Dietary Ascorbic Acid Research Articles

Developmental response of the beneficial predator Podisus maculiventris to change in dietary ascorbic acid concentration

We report here the effects of a range of ascorbic acid concentrations (0.07, 0.3, 3.0, and 30.0 g l−1) in artificial diets on growth rates, adult weights, fecundity, and survival over two generations of the predatory stink bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae). Overall, a dietary level of 3.0 g l−1 gave the shortest developmental times over two generations. The likelihood of egg hatch at one ascorbic acid concentration compared to another concentration suggested that egg hatch increased as the concentration of ascorbic acid increased from 0.07 to 3.0 g l−1 and then declined from 3.0 to 30.0 g l−1. The combination of the maximum egg oviposition at 0.3 and 3.0 g l−1, egg hatch at 3.0 g l−1, and survival at 0.07 and 0.3 g l−1 suggests an overall superior performance at a concentration between 0.3 and 3.0 g l−1. Depletion of ascorbic acid below 3.0 g l−1 or addition of ascorbic acid above 3.0 g l−1 lowered the likelihood of egg hatch, which became more pronounced in the second generation. This is consistent with previously published information for phytophagous insects.

Bioactive Dietary Polyphenols Inhibit Heme Iron Absorption in a Dose‐Dependent Manner in Human Intestinal Caco‐2 Cells

Although heme iron is an important form of dietary iron, its intestinal absorption mechanism remains elusive. Our previous study revealed that (-)-epigallocatechin-3-gallate (EGCG) and grape seed extract (GSE) markedly inhibited intestinal heme iron absorption by reducing the basolateral iron export in Caco-2 cells. The aim of this study was to examine whether small amounts of EGCG, GSE, and green tea extract (GT) could inhibit heme iron absorption, and to test whether the inhibitory action of polyphenols could be offset by ascorbic acid. A heme-⁵⁵Fe absorption study was conducted by adding various concentrations of EGCG, GSE, and GT to Caco-2 cells in the absence and presence of ascorbic acid. Polyphenolic compounds significantly inhibited heme-⁵⁵Fe absorption in a dose-dependent manner. The addition of ascorbic acid did not modulate the inhibitory effect of dietary polyphenols on heme iron absorption when the cells were treated with polyphenols at a concentration of 46 mg/L. However, ascorbic acid was able to offset or reverse the inhibitory effects of polyphenolic compounds when lower concentrations of polyphenols were added (≤ 4.6 mg/L). Ascorbic acid modulated the heme iron absorption without changing the apical heme uptake, the expression of the proteins involved in heme metabolism and basolateral iron transport, and heme oxygenase activity, indicating that ascorbic acid may enhance heme iron absorption by modulating the intracellular distribution of ⁵⁵Fe. These results imply that the regular consumption of dietary ascorbic acid can easily counteract the inhibitory effects of low concentrations of dietary polyphenols on heme iron absorption but cannot counteract the inhibitory actions of high concentrations of polyphenols. Bioactive dietary polyphenols inhibit heme iron absorption in a dose-dependent manner. The small amounts of polyphenolic compounds present in foods are capable of reducing heme iron transport across the intestinal enterocyte. However, the inhibitory effects of dietary polyphenolic compounds on heme iron absorption can be offset by ascorbic acid and can possibly be avoided by decreasing the consumption of polyphenols while simultaneously taking ascorbic acid.

Effects of chromium piclonate and ascorbic acid supplementation on growth performance, carcass traits, blood constituents and picture of growing kids under the summer conditions

The present work was performed to study the effect of chromium piclonate and ⁄ or ascorbic acid supplementation on the performance of growing kids during hot summer season (33.6oC and 74.2% RH). A total number of twenty four weaned commercial kids were randomly distributed into four treatment groups of 6 kids per each Kids in all treatments were equal in number and had nearly similar initial body weight. The first group was fed the basal diet and served as control (0.0 supplementation), while the other three groups were fed diets supplemented with 75 mg/kg diet chromium piclonate, 800 mg/ kg diet ascorbic acid and 75 mg / kg diet chromium piclonate + 800 mg ascorbic acid, respectively. The results obtained for growing Kids showed that the final live body weight and daily body gain were increased significantly (P < 0.05 or 0.01) during 210 and 270 daysfor Kids fed diets supplemented with chromium piclonate, ascorbic acid and chromium piclonate + ascorbic acid. However, the supplementation of chromium piclonate + ascorbic acid seemed to be the best significant performance. The results obtained for growing Kids showed that the daily feed intake, feed conversion, water ⁄ feed intake ratio, water ⁄ daily gain ratio were increased significantly (P < 0.05 or 0.01) during the experimental periods for Kids fed diets supplemented with chromium piclonate, ascorbic acid and chromium piclonate + ascorbic acid. The Results showed that water intake, rectum temperature and respiration rate were not significantly affected by previous treatments. The best margin was obtained in group fed on the diet supplemented with chromium piclonate + ascorbic acid. All carcass traits were increased insignificantly due to dietary chromium piclonate and ⁄or ascorbic acid supplementation. Serum total proteins were increased significantly (P < 0.05), in group three only while the cholesterol level and triglycerides decreased significantly (P<0.05) in Kids treated with chromium piclonate as compared with the control group under summer heat stress conditions. Serum albumin, globulin, urea-, creatinine, AST, WBCs, RBCs MCV, MCH and Hb content were insignificantly affected by chromium piclonate and ⁄or ascorbic acid supplementation to the kids’ diets. Finally, it could be concluded that supplementation of 75 mg chromium piclonate + 800 mg ascorbic acid / kg diet to the kid diets is necessary to improve the productivity, under the summer conditions

Imbalanced dietary ascorbic acid alters molecular pathways involved in skeletogenesis of developing European sea bass ( Dicentrarchus labrax)

The influence of dietary ascorbic acid (AA) on growth and morphogenesis during the larval development of European sea bass ( Dicentrarchus labrax) was evaluated until 45 days post hatching. Diets incorporated 0, 5, 15, 30, 50 or 400 mg AA per kg diet to give AA-0, AA-5, AA-15, AA-30, AA-50 and AA-400 dietary treatments, respectively. Dietary AA levels lower than 15 mg/kg reduced larval growth and survival was affected in specimens fed diets devoid of AA. Globally, disruption of the expression of genes involved in AA and calcium absorption in the intestine (SVCT-1, TRPV-6), skeletogenesis (BMP-4, IGF-1, RARγ) and bone mineralization (VDRβ, osteocalcin) were observed in groups fed doses lower and higher than 50 mg AA/kg diet. Such disturbances detected at molecular level were associated with disruptions of the ossification process and the appearance of skeletal abnormalities.

Effect of clipping feathers, dietary ascorbic acid supplementation and season on performance of laying chickens

Feathers may be problematic to chickens in thermoregulation during heat stress. This study was conducted to investigate the effect of clipping feathers, dietary ascorbic acid supplementation and season on performance of laying chickens. 180 ‘Isa Brown’ (IB) layers of about 30 weeks old were subjected to a 2×2×2 factorial combination of feather conditions (intact and clipping), dietary ascorbic acid supplementation (0 and 300 ppm) and season (early dry, ED and late dry, LD) during a trial using a factorial design. The birds were randomly allotted to 8 treatments consisting of treatment one (basal diet and intact feathers); treatment two (basal diet and clipped feathers); treatment three (basal diet supplemented with 300 ppm ascorbic acid and intact feathers) and treatment four (basal diet supplemented with 300 ppm ascorbic acid and clipped feathers) in both ED and LD seasons. Results showed that clipping feathers significantly improved (P 0.05) on HDP, WI, F/Doz., EW, and ESW. However, the effect of the interactions of the three factors were not significant (P>0.05) on FC, EM, EST and %ESW. Finally, clipping of feathers alone; secondly, dietary ascorbic acid supplementation at 300 ppm alone; and thirdly, a combination of the two, can be efficient in condition of heat stress. Key words: Feathers, ascorbic acid, season.

The role of ascorbic acid transporter in the lens of streptozotocin-induced diabetic rat

Ascorbic acid (AA) is found in high concentrations in the lens and protects the lens from photochemical events such as photo-oxidation. Diabetes reduces the concentration of AA in the lens, and it has been suggested that AA supplementation may rescue lens AA in diabetic patients. In the present study, the effects of dietary supplementation with AA were studied to assess changes in AA concentration and AA transporter expression in the lenses of streptozotocin (STZ)-induced diabetic rats. AA was lower in the aqueous humors and lenses of diabetic rats than in control rats, and low AA levels could be normalized with dietary AA supplementation. The sodium-dependent ascorbic acid transporter2, SVCT2, is transporter of AA, and glucose transporter 1 and 3 (GLUT1 and GLUT3) are transporters of dehydroascobic acid. Transcription of GLUT1 and GLUT3 was not changed as a result of diabetes or AA treatment, and the SVCT2 was increased in diabetic rats and normalized by AA supplementation in diabetic rats. Aquaporin 0 (AQP0) expression was increased in diabetic rats and by AA treatment. The rate of AA transport of vesicle originally from diabetic lens and that with AA treatment were greater than that from control rats with or without AA treatment. These results suggest that ascorbates are transported by AQP0 as well as by SVCT2, GLUT1 and GLUT3, and that supplementation with AA may help prevent diabetic cataracts.

Dietary ascorbic acid requirement of cobia, Rachycentron canadum Linneaus

A 10-week feeding trial was conducted to determine the optimal requirement of cobia (Rachycentron canadum Linneaus) for dietary ascorbic acid (AA). Graded levels of L-ascorbyl-2-polyphosphate (LAPP) were supplemented in basal diet to formulate six semi-purified diets containing 2.70 (the control diet), 8.47, 28.3, 80.6, 241 and 733 mg AA equivalent kg−1 diet, respectively. Each diet was randomly fed to triplicate groups of fish in flow-through plastic tanks (300 L), and each tank was stocked with 25 fish with average initial weight of 4.59 ± 0.36 g. Observed deficiency signs included poor growth, higher mortality and lower feeding rate (FR) in the fish of the control group. Fish fed the control diet had significantly lower weight gain (WG), lower feed efficiency ratio (FER) and lower tissue AA concentrations in fish liver and muscle. With the increase of dietary AA, the survival, WG, FER, hepatic and muscular AA concentrations of cobia significantly increased and then levelled off. The dietary AA requirement of cobia was estimated to be 44.7 mg kg−1 based on WG, 53.9 mg kg−1 or 104 mg kg−1 based on either hepatic or muscular AA concentration, respectively.

Effects of δ-aminolevulinic acid and vitamin C supplementation on iron status, production performance, blood characteristics and egg quality of laying hens

An experiment was conducted to evaluate the effects of laying hen diets supplemented with δ-aminolevulinic acid (ALA) and vitamin C (VC) on productive performance, iron status and egg quality. A total of 252 Hy-line brown commercial laying hens were fed two levels of VC (0 and 500 mg/kg) and three levels of ALA (0, 5 and 10 mg/kg) in a 2 × 3 factorial arrangement from 57 to 63 weeks of age. Each treatment contained seven replicates with six hens in each replicate. Supplementation of the diet with both ALA and VC resulted in a significant increase in egg production during 4-6 weeks (p < 0.05). The haematocrit (HCT), total iron-binding capacity (TIBC), white blood cell (WBC), total protein and albumin concentrations were not affected by the dietary treatments. However, ALA and interactive effect of ALA and VC were observed to increase the RBC, haemoglobin and serum iron concentrations (p < 0.05). In addition, inclusion of both ALA and VC increased blood lymphocyte percentage in relation to hens not supplemented with ALA (p < 0.05). Moreover, single effect of ALA or VC improved (p < 0.05) the yolk colour unit and albumin height from 3 to 6 weeks. The egg shell colour was increased (p < 0.05) by the effect of ALA. The addition of VC also led to an increase (p < 0.05) of the Haugh unit at the end of the experiment. However, neither ALA, nor VC exerted an effect on egg weight, egg shell breaking strength or egg shell thickness. The results demonstrate that dietary ALA and VC supplementation can improve the iron status and egg quality of laying hens.

Effects of graded levels of dietary vitamin C on the growth, digestive capacity and intestinal microflora of juvenile Jian carp (Cyprinus carpio var. Jian)

A 60-day experiment was carried out to study the effects of vitamin C [ascorbic acid (AA)] on the growth, digestive enzyme activities and intestinal microbial population. Diets with six levels (0.0, 21.4, 45.1, 69.5, 93.6 and 142.1 mg AA kg−1 diet) of supplemental ascorbyl polyphosphate were fed to juvenile Jian carp (Cyprinus carpio var. Jian) (12.63±0.02 g). The specific growth rate (SGR), feed efficiency and productive protein value were significantly improved with increasing AA levels up to 45.1 mg AA kg−1 diet (P<0.05). The hepatopancreas and muscle AA concentrations were increased with increasing dietary AA levels up to 69.5 and 45.1 mg kg−1 diet respectively (P<0.05). The activities of intestinal trypsin, chymotrypsin, lipase, α-amylase, Na+, K+-ATPase, alkaline phosphatase, gamma-glutamyl transpeptidase and creatinkinase were all positively affected by the AA supplementation (P<0.05). Intestinal Lactobacillus and Bacillus were increased with increasing AA levels up to 45.1 mg AA kg−1 diet (P<0.05), while intestinal Escherichia coli decreased with increasing AA levels up to 45.1 mg AA kg−1 diet (P<0.05). In conclusion, AA improve the digestive capacity and intestinal microbial population of Jian carp, and the dietary AA requirement for SGR of juvenile Jian carp was 40.9 mg AA kg−1 diet.

Interactive effects of dietary vitamin C and phospholipid in micro-bound diet for growth, survival, and stress resistance of larval red sea bream, Pagrus major

This study was conducted to examine the effects of dietary ascorbic acid (AsA) and phospholipid (PL) and their interaction on growth, survival, and stress resistance in red sea bream larvae. Twenty-six days old red sea bream were fed nine micro-bound diets supplemented three levels of AsA (0, 800 and 1600 mg kg−1 diet) and PL (0, 20 and 40 g kg−1 diet) for 15 days. Dietary AsA and PL were both significant factors on survival rates. There was also an interaction between dietary AsA and PL on survival rate (P < 0.05). The larvae fed 800 or 1600 mg kg−1 AsA with 40 g kg−1 PL diets showed the highest survival rate, with values similar to those of the live-food supplemented group. Stress resistance against low salinity exposure significantly increased with increased dietary level of AsA and PL. However, significant interaction of AsA and PL was not detected. The larvae fed 1600 mg kg−1 AsA with 40 g kg−1 PL diet showed the highest stress resistance among all diets, but it was not significantly different than that of larvae fed 800 mg kg−1 AsA with 40 g kg−1 PL diet. This study clearly demonstrated that combined use of AsA and PL can improve survival of 26–40 days posthatching red sea bream larvae. Moreover, the present study suggested that 800 mg kg−1 AsA with 40 g kg−1 PL in diet was needed for producing high quality seedling under the stressful conditions.

The role of ascorbic acid transporter in the lens of streptozotocin-induced diabetic rat

Ascorbic acid (AA) is found in high concentrations in the lens and protects the lens from photochemical events such as photo-oxidation. Diabetes reduces the concentration of AA in the lens, and it has been suggested that AA supplementation may rescue lens AA in diabetic patients. In the present study, the effects of dietary supplementation with AA were studied to assess changes in AA concentration and AA transporter expression in the lenses of streptozotocin (STZ)-induced diabetic rats. AA was lower in the aqueous humors and lenses of diabetic rats than in control rats, and low AA levels could be normalized with dietary AA supplementation. The sodium-dependent ascorbic acid transporter2, SVCT2, is transporter of AA, and glucose transporter 1 and 3 (GLUT1 and GLUT3) are transporters of dehydroascobic acid. Transcription of GLUT1 and GLUT3 was not changed as a result of diabetes or AA treatment, and the SVCT2 was increased in diabetic rats and normalized by AA supplementation in diabetic rats. Aquaporin 0 (AQP0) expression was increased in diabetic rats and by AA treatment. The rate of AA transport of vesicle originally from diabetic lens and that with AA treatment were greater than that from control rats with or without AA treatment. These results suggest that ascorbates are transported by AQP0 as well as by SVCT2, GLUT1 and GLUT3, and that supplementation with AA may help prevent diabetic cataracts.

Differential splenic cytokine responses to dietary immune modulation by diverse chicken lines

Nutritional modulation of the immune system is an often exploited but poorly characterized process. In chickens and other food production animals, dietary enhancement of the immune response is an attractive alternative to antimicrobial use. A yeast cell wall component, beta-1,3/1,6-glucan, augments the response to disease in poultry and other species; however, the mechanism of action is not clear. Ascorbic acid and corticosterone are better characterized immunomodulators. In chickens, the spleen acts both as reservoir and activation site for leukocytes and, therefore, splenic gene expression reflects systemic immune function. To determine effects of genetic line and dietary immunomodulators, chickens of outbred broiler and inbred Leghorn and Fayoumi lines were fed either a basal diet or an experimental diet containing beta-glucans, ascorbic acid, or corticosterone from 56 to 77 d of age. Spleens were harvested, mRNA was isolated, and expression of interleukin (IL)-4, IL-6, IL-18, macrophage inflammatory protein-1beta, interferon-gamma, and phosphoinositide 3-kinase p110gamma transcripts was measured by quantitative reverse transcription PCR. Effects of diet, genetic line, sex, and diet x genetic line interaction on weight gain and gene expression were analyzed. At 1, 2, and 3 wk after starting the diet treatments, birds fed the corticosterone diet had gained less weight compared with birds fed the other diets (P < 0.001). Sex affected expression of IL-18 (P = 0.010), with higher levels in males. There was a significant interaction between genetic line and diet on expression of IL-4, IL-6, and IL-18 (P = 0.021, 0.006, and 0.026, respectively). Broiler line gene expression did not change in response to the experimental diet. Splenic expression of IL-6 was higher in Leghorns fed the basal or ascorbic acid diets, rather than the beta-glucan or corticosterone diets, whereas the opposite relationship was observed in the Fayoumi line. Expression of IL-4 and IL-18 responded to diet only within the Fayoumi line. The differential splenic expression of birds from diverse genetic lines in response to nutritional immunomodulation emphasizes the need for further study of this process.

Effect of dietary ascorbic acid supplementation level on productivity, mortality, and carcass characteristics of Venda chickens

Two experiments were carried out to determine the effect of dietary ascorbic acid supplementation levels on productivity, carcass characteristics, and mortality of indigenous Venda chickens. The first experiment determined the effect of dietary ascorbic acid supplementation levels on productivity and mortality rate of 175 unsexed Venda chickens between 1 and 6 weeks old. The second experiment determined the effect of dietary ascorbic acid supplementation levels on productivity, carcass characteristics, and mortality rate of 140 female Venda chickens between 8 and 13 weeks old. A completely randomized design was used in both experiments. Supplementation of grower diets with ascorbic acid ranged from 0 to 2,000 mg per kg DM feed in both experiments. Levels of ascorbic acid supplementation for optimum feed intake, feed conversion ratio, growth rate, live weight, and breast meat yield were determined using a quadratic equation. The optimal dietary ascorbic acid supplementation levels for feed conversion ratio, growth rate, and live weight of Venda chickens during the starter phase were 1,050, 1,301, and 1,500 mg/kg DM feed, while, at the grower phase, the optimal supplementation levels for feed conversion ratio, growth rate, live weight, and breast meat yield were 1,000, 1,250, 1,482, and 769 mg/kg DM feed, respectively. Results indicate that different levels of ascorbic acid supplementation optimized feed conversion ratio, growth rate, and live weight of Venda chickens at each growth phase. However, levels of ascorbic acid supplementation for optimum feed conversion ratio, growth rate, and live weight were higher than that for breast meat yield. These findings have implications on ration formulation for Venda chickens.

Vitamin C distribution and retention in the mouse brain

Vitamin C (VC) is a crucial antioxidant in the brain. To assess whether different brain regions vary in their sensitivity to oxidative stress induced by VC depletion, we used the gulonolactone oxidase (gulo) knockout mouse. This mouse, like humans, cannot synthesize VC and thus its tissue VC levels can be varied by dietary VC intake. Gulo knockout mice were fed drinking water containing standard (0.33 g/L), low (0.033 g/L) or zero (0 g/L) VC supplementation levels. After 4 weeks, mice were sacrificed and different brain regions removed for assay of VC and malondialdehyde, a marker of lipid peroxidation. Compared to age-matched wild-type controls, the cerebellum, olfactory bulbs and frontal cortex had the highest VC content, whereas the pons and spinal chord had the lowest. However, in mice that did not receive VC, area differences were no longer significant as all values trended towards zero. Malondialdehyde increased in the cortex as VC supplementation was decreased. The same changes were not observed in the cerebellum or pons, suggesting that cortex is more susceptible to oxidative damage from low VC. These results suggest enhanced susceptibility of the cortex to oxidative stress induced by low VC compared to other brain regions.

Oxidative Stress in Rat Testis and Epididymis Under Intermittent Hypobaric Hypoxia: Protective Role of Ascorbate Supplementation

Hypobaric hypoxia (HH), an environmental condition of high altitude encountered by mountaineers, miners, and observatory, rural health, border patrol, and rural education workers, jeopardizes normal physiologic functions in humans. The present study was conducted to evaluate the effects of intermittent HH (IHH; equivalent to 4600 m above mean sea level) on oxidative stress and the protective role of dietary ascorbic acid on rat testis and epididymis. Ten-week-old male Wistar rats were assigned to 1 of 6 groups: 1) normobaric (Nx), 2) Nx + physiologic solution (Nx + PS), 3) Nx + ascorbic acid (Nx + AA), 4) IHH, 5) IHH + PS, or 6) IHH + AA. Animals subjected to IHH were exposed for 96 hours followed by normobaric conditions for 96 hours for a total of 32 days. The control groups (2 and 5) were injected with doses of PS, and the treated groups (3 and 6) were injected with doses of AA (10 mg x kg(-1) body weight) at an interval of 96 hours. Rats were sacrificed on day 32 after initiation of the protocol. The testis and epididymis were collected to determine the activity and expression of glutathione reductase and the levels of lipid peroxide formation. An epididymal sperm count was also performed in each animal. The results of this study revealed that IHH induced lipid peroxidation, a reduction in glutathione reductase activity in testis and epididymis, and a significant decrease in epididymal sperm count. Treatment with AA prevented these changes. In conclusion, AA was capable of decreasing oxidative stress in testis and epididymis under IHH. This protection by AA of the IHH-induced lipid peroxidation can be explained in part by the preservation of glutathione reductase activity in these organs.

Effect of Dietary Ascorbic Acid Supplementation on Gonadal Maturation in Japanese Parrot Fish

Effect of Dietary Ascorbic Acid Supplementation on Gonadal Maturation in Japanese Parrot Fish

Effect of Dietary Ascorbic Acid on Performance of Broiler Chickens Exposed to Different Lighting Regime

A 2 x 2 factorial experiment was conducted to determine the performance of 400 Anak broiler chicks exposed to two lighting regimes viz. 12 h light:12 h darkness and 24 h light:0 h darkness and fed diets containing two levels of ascorbic acid (0 and 250 mg AA/kg of feed). Each treatment was replicated four times with 25 birds per replicate. Results showed that at the starter phase of growth, chicks on continuous lighting regime recorded significantly (p 0.05) effect on weight gain but addition of ascorbic acid in the diet significantly (p 0.05) between continuous and limited lighting on feed: gain ratio. However, chicks with ascorbic in their diet recorded significantly (p<0.05) better feed: gain ratio than those without ascorbic acid. Inclusion of ascorbic acid in the diet significantly (p<0.05) reduced feed cost per kilogram weight gain. Ascorbic acid inclusion significantly (p<0.05) increased femur weight but not femur ash and tibia length. Continuous lighting and inclusion of ascorbic acid from diets increased incidence of leg abnormality significantly. Inclusion of ascorbic acid significantly (p<0.05) reduced the severity of leg abnormality. In conclusion continuous lighting and ascorbic acid in the diet may improve weight gain, feed: gain ratio, reduced feed cost per kilogram weight gain and reduction in the severity of leg abnormality. It may be recommended that under continuous lighting, inclusion of ascorbic acid in the diet may be recommended for balanced growth of the chicks.

The effects of dietary ascorbic acid supplementation on collagen and amino acid concentrations in Japanese quails exposed to heat stress

A considerable body of data exists regarding the role of vitamin C in mammalian physiology; however, there are no data about the effects of dietary ascorbic acid supplementation on collagen concentrations and amino acid levels in animals exposed to heat stress. The present study investigated the effects of supplementary ascorbic acid intake on collagen concentrations in the brain and heart tissue in Japanese quails. In addition, glycine, glutamine, histidine, asparagine, and serine contents in the livers of the same animals were measured. Japanese quails were allocated into 4 groups, each of which was exposed to heat stress (34.8 ± 1.25 °C) for 75 days. Control animals were fed a basal diet, while animals in the experimental groups were fed a basal diet supplemented with 150, 250, or 500 mg of L-ascorbic acid kg^{-1} of diet. Compared to the control group, mean collagen concentration in brain tissue significantly (P < 0.05) increased only in Japanese quails given 250 mg of L-ascorbic kg^{-1} of diet. On the other hand, heart tissue collagen content in the quails fed vitamin C did not significantly increase; in fact, the collagen content in the group fed 500 mg of L-ascorbic acid kg^{-1} of diet significantly decreased (P < 0.01). Amino acid content in the liver significantly increased in the group fed 150 mg of L-ascorbic acid kg^{-1} of diet (P < 0.01 for serine and P < 0.001 for the others). In conclusion, vitamin C had profound effects on collagen synthesis and amino acid metabolism in Japanese quails subjected to heat stress. Results of the present study also indicate that addition of high-dose dietary vitamin C-higher than 250 mg kg^{-1} of diet-may have detrimental effects in quails exposed to heat stress.

Infantile Scurvy: Two Case Reports

Background. Ascorbic acid (vitamin C) is necessary for the formation of collagen, reducing free radicals, and aiding in iron absorption. SCURVY, a disease of dietary ascorbic acid deficiency, is uncommon today. It still exists in high risk groups including economically disadvantaged populations with poor nutrition. The incidence of SCURVY in the pediatric population is very low. Cases Report. Here we report two cases of SCURVY revealed by subperiosteal hematoma in children with cerebral palsy and developmental delay. Conclusion. SCURVY is extremely rare in children. Musculoskeletal manifestations are prominent in pediatric SCURVY. Multiple subperiosteal hematomas are an important indicator for diagnosis.

Ascorbic acid influences the development and immunocompetence of larval Heliothis virescens

AbstractAscorbic acid, known to be a free radical scavenger and vital to insect development, is important in larval resistance to baculovirus infection. We sequentially elevated the ascorbic acid content in an ascorbic acid‐depleted diet and evaluated the effect on larval Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) development and immunocompetence. Dietary ascorbic acid levels lower than 0.7 g l−1 slowed the growth rate of larvae, reduced pupal weights significantly, and severely inhibited adult emergence. Larvae developing on ascorbic acid‐free diet experienced far higher levels of mortality following per os infection with virus. Additionally, viral infection in larvae fed an ascorbic acid‐free diet, as monitored by epifluorescence microscopy, showed signs of infection much earlier than larvae fed control levels of ascorbic acid. These results demonstrate an indirect correlation between the level of ascorbic acid in the food stream of larval H. virescens and the susceptibility of the insect to baculoviral infection.