 3 wks post‐surgery. None of the women were characterized with zinc deficiency (&lt;0.5 µg/ml). Prevalence of low copper status (&lt;0.8 µg/ml) at baseline was 14.3% and increased to 31.6% by 12 months. These data support the concept that short and long‐term changes in nutritional status are common after RYGB surgery.

Bioavailability of Vitamins E and C: Does Helicobacter pylori Infection Play a Role?

Background: While the association between bioavailability of vitamins E and C and Helicobacter pylori infection has been extensively researched in gastritis and gastric cancer patients, little is known about this relationship in asymptomatic adults. Aim: To investigate the effect of H. pylori infection on bioavailability of vitamins E and C in asymptomatic adults. Methods: Volunteers from the University of Toronto, aged 18–45 years, were screened, for their H. pylori infection status. H. pylori-negative (n = 32) and asymptomatic H. pylori-positive (n = 27) participants received vitamin C (500 mg) and vitamin E (400 IU) supplements daily for 28 days. Plasma vitamins C, E and thiols concentrations were assessed before (baseline) and after supplementation. Results: Postsupplementation plasma levels of vitamin C and E were significantly higher than presupplementation levels in both groups. Yet, changes in plasma vitamins E and C were not significantly different between the two groups [vitamin C (µmol/l): 13.97 ± 16.86 vs. 20.87 ± 27.66, p > 0.05; vitamin E (µmol/l): 15.52 ± 9.4 vs. 14.47 ± 15.77; p > 0.05 for H. pylori-negative and H. pylori-positive groups, respectively]. In addition, no significant difference was found in plasma thiols levels between groups (p > 0.05). Conclusion: These findings suggest that H. pylori does not influence antioxidants bioavailability in its asymptomatic stages of infection until a factor or combination of factors triggers the inflammation cascade which may lead to increased oxidative stress and possibly reduced bioavailability of vitamins E and C.

Manipulation of lipid bioaccessibility influences postprandial vitamin E concentrations in healthy human subjects: implications for inflammation, oxidative stress and vascular responses.

Postprandial lipemia is associated with an acute elevation in oxidative stress, inflammation and impaired vascular function, which is attenuated by the presence of antioxidant vitamins. We previously reported that slow release (low bioaccessibility) of lipid from whole almonds (WA) during digestion, compared with free oil from almond (AO) or sunflower (SO) seeds, reduced postprandial lipemia (over 8h), but no effects on oxidative stress and vascular function were found1. Subjects (n=20, aged 18‐40y) were fed test meals containing 50g fat provided as WA, AO or SO in a randomised cross‐over design, with 1‐wk washout. Additional analysis to investigate the effects of differences in lipid bioaccessibility on changes in plasma vitamin E and interleukin 6 (IL‐6; inflammatory marker) concentrations are presented. Plasma vitamin E concentrations were lower (mean incremental area under curve with 95% CI) following the WA meal (69 (25, 113)) vs. the AO (150 (211, 88)) and CO (137 (190, 84)) meals; P=0.003. IL‐6 concentrations increased significantly from fasting following the test meals (P=0.023), but did not differ between meals. The concomitant increase in plasma vitamin E with postprandial lipemia from the free oils may counterbalance the deleterious effects of exaggerated lipemia on oxidative stress, inflammation and vascular function.1Berry et al. Am J Clin Nutr 2008;88:922‐9

The Role Of Dietary Zinc Restriction On Antioxidant Status And Oxidative Stress

Approximately 10% of the U.S. population consumes less than half the recommended dietary allowance for zinc and are at risk for zinc deficiency. Zinc is a component of over 300 enzymes and has proposed antioxidant function. Consequently, inadequate zinc consumption may lead to enhanced oxidative stress through several mechanisms including altered antioxidant defenses. In the present study, we hypothesized that dietary zinc restriction would result in lower antioxidant status and increased oxidative damage. We fed Sprague Dawley rats (n = 12/group) either a zinc-adequate (50 ppm), zinc-deficient (<0.05 ppm) or pair-fed diet for 4-weeks and then assessed antioxidant status and oxidative stress parameters. Dietary zinc restriction decreased (p<0.05) plasma antioxidant status by 20%, assessed by the ferritin reducing ability of plasma, which was accompanied by a 50% reduction in plasma uric acid (p<0.05), but no significant change in plasma vitamin C concentrations. Zinc restriction did not significantly decrease plasma or hepatic a-tocopherol concentrations, nor were the protein levels of the hepatic a-tocopherol transfer protein altered. However, zinc restriction resulted in lower hepatic g-tocopherol concentrations (p<0.05), which may be explained in part, by increased (p<0.05) hepatic CYP4F2 protein levels. Lastly, zinc restriction resulted in elevated plasma F2-isoprostanes. Collectively, zinc deficiency had differential effects on antioxidant status and may enhance oxidative stress via increased lipid peroxidation and CYP induction.

Effect of changes in plasma vitamin E level of vascular responses and lipid peroxidation in sickle cell anaemia subjects

The effect of vitamin E supplementation (300 mg/day for 6 weeks) on blood pressure, forearm blood flow, forearm vascular resistance, plasma vitamin E level and lipid peroxidation status was investigated in adult sickle cell anaemia subjects. Ten adults whose ages ranged from 19.0 to 25.0 years (mean 22.8+/-0.8 years) were studied. Vitamin E supplementation had little or no effect on arterial blood pressure but significantly increased forearm blood flow (p<0.001) and plasma vitamin E level (p<0.001). However it significantly decreased lipid peroxidation status (p<0.001) and forearm vascular resistance (p<0.001). The change in plasma vitamin E concentration correlated negatively with change in lipid peroxidation status (r=-0.8; p=0.003). However, change in plasma vitamin E concentration correlated positively with change in forearm blood flow (r=0.8; p=0.006). There was an inverse correlation between change in plasma lipid peroxidation and change in forearm blood flow (r=-0.7; p=0.03). The study therefore shows that in sickle cell anaemia subjects, vitamin E supplementation increases forearm blood flow and reduces forearm vascular resistance and lipid peroxidation. The increase in forearm blood flow correlates inversely with the reduction in lipid peroxidation. This suggests that in sickle cell anaemia subjects, vitamin E supplementation could cause an increase in forearm blood flow by decreasing plasma lipid peroxidation level.

Oxidation of ascorbic acid in stored orange juice is associated with reduced plasma vitamin C concentrations and elevated lipid peroxides

Ascorbic acid oxidizes in refrigerated orange juice, but the physiological relevance of this deterioration is unknown. We compared changes in plasma vitamin C and total lipid peroxides (thiobarbituric acid-reactive substances, TBARS) in the 2-hour period following consumption of commercial orange juices on day 1 vs day 8 of storage (4°C). The ascorbic acid content decreased significantly after storage in juice reconstituted from frozen concentrate (117±8 vs 89±8 mg/8 fl oz, P=.001), but did not change in chilled juice (69±5 vs 64±12 mg/8 fl oz.). The mean incremental TBARS value was less on day 1 vs day 8 for juice from frozen concentrate (−0.46±0.72 and 0.70±0.53, P=.046), but did not differ for chilled juice (0.00±0.49 and 0.54±0.89). The incremental values for plasma TBARS and vitamin C in the 2-hour postprandial period were inversely related (r=−0.48, P=.017). These data indicate that the loss of ascorbic acid in refrigerated juice may impact postprandial oxidative stress.

Muscle injury and antioxidant status in sled dogs competing in a long-distance sled dog race

AbstractExercise is associated with an increase in the production of oxidants that may be instrumental in the development of exertional rhabdomyolysis. We speculated that participation in a long-distance sled race would alter antioxidant capacity of dogs, in conjunction with increases in indices of rhabdomyolysis. The objective was to determine the effect of participation in a long-distance sled dog race on antioxidant capacity and plasma creatine kinase (CK) activity in sled dogs. This was a prospective, longitudinal study on a convenience sample of 57 Alaskan sled dogs participating in a 1600 km sled dog race. Blood samples were collected before racing (31 dogs) and after racing (39 dogs) for measurement of plasma vitamin E concentration; CK, aspartate aminotransferase (AST) and caeruloplasmin (CER) activity; and red-blood-cell (RBC) glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity. CER and GPX activities after the race were 26% and 14% lower, respectively, than before racing whereas CK and AST were 300% and 170% greater. There was no change in plasma vitamin E concentration or RBC SOD activity. We conclude that completion of a long-distance sled dog race involving prolonged and repeated submaximal exercise results in a reduction in enzymatic antioxidant activity in the blood of sled dogs.

Changes in Vitamin C Concentrations in Plasma and Milk from Dairy Cows After an Intramammary Infusion of Escherichia coli

Plasma and milk concentrations of ascorbic acid and dehydro-L-ascorbic acid (DHAA) were measured before and after 21 Holstein cows (approximately 26 DIM) were given an intramammary infusion of Escherichia coli. Blood, milk from the unchallenged quarters, and milk from the challenged gland were sampled immediately before challenge (d 0) and 24 h and 7 d postchallenge. Plasma vitamin C (ascorbic acid + DHAA) concentrations decreased 39%, and concentrations of vitamin C and ascorbic acid in milk from the challenged quarter decreased 52 and 62%, respectively, in samples taken 24 h postchallenge. No change was observed in vitamin C concentrations in milk from unchallenged quarters. The concentration of DHAA in milk from challenged quarters increased 67% 24 h postchallenge. The duration of clinical mastitis, peak body temperature, number of colony-forming units of E. coli isolated from the infected gland, and loss in milk yield were associated with a change in concentration of vitamin C in milk from the challenged quarter. Increased severity of clinical signs was associated with large decreases in concentration of vitamin C in milk from the challenged quarter. Similar, but statistically weaker, relationships were observed for changes in plasma vitamin C concentrations.

Nutrition and respiratory health in adults: findings from the health survey for Scotland.

There is a growing body of evidence to support the hypothesised links between consumption of antioxidant rich foods and the occurrence of obstructive airway disease. The main research question was to examine the relationships between two types of dietary exposure and two indicators of respiratory morbidity in Scottish adults. The relationships between dietary consumption of fruit, vegetables and fish, and plasma levels of vitamins A, C, E and beta-carotene, and pulmonary function (forced expiratory volume in one second (FEV1)) and symptoms (phlegm production and shortness of breath with wheezing), were examined in a random population sample of adults. A dose/response relationship was found between fruit consumption and pulmonary function. In comparison with eating fruit rarely or never, eating fruit at least once per day, 1-6 times per week, and 1-3 times per month were associated with differences of 132, 100 and 63 mL in FEV1, after adjustment for known confounders and dietary intake of vegetables and fish (n=6186). An SD score change in plasma vitamin C was associated with a 49 mL difference in FEV1 (n=930). Fruit and vitamin E were associated with a reduced prevalence of phlegm production for 3 months or more per year. The most beneficial combination of dietary components may be found in natural foodstuffs, particularly fresh fruit.

A Spread Enriched with Plant Sterol-Esters Lowers Blood Cholesterol and Lipoproteins without Affecting Vitamins A and E in Normal and Hypercholesterolemic Japanese Men and Women

The objective of the study was to investigate whether different initial baseline cholesterol levels modulate the efficacy of a spread enriched with plant sterol-esters (PS) in lowering blood cholesterol in a Japanese population consuming their usual diet. Healthy adults with a mean age of 45 y and mean plasma total cholesterol (TC) level of 6.5 mmol/L were recruited to participate in a double-blind trial comprised of a run-in period of 1 wk, followed by two intervention periods of 3 wks in a 2 x 2 crossover design and a post-trial follow-up of 3 wk. Volunteers consumed two spreads, one enriched with PS (12 g/100 g plant sterols) and a control spread not fortified with PS. Recommended spread intake was 15 g/d. Effects on plasma lipids, lipoproteins, beta-carotene and vitamins A and E were assessed. Plasma TC and LDL cholesterol (LDL-C) concentrations were 5.8 and 9.1% lower, respectively, when subjects consumed the PS spread than when they consumed the control spread (P < 0.001). Subjects were divided into two groups [normal and mildly cholesterolemic (TC <5.7 mmol/L) and hypercholesterolemic (TC >/= 5.7 mmol/L)]. Reductions (P < 0.001) in TC and LDL-C due to treatment in the former group were 4.9 and 7.9%, respectively. In the hypercholesterolemic group, the reductions (P < 0.001) were 7.1 and 10.6%, respectively. The decreases did not differ between normal/mildly cholesterolemic and hypercholesterolemic subjects. Plasma apolipoprotein B (apoB) and remnant-like particle (RLP) cholesterol (RLP-C) concentrations were lower when subjects consumed the PS spread (44.3 g/L) than the control spread (49.7 g/L). Plasma beta-carotene concentration was lower (P < 0.001) in subjects consuming the PS spread than in the control. Changes in plasma vitamins A and E levels did not differ after intake of the PS and control spreads. In conclusion, consumption of a PS-enriched spread effectively lowered plasma TC, LDL-C, apoB and RLP-C regardless of baseline plasma TC at an intake of 1.8 g/d of plant sterols.

Vitamin B-12 Status Is Inversely Associated with Plasma Homocysteine in Young Women with C677T and/or A1298C Methylenetetrahydrofolate Reductase Polymorphisms

Methylenetetrahydrofolate reductase (MTHFR) polymorphisms may negatively influence one-carbon metabolism and increase health risks in women of reproductive age. The effect of MTHFR single nucleotide polymorphisms at bp 677 and/or 1298 and differences in folate and vitamin B-12 status on plasma homocysteine concentration in women of reproductive age (20-30 y; n = 186) were investigated. From the multivariate regression model, homozygotes (n = 23) for the C677T MTHFR variant had plasma homocysteine concentrations that were higher (P < 0.05) than those observed in the other 5 genotype groups, including those who were heterozygous for both variants (677CT/1298AC; n = 32). Plasma homocysteine was negatively associated with plasma vitamin B-12 concentration (P = 0.015) and serum folate (P = 0.049), with the degree of correlation between plasma vitamin B-12 and homocysteine concentrations dependent on MTHFR genotype. The C677T and A1298C MTHFR polymorphisms were significant predictors (P < 0.05) of plasma homocysteine when regression analysis was used to model plasma homocysteine concentration as a function of genotype, supplement use, serum folate and plasma vitamin B-12 concentration. Plasma homocysteine decreased as vitamin B-12 concentration increased (P = 0.0005) in individuals who were heterozygous for both the C677T and A1298C variants with nonsignificant trends (P = 0.114-0.128) in individuals homozygous for either the C677T or A1298C variants. In contrast, within the group of individuals with the wild-type genotype for both the C677T and A1298C MTHFR variants, homocysteine was not associated with changes in plasma vitamin B-12 concentrations. These data suggest that enhancing vitamin B-12 status may significantly decrease homocysteine in young women with C677T and/or A1298C MTHFR polymorphisms, even when vitamin B-12 concentrations are within the normal range.