Dietary Ascorbic Acid Research Articles

Combined Effects of Butyl Hydroxytoluene and Vitamin C on the Growth Performance, Blood Biochemistry, and Antioxidative Status of Common Carp (Cyprinus Carpio)

Abstract Common carp are proper finfish species for intensification, though their feeds should be reinforced with functional additives to ensure high growth performance and health status. Thus, this study tested the combined effects of butyl hydroxytoluene (BHT) and vitamin C (VC) on the growth performance, blood biomarkers, and antioxidative capacity of common carp. Fish were allotted into four groups and fed on four diets where the control diet was free of VC or/and BHT, while the second and third diets contained dietary VC or BHT at 500 or 150 mg/kg, respectively. The fourth diet was supplemented with both VC (500 mg/kg) and BHT (150 mg/kg) (BHT+VC). After 70 days, feeding VC or/and BHT markedly affected the growth performance of common carp. Carps fed VC, BHT, or BHT+VC had higher (P<0.05) FBW, WG, and SGR than fish fed the control diet, while the FCR was lower (P<0.05) in fish fed both VC and BHT than the control. In addition, feeding BHT or both BHT+VC markedly (P<0.05) reduced the AST, ALT, and urea. The blood protein, albumin, and globulin were higher (P<0.05) in fish fed VC or/and BHT than in the control. Fish fed dietary VC, or BHT+VC, had lower (P<0.05) total cholesterol (T-CHO) and triglycerides (TG) than those fed on the control or BHT. The SOD, CAT, and GPX were significantly higher (P<0.05) in carp fed on dietary VC or/and BHT than in fish fed on the control diet. Nevertheless, the malondialdehyde level was lower (P<0.05) in carp fed on VC or BHT+VC diets than fish on the control or BHT diets. The lysozyme activity was significantly higher (P<0.05) in carp fed on the BHT+VC diet than in the control or VC. In conclusion, the study suggests that dietary BHT or/and VC can be added to the diets of common carp to enhance the growth performance, feed digestion, blood biomarkers, and antioxidative capacity.

Dietary vitamin C reduces mortality of pacific white shrimp (Penaeus vannamei) post-larvae by Vibrio parahaemolyticus challenge

This study was conducted to investigate whether optimal vitamin C (VC) levels can enhance non-specific immune response and antioxidant capacity and reduce mortality of Pacific white shrimp (Penaeus vannamei) post-larvae when infected with Vibrio parahaemolyticus. Six experimental diets were formulated to contain six different VC levels of 0, 40, 80, 120, 160 and 320 mg/kg diet (designated as C0, C40, C80, C120, C160 and C320, respectively). Shrimp post-larvae (39.1 ± 0.47 mg) were randomly distributed to 24 tanks with 40 shrimp per tank. Four replicate groups of shrimp were fed one of the diets for 43 days. VC supplemented groups showed significantly higher growth performance than C0 group. Shrimp fed C120 diet had significantly improved feed utilization efficiency than shrimp fed C0 diet. VC concentrations in hepatopancreas and gills were significantly higher with the increase in dietary VC levels. Optimal dietary VC levels significantly upregulated the expressions of growth and digestive enzyme-related genes such as IGF-1, IGF-BP, amylase, trypsin and chymotrypsin, and also upregulated the expressions of innate immunity and antioxidant-related genes such as prophenoloxidase, crustin, penaiedin-3a, superoxide dismutase, glutathione peroxidase and catalase in hepatopancreas. Shrimp fed C80, C120 and C160 diets showed significantly increased resistance to V. parahaemolyticus than shrimp fed C0 diet. The optimum dietary VC level for the shrimp post-larvae was established to be 80.2 mg/kg diet by a broken-line regression analysis based on the growth. The findings from the challenge test indicated that VC levels over 83.0 mg/kg diet could enhance disease resistance of the shrimp against V. parahaemolyticus.

Conservation of a Chromosome 8 Inversion and Exon Mutations Confirm Common Gulonolactone Oxidase Gene Evolution Among Primates, Including H. Neanderthalensis

Ascorbic acid functions as an antioxidant and facilitates other biochemical processes such as collagen triple helix formation, and iron uptake by cells. Animals which endogenously produce ascorbic acid have a functional gulonolactone oxidase gene (GULO); however, humans have a GULO pseudogene (GULOP) and depend on dietary ascorbic acid. In this study, the conservation of GULOP sequences in the primate haplorhini suborder were investigated and compared to the GULO sequences belonging to the primates strepsirrhini suborder. Phylogenetic analysis suggested that the conserved GULOP exons in the haplorhini primates experienced a high rate of mutations following the haplorhini/strepsirrhini divergence. This high mutation rate has decreased during the evolution of the haplorhini primates. Additionally, indels of the haplorhini GULOP sequences were conserved across the suborder. A separate analysis for GULO sequences and well-conserved GULOP sequences focusing on placental mammals identified an in-frame GULO sequence in the Brazilian guinea pig, and a potential GULOP sequence in the pika. Similar to haplorhini primates, the guinea pig and lagomorph species have experienced a high substitution rate when compared to the mammals used in this study. A shared synteny to examine the conservation of local genes near GULO/GULOP identified a conserved inversion around the GULO/GULOP locus between the haplorhini and strepsirrhini primates. Fischer’s exact test did not support an association between GULOP and the chromosomal inversion. Mauve alignment showed that the inversion of the length of the syntenic block that the GULO/GULOP genes belonged to was variable. However, there were frequent rearrangements around ~ 2 million base pairs adjacent to GULOP involving the KIF13B and MSRA genes. These data may suggest that genes acquiring deleterious mutations in the coding sequence may respond to these deleterious mutations with rapid substitution rates.

Ascorbic acid biosynthesis in Pacific abalone Haliotis discus hannai Ino and L-gulonolactone oxidase gene loss as an independent event

Up to now, it has been believed that invertebrates are unable to synthesize ascorbic acid (AA) in vivo. However, in the present study, the full-length CDs (Coding sequence) of L-gulonolactone oxidase (GLO) from Pacific abalone (Haliotis discus hannai Ino) were obtained through molecular cloning. The Pacific abalone GLO contained a FAD-binding domain in the N-termination, and ALO domain and conserved HWAK motif in the C-termination. The GLO gene possesses 12 exons and 11 introns. The Pacific abalone GLO was expressed in various tissues, including the kidney, digestive gland, gill, intestine, muscle and mantle. The GLO activity assay revealed that GLO activity was only detected in the kidney of Pacific abalone. After a 100-day feeding trial, dietary AA levels did not significantly affect the survival, weight gain, daily increment in shell length, and feed conversion ratio of Pacific abalone. The expression of GLO in the kidney was downregulated by dietary AA. These results implied that the ability to synthesize AA in abalone had not been lost. From the evolutionary perspective, the loss of GLO occurred independently as an independent event by matching with the genomes of various species. The positive selection analysis revealed that the GLO gene underwent purifying selective pressure during its evolution. In conclusion, the present study provided direct evidence to prove that the GLO activity and the ability to synthesize AA exist in abalone. The AA synthesis ability in vertebrates might have originated from invertebrates dating back 930.31 million years.

Vitamin C Alleviates Intestinal Inflammation Caused by Aeromonas hydrophila in Juvenile Blunt Snout Bream (Megalobrama amblycephala)

Vitamin C (VC) can be used to increase disease resistance in practice in intensive aquaculture. But it is still unconfirmed whether VC could alleviate inflammation and what dosage is suitable. This study investigated the effects of dietary VC on the immunity and enteritis of juvenile blunt snout bream (Megalobrama amblycephala) challenged with Aeromonas hydrophila. The fish were fed with VC levels ranging from 25.35 to 2231.98 mg/kg for 60 days. After that, fish fed with 150.65 mg/kg, 573.79 mg/kg, and 2231.98 mg/kg VC were challenged with A. hydrophila orally to simulate enteritis. The results showed that 285.39 and 573.79 mg/kg dietary VC significant improved growth performance and feed utilization. Dietary VC (573.79 and 1133.79 mg/kg) significantly enhanced the serum immune parameters, antioxidant enzymes’ activities, and relative gene expressions of ikbα and cat in the liver in the 60-day feeding trail. The survival rate was significantly higher in 573.79 mg/kg dietary VC group than the other two treatments. Cytokines were activated after the bacteria challenge. Dietary 573.79 mg/kg VC caused significantly higher TNF-α level at 12 hpi and maintained a high level of IL-8 at 48 to 72 h compared to other treatments. In conclusion, more than 500 mg/kg VC was needed to maintain the health of blunt snout bream juveniles. Suitable VC would activate cytokines to increase disease resistance along with antioxidant enzymes.

Effect of Dietary Vitamin C Supplementation on Growth Performance and Biochemical Parameters in Grower Walleye Pollock, Gadus chalcogrammus.

The optimal dietary vitamin C (VC) levels for walleye pollock (Gadus chalcogrammus) remain undefined. This study aimed to assess the effect of dietary VC levels on the growth performance and biochemical parameters of grower walleye pollock and determine the optimal VC level for their diet. Six experimental diets (VC0, VC1, VC3, VC5, VC7, and VC10) with VC levels of 3.24, 21.92, 63.31, 101.42, 145.46, and 202.51 mg kg-1 diet, respectively, were fed to fish (initial mean weight: 173.5 ± 0.31 g) for 8 weeks. At the end of the feeding trial, fish fed the VC7 and VC10 diets exhibited significantly higher growth (final body weight, weight gain, and specific growth rate) and improved feed utilization (feed efficiency and protein efficiency ratio) compared with fish fed the VC0 diet (p < 0.05). The VC3-VC10 diets significantly reduced plasma superoxide dismutase (SOD) activity (p < 0.05). Compared with the VC0 group, fish fed the VC7 and VC10 diets showed significantly elevated growth hormone and insulin-like growth factor-1 levels in plasma (p < 0.05). In conclusion, dietary VC supplementation in walleye pollock improved growth performance and SOD activity. Moreover, broken-line analysis on weight gain indicated that the optimal dietary VC level for grower walleye pollock was approximately 156.42 mg kg-1 diet.

Biological and histological changes and DNA damage in Oreochromis niloticus exposed to oxytetracycline: a potential amelioratory role of ascorbic acid

Antibiotics are crucial in the control of bacterial infections on fish farms. However, the influence of licensed antibiotics on DNA damage, histological changes, and protein differentiation in some farmed fish species is unidentified. The current study aimed to investigate the effect of therapeutic (80 mg/kg body weight/day) and high doses (160 mg/kg body weight/day) of oxytetracycline (OTC) on some biological indices, protein differentiation, histological changes, and DNA damage in Oreochromis niloticus (n = 360; 40 ± 3.5 g) and the potential positive effects of dietary ascorbic acid (AA) and whether it is capable of reducing the deleterious impacts of OTC and working synergistically to increase fish disease resistance and decrease morbidity and mortality rates. In the current study, fish were fed diets with or without OTC (80 or 160 mg/kg body weight/day) and AA (100 mg/kg diet/day) for 28 days, followed by a bacterial stress test with two different virulent strains for 14 days. Treatments include CTR (control; without additives), AA, OTC80, OTC160, OTC80 + AA, and OTC160 + AA. The results revealed that the AA group had the best antioxidative (significant increase in SOD, CAT, and GPx) and immunomodulatory effects (an increase in IgM, nitroblue tetrazolium, and total leucocytic count). Furthermore, the hematological parameters, immune indices (NBT), and antioxidant enzymes were significantly reduced by OTC160 (p ≤ 0.05). The results also showed that OTC160 notably augmented the activity of liver (ALT, AST, and LDH) and kidney (creatinine and urea) damage markers (p ≤ 0.05). OTC160 revealed considerable hepatic and renal tissue damage and significantly higher hepatocyte DNA damage. Pathological changes and DNA damage were directly correlated to the dosage of OTC exposure, where they were more severe in OTC160. OTC80 showed insignificant changes in most parameters. Compared to CTR, the inclusion of AA in the O. niloticus diet significantly restored the biological indices, histological changes, and DNA damage in OTC-treated groups. The morbidity and mortality percentages after bacterial challenge were significantly lower in the OTC80 + AA group, followed by the OTC160 + AA group than in the CTR. These results corroborate the use of AA as a potent antioxidant and immune stimulant and a potential co-adjuvant to OTC in the diet of O. niloticus to reach optimal resistance to disease.

Effects of Daily Ingestion of Two SunGold Kiwifruit for 6 Weeks on Metabolic and Inflammatory Biomarkers: A Randomized, Cross-Over, Exploratory Intervention Study.

Kiwifruit contain many components, some considered beneficial, such as vitamins, phytochemicals and dietary fibre, and others potentially harmful, such as fructose and glucose in fruit sugars. In a 6-week, randomised, crossover study aimed at exploring the net effects of daily consumption of kiwifruit, 23 healthy participants consumed two Actinidia chinensis var. chinensis 'Zesy002' (marketed as Zespri™ SunGold™ Kiwifruit) per day as part of their customary diet (intervention) or without kiwifruit (control) as their customary diet for 6 weeks in a cross-over study. Anthropometric data, venous blood, and urine samples were collected at the start and end of the 6-week intervention and control periods for the measurement of physical changes, plasma glucose, insulin, glycated haemoglobin, short-chain fatty acids, blood lipids, uric acid, inflammatory biomarkers, and urinary ascorbic acid. Variables were measured between the start and finish of interventions, and between intervention and control periods. Food diaries were completed on the 3 days before blood sampling to estimate dietary ascorbic acid and dietary fibre intakes. Despite urinary vitamin C and food diaries indicating compliance, and good precision in measurements, there were no appreciable changes in biomarkers during the study, either within or between intervention and control periods, that would indicate a change in health status. Thus, the sizes of any effects of kiwifruit ingestion were too small to become significant under the test conditions used, indicating a high probability that daily ingestion of two SunGold kiwifruit is safe with respect to metabolic health.

Production performance, haematological parameters, serum biochemistry, and expression of HSP-70 in broiler chickens fed dietary ascorbic acid during heat stress.

An experiment was carried out to assess the efficacy of supplemental ascorbic acid (AA) on broiler chicken production performance, blood haematological profile, biochemical profile, and carcass traits under heat stress conditions. A total of 192-day-old broiler chicks were divided into four groups, each with six replicates of eight each (4 × 6 × 8). Four corn-based dietary treatments were formulated: T1 (control diet), T2 (T1 + AA at 200mg/kg), T3 (T1 + AA at 400mg/kg), and T4 (T1 + AA at 600mg/kg) for a period of 42days. Despite the high temperature and humidity, the 600mg AA supplemental groups (T4) gained significantly (P ≤ 0.05) more body weight and had a higher feed intake and better feed conversion ratio (FCR) than the control group (T1). After 28days of feeding the three AA-supplemented diets, antibody titres (humoral immune response) were significantly higher (P ≤ 0.05). The response to intradermally injected phyto-haemagglutinin (PHA-P), an index of the in vivo cell-mediated immune response, was found to be increased (P ≤ 0.05) in the 400 and 600mg AA-supplemented groups after 35days. Higher levels of AA (T4) supplementation significantly (P ≤ 0.05) improved haematological values such as haemoglobin (Hb), total erythrocyte count (TEC), total leukocyte count (TLC), and differential leukocyte count (DLC), heterophil:lymphocyte (H:L) in comparison to the control group (T1). The supplemented group improved the serum biochemical profile of the birds, with an increase (P ≤ 0.05) in total serum protein, albumin, and globulin and a decrease in serum cholesterol and corticosterone levels in the T4 group compared to the control group. Heat shock protein-70 (HSP-70) was gradually elevated after increasing the ascorbic acid concentration (P ≤ 0.05) at 14 and 21days. As a result, it can be concluded that supplementing ascorbic acid at 600mg/kg is beneficial for improving the performance, immunity, and blood haematological biochemical profile and upregulating the HSP-70 gene of broiler chickens under heat stress conditions.

Long-Term Low Ascorbic Acid Intake Reduces Bone Mass in Guinea Pigs

The effect of long-term (1 y) low to excess ascorbic acid (AA) intake on bone mass was evaluated using guinea pigs that were 12–14 d old at the start of the experiment. Dietary AA was low (0.15 g/kg diet) (n = 7), normal (0.50 g/kg) (n = 8) or excess (10 g/kg) (n = 8). After 12 mo, total body bone mineral density (BMD, mg/cm2) and bone mineral content (BMC, g) were determined by dual energy X-ray absorptiometry. Histomorphometric analysis of the cancellous bone of the proximal tibial metaphysis was completed after in vivo dual fluorochrome labeling. Total body BMD of the low AA group was 4.9% lower (P < 0.05), and total body BMC was 12.4% lower (P < 0.05) than in the normal AA group. Total body BMD and BMC were similar in normal and excess AA groups and in the low and excess AA groups. Histomorphometric analysis indicated significantly greater (P < 0.05) double-labeled bone surface, mineralizing surface, and bone formation rate in the low AA guinea pigs compared with the normal AA animals. Thus, there was greater bone turnover in the low AA group than in the normal AA guinea pigs. No differences in histomorphometric endpoints existed between the normal AA and excess AA groups. Long-term AA deficiency, during the period of rapid growth and slower phases of skeletal maturation, resulted in bone abnormalities in adult guinea pig skeletons. Long-term dietary AA excess caused no such abnormalities.

Fatal Epileptic Seizures in Mice Having Compromised Glutathione and Ascorbic Acid Biosynthesis.

Reduced glutathione (GSH) and ascorbic acid (AA) are the two most abundant low-molecular-weight antioxidants in mammalian tissues. GclmKO knockout mice lack the gene encoding the modifier subunit of the rate-limiting enzyme in GSH biosynthesis; GclmKO mice exhibit 10-40% of normal tissue GSH levels and show no overt phenotype. GuloKO knockout mice, lacking a functional Gulo gene encoding L-gulono-γ-lactone oxidase, cannot synthesize AA and depend on dietary ascorbic acid for survival. To elucidate functional crosstalk between GSH and AA in vivo, we generated the GclmKO/GuloKO double-knockout (DKO) mouse. DKO mice exhibited spontaneous epileptic seizures, proceeding to death between postnatal day (PND)14 and PND23. Histologically, DKO mice displayed neuronal loss and glial proliferation in the neocortex and hippocampus. Epileptic seizures and brain pathology in young DKO mice could be prevented with AA supplementation in drinking water (1 g/L). Remarkably, in AA-rescued adult DKO mice, the removal of AA supplementation for 2-3 weeks resulted in similar, but more severe, neocortex and hippocampal pathology and seizures, with death occurring between 12 and 21 days later. These results provide direct evidence for an indispensable, yet underappreciated, role for the interplay between GSH and AA in normal brain function and neuronal health. We speculate that the functional crosstalk between GSH and AA plays an important role in regulating glutamatergic neurotransmission and in protecting against excitotoxicity-induced brain damage.

Effects of Dietary Vitamin C on the Growth Performance, Biochemical Parameters, and Antioxidant Activity of Coho Salmon Oncorhynchus kisutch (Walbaum, 1792) Postsmolts.

Vitamin C (VC) plays an essential role in fish physiological function and normal growth. However, its effects and requirement of coho salmon Oncorhynchus kisutch (Walbaum, 1792) are still unknown. Based on the influences on growth, serum biochemical parameters, and antioxidative ability, an assessment of dietary VC requirement for coho salmon postsmolts (183.19 ± 1.91 g) was conducted with a ten-week feeding trial. Seven isonitrogenous (45.66% protein) and isolipidic (10.76% lipid) diets were formulated to include graded VC concentrations of 1.8, 10.9, 50.8, 100.5, 197.3, 293.8, and 586.7 mg/kg, respectively. Results showed that VC markedly improved the growth performance indexes and liver VC concentration, enhanced the hepatic and serum antioxidant activities, and increased the contents of serum alkaline phosphatase (AKP) activity, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and total cholesterol (TC) whereas decreased the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) activities, and triglyceride (TG) level. Polynomial analysis showed that the optimal VC levels in the diet of coho salmon postsmolts were 188.10, 190.68, 224.68, 132.83, 156.57, 170.12, 171.00, 185.50, 142.77, and 93.08 mg/kg on the basis of specific growth rate (SGR), feed conversion ratio (FCR), liver VC concentration, catalase (CAT), hepatic superoxide dismutase (SOD) activities, malondialdehyde (MDA) content, and serum total antioxidative capacity (T-AOC), AKP, AST, and ALT activities, respectively. The dietary VC requirement was in the range of 93.08-224.68 mg/kg for optimum growth performance, serum enzyme activities, and antioxidant capacity of coho salmon postsmolts.

Evaluation of dietary Vitamin C requirement of Hypophthalmichthys molitrix fingerlings and its effects on growth, haematology and serum enzyme activities

Vitamin C (VC) is a necessary nutrient for normal fish physiology and immunity. Therefore, A 60-day feeding trial was designed to evaluate the dietary VC requirements of silver carp (Hypophthalmichthys molitrix). Six isocaloric and isonitrogenous diets were formulated by incorporation of VC at 0, 50, 100, 200, 400 and 800 mg kg−1 levels and the analysed VC content in diet was 5.7, 51.1, 95.3, 191.6, 370.7 and 757.5 mg kg−1 respectively. At the trial termination, VC supplementation significantly enhanced the growth and feed utilization. The highest values for whole body crude protein were recorded at 95.3 and 191.6 mg kg−1 of VC. In comparison to the basal diet, VC supplementation improved (p < 0.05) the whole body crude fat. Dietary VC had a dose-dependent effect on the white blood cell count and haematocrit. A significant increase in the alkaline phosphatase activity was recorded for fish fed 5.7 to 95.3 mg kg−1 of VC, attaining a constant value afterwards (95.3–757.5 mg kg−1 of VC). In comparison, dietary VC decreased (p < 0.05) the aspartate aminotransferase and alanine aminotransferase activities. Similarly, the glucose content also decreased significantly from 5.7 to 95.3 mg kg−1 of VC and became constant thereafter. Dietary VC supplementation significantly affected the antioxidant enzyme activities. The liver VC content showed a dose-dependent relation, where the VC content increased with the increase in VC supplementation reaching the highest value at 757.5 mg kg−1. Moreover, VC-fed fish showed an increased (p < 0.05) survival against Aeromonas hydrophila challenge. On the basis of broken-line regression, the optimum dietary VC requirement of H. molitrix for weight gain% and liver VC content is 61.31 and 241.13 mg kg−1 respectively.

Efficacy of ascorbic acid and different sources of orange peel on growth performance, gene expression, anti-oxidant status and microbial activity of growing rabbits under hot conditions

Orange peel and its extract are good sources of phenols and vitamin C that can be used as powerful antioxidants and antibacterial. The effects of dietary ascorbic acid (AA), orange peel powder (OPP) and orange peel extract (OPE) supplementations on growth performance, blood biochemicals, gene expression and antioxidant status of growing rabbits under hot conditions were investigated. A total of 80 weaned Giant Flander male rabbits, five weeks old (606.25 ± 10.08 g), were randomly assigned to four groups. The first group received untreated diet (control group). The other groups received diets supplemented with 0.5 g AA/kg diet, 2% OPP and 500 mg OPE/kg diet. The lowest feed conversion ratio (FCR) was recorded by rabbits consumed diet supplemented with AA. Supplementations of OPP and OPE reduced blood plasma total cholesterol, low density lipoprotein and very-low density lipoprotein concentrations. The tested diets reduced triglycerides, total lipids, hydrogen peroxide, malondialdehyde levels, Staphylococcus aureus and Escherichia coli of the rabbits cecum. Supplementation of OPE improved activities of superoxide dismutase gene (6.1475) and insulin-like growth factor-1 (9.2108). Conclusively, dietary supplementation of OPE improved rabbit performance through improving antioxidant enzyme activities as well as upregulation of insulin-like growth gene. Additionally, OPP and OPE (2% and 500 mg/kg diet, respectively) had antibacterial effects for growing rabbits under hot conditions.

A Causal Relationship between Vitamin C Intake with Hyperglycemia and Metabolic Syndrome Risk: A Two-Sample Mendelian Randomization Study.

Excessive oxidative stress can contribute to metabolic syndrome (MetS), and antioxidants can protect against its development. Vitamin C (VC) is a well-known antioxidant, and observational studies have associated a deficiency with an increased MetS risk. This study tested the hypothesis that dietary VC intake caused an inverse relation of MetS and its components risk using a two-sample Mendelian randomization (MR) method in adults ≥40 years in a city hospital-based (n = 58,701) and Ansan/Ansung plus rural (n = 13,598) cohorts. Independent genetic variants associated with dietary VC intake were explored using a genome-wide association study (GWAS) with significance levels of p < 5 × 10−5 and linkage disequilibrium (r2 threshold of 0.001), after adjusting for the covariates related to MetS, in a city hospital-based cohort (n = 52,676) excluding the participants having vitamin supplementation. MR methods, including inverse-variance weighting (IVW), weighted median, MR-Egger, and weighted model, were used to determine the causal relationship between the dietary VC intake and the risk of MetS and its components in Ansan/Ansung plus rural cohorts (n = 11,733). Heterogeneity and leave-one-out sensitivity analyses were conducted. Energy intake, as well as other nutrient intakes, were significantly lower in the low VC intake group than in the high VC intake group, but the incidence of MetS and its components, including hyperglycemia, hypertriglyceridemia, and hypertension, was observationally higher in inadequate low VC intake in the combined cohorts. In MR analysis, insufficient dietary VC intake increased the risk of MetS, hyperglycemia, hypertriglyceridemia, and hypertension in an IVW (p < 0.05). In contrast, only the serum fasting blood glucose concentration was significantly associated with VC intake in weight median analysis (p < 0.05), but there was no significant association of low dietary VC with MetS and its components in MR-Egger. There was no likelihood of heterogeneity and horizontal pleiotropy in MetS and its components. A single genetic variant did not affect their association in the leave-one-out sensitivity analysis. In conclusion, insufficient dietary VC intake potentially increased the MetS and hyperglycemia risk in Asian adults. Low VC intake can contribute to increasing type 2 diabetes incidence in Asians.

The Association of Dietary Vitamin Intake Time Across a Day With Cardiovascular Disease and All-Cause Mortality.

BackgroundChrono-nutrition emphasized the importance of the intake time; however, less is known about the impact of dietary vitamin intake time on health. This study aimed to examine our hypothesis about which vitamin intake time could influence the natural course of cardiovascular disease (CVD).MethodsA total of 27,455 adults enrolled in the National Health and Nutrition Examination Survey (NHANES) during 2003–2014 were recruited. The 12 dietary vitamin intakes in the morning, afternoon, and evening were categorized into tertiles or quartiles. Cox-proportional hazard regression models were developed to evaluate the association of vitamin intake time with CVD and all-cause mortalities.ResultsCompared with participants in the lowest quartile, participants in the highest quartile of dietary VB2 intake in the morning had significantly lowest mortality risk of CVD [hazard ratio (HR)VB2 = 0.75, 95% CI: 0.60–0.94, p = 0.017]; whereas, participants in the highest quartile of dietary-vitamin B6 (VB6), vitamin C (VC), vitamin E (VE), and folate-equivalent consumed in the evening showed the lowest risks of CVD (HRVB6 = 0.77, 95% CI: 0.60–0.99, p = 0.103; HRVC = 0.80, 95% CI: 0.65–0.98, p = 0.050; HRVE = 0.75, 95% CI: 0.56–0.99, p = 0.032; HRfolate–equivalent = 0.78, 95% CI: 0.63–0.97, p = 0.116) and all-cause mortalities (HRVB6 = 0.81, 95% CI: 0.71–0.93, p = 0.006; HRVC = 0.85, 95% CI: 0.76–0.95, p = 0.004; HRVE = 0.84, 95% CI: 0.72–0.97, p = 0.011; HRfolate–equivalent = 0.80, 95% CI: 0.71–0.90, p = 0.001). Moreover, equivalently replacing 10% intake of dietary VB6, VC, VE, and folate-equivalent in the morning with evening were associated with 4% (HRVB6 = 0.96, 95% CI: 0.92–0.99), 5% (HRVC = 0.95, 95% CI: 0.92–0.99), 4% (HRVE = 0.96, 95% CI: 0.91–0.99), and 5% (HRfolate–equivalent = 0.95, 95% CI: 0.92–0.99) lower risk of CVD mortality.ConclusionThis study found that the optimal intake time of dietary VB2 was in the morning, and the optimal intake times of dietary VB6, VC, VE, and folate-equivalent were in the evening.

Interactions of dietary eicosapentaenoic acid and vitamin C on growth performance, anti-oxidation and muscle quality of abalone Haliotis discus hannai Ino

A 93-day feeding trial was conducted to investigate the effects of dietary eicosapentaenoic acid (EPA) and vitamin C (VC) on the growth performance, anti-oxidation and muscle quality of abalone Haliotis discus hannai (initial body weight: 26.89 ± 0.26 g; initial shell length: 60.36 ± 0.25 mm). Six experimental diets in a 3 × 2 two-factor design were formulated with graded levels of dietary EPA (0.25%, 0.75% and 1.25%) and dietary VC (0 and 1260 mg/kg). Results showed that the weight gain rate (WGR) of abalone was significantly increased with the increasing dietary EPA levels (P < 0.05), but there was no significant effect of dietary VC on the WGR. The significant highest superoxide dismutase (SOD) activity was observed in the group with 1.25% of dietary EPA and 1260 mg/kg of dietary VC, and there was a significant interaction between dietary EPA and VC (P < 0.05). Dietary EPA supplementation significantly improved muscle hardness and the content of ∑n-3 polyunsaturated fatty acids, volatile compounds, adenosine-5′-monophosphate (AMP) and inosine-5′-monophosphate (IMP) in muscle. Dietary VC supplementation significantly improved the muscle hardness, springiness, chewiness, and the contents of volatile compounds, hydroxyproline and IMP in muscle (P < 0.05). Significant interactions between dietary EPA and VC were observed on volatile compounds, AMP and IMP (P < 0.05). In conclusion, dietary EPA and VC interactively influence the anti-oxidative capability and muscle quality of abalone.

Effects of dietary vitamin C, thyme essential oil, and quercetin on the immunological and antioxidant status of common carp (Cyprinus carpio)

Nowadays, natural bioactive substances are a used in aquaculture feeds to improve fish welfare and therefore increase the quality and sustainability of fish production. The present study was conducted to compare the effects of dietary vitamin C (VC), thyme essential oil (TE), and quercetin (QR) levels on the hematology, and antioxidant and immune parameters of common carp, Cyprinus carpio. Four hundred twenty fish (20.46 ± 0.07 g) were distributed randomly into seven experimental groups (assayed in triplicates). The experimental diets were formulated as follows: CON (0, control); VCL (500 mg VC/kg); VCH (1000 mg VC/kg); TEL (10 g TE/kg); TEH (20 g TE/kg); QRL (200 mg QR/kg); and QRH (800 mg QR/kg). At the end of the 60-day feeding trial, an increase in white blood cells (WBC) was recorded in the treatment groups compared to that of the control (P < 0.05). Hemoglobin (Hb) and mean corpuscular hemoglobin concentration (MCHC) were significantly affected by the TE treatments (P < 0.05). Fish fed the QR diets presented higher levels of hematocrit (Hct) (P < 0.05); as well as enhanced serum and liver antioxidant capacities; such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) (P < 0.05). Malondialdehyde (MDA) activity was significantly lower in fish fed dietary additives (P < 0.05). The treated groups showed significant improvements in serum and intestine immune parameters lysozyme (LYZ), alternative complement pathway (ACH50), total immunoglobulin (Ig), respiratory burst activity (RBA), and myeloperoxidase (MPO) (P < 0.05). Additionally, serum and liver enzyme parameters such Alanine transaminase (ALT), alkaline phosphatase (ALP), and aspartate transaminase (AST) in fish fed the experimental diets were significantly lower than that of fish fed the control diet (P < 0.05). Dietary supplementations had progressive effects on skin mucus LYZ, protease, ALP, Ig, ACH50, and total protein (TP) levels than the untreated group (P < 0.05). The experiment herein successfully demonstrated that dietary VC, TE, and QR stimulate fish antioxidant capacity, as well as humoral and mucosal immune responses, and can be recommended as beneficial feed additives for common carp.

The ameliorative role of ascorbic acid against blood disorder, immunosuppression, and oxidative damage of oxytetracycline in rainbow trout (Oncorhynchus mykiss)

This experiment was aimed to determine the possible beneficial effects of dietary ascorbic acid (AA) on hematological indices, immune responses, and antioxidative capacity of Oncorhynchus mykiss treated with antibiotic oxytetracycline (OTC). A total of 150 fish were divided evenly among five experimental groups (30 fish of each, in 3 replicates) receiving diets containing OTC (0 and 100mg per kg fish weight) and AA (100, 200, 400, and 800mg per kg fish diet) for 28days. Treatments include group A or control (100mg AA without OTC), group B (100mg AA with OTC), group C (200mg AA with OTC), group D (400mg AA with OTC), and group E (800mg AA with OTC). The results obtained showed that the hematological indices (red blood cells, white blood cells, hematocrit, hemoglobin, and neutrophils), immunological parameters (plasma lysozyme, plasma complement, and skin mucus alkaline phosphatase activities), and antioxidant enzymes activities (superoxide dismutase and catalase) were significantly decreased by OTC in O. mykiss fed control diet (P < 0.05). The results also revealed that OTC significantly increased the activity of biochemical enzymes (aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) in the plasma of O. mykiss fed control diet (P < 0.05). However, in comparison to the control diet, feeding fish with higher amounts of AA (400 and 800mg/kg diet) significantly restored the hematological, immunological, and antioxidative responses in OTC-treated groups (p < 0.05). These findings show that the dietary supplementation of AA at 400 or 800mg/kg diet is beneficial in relieving O. mykiss from OTC-induced oxidative stress and immunosuppression.

Ascorbic acid intake is inversely associated with prevalence of depressive symptoms in US midlife women: A cross-sectional study

BackgroundWith the endocrine changes in menopausal transition period, associations between dietary ascorbic acid intake and depressive symptoms may be different. This investigation examined cross-sectional relations between dietary ascorbic acid intake of women and prevalence of depressive symptoms. MethodsThis is a secondary analysis performed on a subsample of the Study of Women's Health Across the Nation (SWAN). Women enrolled had measures of CES-D depression scores and ascorbic acid intake. Regression models were used to study cross-sectional associations between ascorbic acid intake and depressive symptoms. ResultsA total of 3088 women aged 42–52 years at baseline were included in the present study. Dietary ascorbic acid intake was inversely associated with depressive symptoms. The adjusted OR and 95% CI of depressive symptoms was 0.699 (0.524 – 0.934) in quartile 4 (the highest) versus quartile 1 (the lowest) of the ascorbic acid intake. Restricted cubic spline analyze showed a suggestion of L-shaped associations between ascorbic acid intake and depressive symptoms. ConclusionsAscorbic acid intake is inversely associated with prevalence of depressive symptoms in midlife women. Future prospective cohort studies are needed to confirm these findings.