scholarly journals Anxiolysis and recognition memory enhancement with long-term supplemental ascorbic acid (vitamin C) in normal rats: possible dose dependency and sex differences

2015 ◽  
Vol 2 (1) ◽  
pp. 4
Author(s):  
Robert N Hughes ◽  
Nicola J Hancock ◽  
Rikki M Thompson
1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.


2019 ◽  
Vol 104 (7) ◽  
pp. e2.58-e2
Author(s):  
Amy-Jo Hooley ◽  
Brandy Cox ◽  
David Devadason ◽  
James Hunter

AimTo assess if routine monitoring of vitamin C in long term parenteral nutrition (PN) patients should be routinely carried out, following a case report of a child with clinical vitamin C deficiency.MethodsVitamin C is an essential water soluble nutrient that cannot be synthesised or stored by humans.1 It is a potent antioxidant with anti-inflammatory and immune- supportive roles,1 Vitamin C levels are depleted in critically ill patients, those with restricted diets, smokers, and those with severe digestive disorders. The stability of micronutrients in PN bags is assumed but rarely confirmed, although a decrease in vitamin C content has been observed when there is a long delay between preparation and packaging.2 The patient, a five year old child stable on long term established full PN presented with a one month gradual reduction in mobility, refusal to weight bear, intermittent temperatures, raised CRP and asymptomatic hypercalcaemia on routine bloods. Investigations included bone profile, vitamin D, and parathyroid hormone levels, and routine sepsis screening. Following the extensive work up for systemic disorders and multiple conversations with orthopaedic and radiology specialists, it was discovered that the patient had bilateral metaphyseal irregularities, which were felt to be in keeping with recognised radiological appearances seen in severe vitamin C deficiency. As a result of this her PN bags were made manufactured and analysed in house quality control laboratory using a method involving UV –vis spectrophotometer to analyse the rate of oxidative decomposition of vitamin C within the bags.ResultsIn the United Kingdom children on long term PN programmes are routinely monitored for selected micronutrient deficiency, but not routinely vitamin C. The vitamin C was increased in the PN to three times the baseline dose for this patient, and a dramatic improvement in the patients symptoms were observed within 5 days, and radiological improvement was noted within 6 weeks after commencing treatment. Unfortunately baseline vitamin C levels were not obtained prior to starting treatment, but levels one month later still showed a significant clinical deficiency. The test bags that were analysed within the laboratory showed that on manufacture the bags contained 48.34 mg/L of ascorbic acid, but by 48 hours this had decreased to 8.5 mg/L.ConclusionVitamin C in PN is at significant risk of degradation by oxidation. Awareness of signs and symptoms of micronutrient deficiency and vigilance of micronutrient deficiencies not routinely measured in children on parenteral nutrition is important. Also more research is required into the oxidation rate of vitamin C in PN to establish how much is required within the PN bag to ensure the recommended daily intake in a PN dependent patient.ReferencesCarr AC, Rosengrave PC, Bayer S, Chambers S, Mehrtens J, Shaw GM. Hypovitaminosis C and vitamin C deficiency in critically ill patients despite recommended enteral and parenteral intakes. Crit Care. 2017;21(1):300. Published 2017 December 11. doi:10.1186/s13054-017-1891-yConroy S, Alsenani A, Sammons H. Factors influencing reported rate of paediatric medication errors. Archives of Disease in Childhood 2014;99:e3. https://adc.bmj.com/content/99/8/e3.19


2021 ◽  
Vol 6 (1) ◽  
pp. 16
Author(s):  
Bergoi Ibarlucea ◽  
Arnau Perez Roig ◽  
Dmitry Belyaev ◽  
Larysa Baraban ◽  
Gianaurelio Cuniberti

Heat-exposed work activities or prolonged sport sessions suppose a continuous nutrient loss through sweating, leading to long-term health issues. Among prevention steps, the use of miniaturized sensors for real-time monitoring of micronutrient presence directly in sweat can be of great interest. Here, we propose a flexible sensor for the detection of vitamin C (ascorbic acid) based on a very simple process of electrode modification via electrodeposition of a membrane containing CuO nanoparticles. The reductive effect of ascorbic acid on the nanoparticles produces a shift of the redox peaks in cyclic voltammetry analysis, which can be measured at nearly zero volts as a current increase by amperometry. The detection is performed efficiently at the micromolar ascorbic acid levels found naturally in sweat and works at ultra-low potential (−5 mV), showing no interferences with other typical molecules found in the samples. In combination with sensors for other nutrients, this can be a promising approach for preventive healthcare applications.


2009 ◽  
Vol 52 (3) ◽  
pp. 593-600 ◽  
Author(s):  
Martín Roberto Alvarez ◽  
Fernando Osvaldo Kravetz

The aim of this work was to study the short and long term influences of ascorbic acid on Hydrochoerus hydrochaeris, if supplemented in their food. No differences regarding food intake were observed in the absence of vitamin C. On a daily basis, animals accustomed to food containing ascorbic acid prefered to continue eating the same food. Food preference in capybaras did not seem to depend on ascorbic acid availability; however, when accustomed to vitamin C, capybaras might recognize and select ascorbic acid in subsequent food. Mechanisms allowing capybaras to "evaluate" the nutritional quality of their food are discussed, as well as the adaptive value of this behavior in free ranging populations.


1990 ◽  
Vol 33 (1) ◽  
pp. 125-130 ◽  
Author(s):  
M. J. H. Keijbets ◽  
G. Ebbenhorst-Seller
Keyword(s):  

1983 ◽  
Vol 2 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Emil Ginter ◽  
Viera Chorváthová

Several points of contact exist between the metabolism of glucose and vitamin C, which are two substances with a similar molecular structure. A deficiency of vitamin C provokes disorders in glycoregulation reminiscent of diabetes mellitus, and vice versa, diabetes brings about disorders in ascorbic acid metabolism, which may lead to a local vitamin C deficiency in some tissues. This vicious circle can be cut by an increased supply of ascorbic acid. Long-term administration of ascorbic acid depresses cholesterol level in blood serum in the majority of hypercholesterolemic diabetics. Prevention of chronic overt vitamin C deficiency in diabetics may play a positive role in the prevention of diabetic microangiopathies and atherosclerosis.


2002 ◽  
Vol 88 (3) ◽  
pp. 265-271 ◽  
Author(s):  
K. L. M. White ◽  
D. M. Chalmers ◽  
I. G. Martin ◽  
S. M. Everett ◽  
P. M. Neville ◽  
...  

Free radicals and reactive species producedin vivocan trigger cell damage and DNA modifications resulting in carcinogenesis. Dietary antioxidants trap these species limiting their damage. The present study evaluated the role of vitamins C and E in the prevention of potentially premalignant modifications to DNA in the human stomach by supplementing patients who, because of hypochlorhydria and possible depletion of gastric antioxidants, could be at increased risk of gastric cancer. Patients undergoing surveillance for Barrett's oesophagus (n100), on long-term proton pump inhibitors were randomized into two groups: vitamin C (500 mg twice/d) and vitamin E (100 mg twice/d) for 12 weeks (the supplemented group) or placebo. Those attending for subsequent endoscopy had gastric juice, plasma and mucosal measurements of vitamin levels and markers of DNA damage. Seventy-two patients completed the study. Plasma ascorbic acid, total vitamin C and vitamin E were elevated in the supplemented group consistent with compliance. Gastric juice ascorbic acid and total vitamin C levels were raised significantly in the supplemented group (P=0·01) but supplementation had no effect on the mucosal level of this vitamin. However, gastric juice ascorbic acid and total vitamin C were within normal ranges in the unsupplemented group. Mucosal malondialdehyde, chemiluminescence and DNA damage levels in the comet assay were unaffected by vitamin supplementation. In conclusion, supplementation does not affect DNA damage in this group of patients. This is probably because long-term inhibition of the gastric proton pump alone does not affect gastric juice ascorbate and therefore does not increase the theoretical risk of gastric cancer because of antioxidant depletion.


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