Serum Ascorbic Acid Levels Research Articles

Serum ascorbic acid and other correlates of gallbladder disease among US adults.

This study examined the correlates of clinical gallbladder disease among US adults and whether serum ascorbic acid levels are associated with a decreased prevalence of gallbladder disease. Cross-sectional analyses of data from the Second National Health and Nutrition Examination Survey were conducted. A total of 384 women (8%) and 107 men (3%) reported a history of gallstone disease, and 347 women (7%) and 81 men (2%) reported a history of cholecystectomy. An inverted U-shaped relation was found between serum ascorbic acid level and clinical gallbladder disease among women but not among men. Ascorbic acid, which affects the catabolism of cholesterol to bile acids and, in turn, the development of gallbladder disease in experimental animals, may reduce the risk of clinical gallbladder disease in humans.

Relation of Serum Ascorbic Acid to Serum Lipids and Lipoproteins in US Adults

Objective: To examine the relation of serum ascorbic acid level to serum lipid and lipoprotein levels among a random sample of the US adult population.Methods: Using linear regression, the relation of serum ascorbic acid level to serum lipid and lipoprotein levels was examined among 5,412 women and 5,116 men enrolled in the Second National Health and Nutrition Examination Survey (NHANES II), 1976–1980. Age, race, body mass index, level of physical activity, level of education, alcohol intake, and dietary energy, cholesterol, and fat intakes, and other potential confounders were included in the multivariate models.Results: Serum ascorbic acid level was independently associated with high-density lipoprotein cholesterol (HDL-C) among women; each 1 mg/dl increase in serum ascorbic acid level (range 0.1 to 2.7 mg/dl) was associated with a 2 mg/dl increase in HDL-C level (p=0.001). Because other investigators have demonstrated an inverse relation between ascorbic acid intake or blood levels and total serum cholesterol in individuals with elevated total serum cholesterol levels, we analyzed four subgroups of NHANES II participants with total serum cholesterol levels >200 mg/dl. Among women with total serum cholesterol levels ≥200 mg/dl, each 1 mg/dl increase in serum ascorbic acid level was independently associated with an increase of 2 to 3 mg/dl in HDL-C level (p≤0.05). Serum ascorbic acid level was not significantly associated with other serum lipids or lipoproteins.Conclusions: If the observed associations are linked causally, they would suggest that ascorbic acid is a factor in cholesterol homeostasis among women and may be particularly important for women at increased risk for coronary heart disease.

Serum Ascorbic Acid and Cardiovascular Disease Prevalence in U.S. Adults

To examine the relation between serum ascorbic acid level and the prevalence of cardiovascular disease, we analyzed data from 6,624 U.S. men and women enrolled in the Second National Health and Nutrition Examination Survey. We calculated odds ratios and 95% confidence intervals to estimate the relative prevalence of cardiovascular disease, defined as self-reported coronary heart disease or stroke, or a diagnosis of peripheral vascular disease based on physical examination. Serum ascorbic acid levels were independently associated with prevalence of coronary heart disease and stroke; a 0.5-mg per dl increase in serum ascorbic acid level was associated with an 11% reduction in coronary heart disease and stroke prevalence. We also analyzed the relation of ascorbic acid, grouped into low to marginal, normal, and saturation serum categories, to cardiovascular disease. Compared with participants with low to marginally low serum ascorbic acid levels, we found a 27% decreased prevalence of coronary heart disease (95% confidence interval = 10-41%) and a 26% decreased prevalence of stroke (95% confidence interval = 3-44%) among participants in the highest serum ascorbic acid category. Serum ascorbic acid levels were not consistently associated with prevalence of peripheral vascular disease. These results are consistent with the hypothesis that increased ascorbic acid intake may decrease the risk of coronary heart disease and stroke.

Low levels of serum ascorbic acid in elderly patients with hip fracture

The serum concentration of ascorbic acid was measured in 40 elderly patients with a recent hip fracture and compared to values measured in 102 home-living elderly. The concentrations were 37 +/- 22 mumol l-1 vs 50 +/- 29 mumol l-1 (p < 0.01). Among the patients admitted from home-living conditions and controls, 20 pairs could be matched with respect to age, sex and season for the test. Serum ascorbic acid concentration was significantly lower in the hip fracture patients (34 +/- 19 mumol l-1 vs 54 +/- 30 mumol l-1, p < 0.01). In the matched pairs, a seasonal variation in serum ascorbic acid concentration was found in the controls, but not in the hip fracture patients. As previous studies have found decreased concentrations of several nutritional factors in hip fracture patients, our findings might indicate that a reduced serum concentration of ascorbic acid could be a part of a general nutritional insufficiency in several patients with hip fracture.

Functional assessment of proliferating hepatocytes stimulated by hepatic stimulatory substance in ascorbic acid biosynthetic enzyme-deficient rats.

The functional ability of hepatic stimulatory substance (HSS)-stimulated proliferating hepatocytes was investigated by intrasplenic and/or intraportal transplantation in ascorbic acid (AsA) biosynthetic enzyme-deficient (ODS-od/od) rats that die of osteogenic disorders unless there is AsA supplementation. HSS was extracted from regenerating porcine livers. Hepatocytes isolated from the livers of congeneic ODS-+/+ rats that are capable of synthesizing AsA were transplanted into the spleen (Sp-HTx) and/or the portal vein (Pv-HTx) of ODS-od/od rats. The recipients were divided into eight groups as follows: HSS-untreated groups [group Ia, sham-operated, HTx(-); group IIa, Sp-HTx; group IIIa, Pv-HTx; and group IVa, Sp- and Pv-HTx], HSS-treated groups [group Ib, HSS only; group IIb, Sp-HTx + HSS; group IIIb, Pv-HTx + HSS; and group IVb, Sp- and Pv-HTx + HSS]. The recipients were given a diet and water containing AsA for 6 weeks after HTx, and AsA supplementation was then halted. The average bromodeoxyuridine (BrdU) labeling index (LI) and hepatocyte-occupied ratio in the spleen (H/S ratio) of HSS-treated rats were significantly higher than those of HSS-untreated rats. All the rats in HSS-untreated groups and group Ib died by 8 weeks after the cessation of AsA. In HSS-treated groups IIb, IIIb, and IVb, the survival rates were 60%, 50%, and 80%, respectively, at 16 weeks after HTx. The average serum AsA level of the surviving rats in groups IIb, IIIb, and IVb was significantly higher than that in HSS-untreated groups. These results indicate that HSS treatment induced rapid proliferation of transplanted hepatocytes in the spleen and the portal vein, and that these proliferating hepatocytes synthesized AsA and improved the survival rate of ODS-od/ od rats.

Multilocational hepatocyte transplantation for treatment of congenital ascorbic acid deficiency rats

We attempted multilocational hepatocyte transplantation (HCTx) including hepatocyte-bearing polyurethane foam (PUF) to treat congenitally ascorbic acid (AsA) biosynthetic enzyme-deficient (ODS- od/od) rats. Hepatocytes isolated from the liver of congeneic rats were transplanted into the portal vein (Pv), spleen (Sp), omentum (Om), and mesentery (Ms). Hepatocyte-bearing PUF was transplanted into the Om and Ms. Experimental groups were divided into four groups (group I; Pv + Sp, group II; Pv + Sp + Om + Ms, group III; Pv + Sp + hepatocyte-bearing PUF, group IV; control). The average serum AsA level of the surviving rats in group II and III was significantly higher than that in group I 3 mo after HCTx. Histological examination showed small foci of surviving hepatocytes in the Om and Ms tissues and in the connective tissue in the PUF. ODS- od/od rats survived for a long time by multilocational HCTx.

Serum β–carotene, vitamin E, vitamin C and malondialdehyde levels in several types of cancer

We measured the levels of serum carotenoids (beta-carotene), total tocopherol (vitamin E), ascorbic acid and malondialdehyde (MDA) in newly diagnosed cancer cases. Levels of the antioxidants and MDA in serum samples from 208 subjects with cancer affecting different sites (59 breast, 38 head and neck, 46 genitourinary, 12 lung, 20 gastrointestinal and 33 other sites) were compared with levels in 156 controls. Cases and controls were compared with respect to a number of potentially confounding factors: age, sex, smoking status, Quetelet index (kg/m2), diet and alcohol intake. Mean (+/- SD) levels of beta-carotene, vitamin E and vitamin C were significantly lower among the cases than the controls (49.35 +/- 36.55 micrograms/l, 0.60 +/- 0.14 mg/dl, 0.40 +/- 0.27 mg/dl and 75.31 +/- 28.59 mg/dl, 0.98 +/- 0.13 mg/dl, 0.88 +/- 0.47 mg/dl, respectively) (P < 0.05). On the other hand, mean levels of MDA were significantly higher among the cases than the controls (6.79 +/- 1.22 nmol/ml and 3.52 +/- 0.97 nmol/ml, respectively) (P < 0.05). The results obtained suggest that measurement of serum antioxidants and MDA levels may provide further useful information when evaluating cancer patients.

Importance of supplemental vitamin C in determining serum ascorbic acid in controls from a cervical cancer case‐control study: Implications for epidemiological studies

Classification of individuals by their vitamin C intake was investigated in 493 control subjects from a cervical cancer case-control study. The influence of dietary and supplemental sources of vitamin C, as well as demographic and life-style factors, on serum ascorbic acid were examined. Usual dietary intakes of vitamin C were determined from a food frequency questionnaire and recent intakes from a 24-hour recall taken at the time of blood collection. Vitamin supplement information was obtained at both times. In a regression analysis, the factors found to predict serum ascorbic acid were total recent vitamin C intake, an indicator variable for supplement use, body mass index, number of cigarettes smoked per day, race, education, and age. Higher levels of serum ascorbic acid were found among older nonsmoking highly educated leaner white women. Consideration of supplements, in addition to dietary sources of vitamin C, improved correlation coefficients between serum ascorbic acid and usual vitamin C intake from 0.19 to 0.32 and between serum ascorbic acid and recent intake from 0.36 to 0.56. Furthermore, whereas only a twofold difference between the first and fourth quartiles of serum ascorbic acid was observed using recent dietary vitamin C without supplements, this range increased to sixfold with addition of supplement data. Epidemiological studies should consider use of total vitamin C intakes from supplement and food sources to permit accurate classification of individuals.

Serum levels of ascorbic acid (vitamin C) in patients with Parkinson's disease

To elucidate the possible role of vitamin C in the risk for developing Parkinson's disease (PD), we compared serum levels of ascorbic acid (vitamin C), measured by a fluorometric method, of 63 PD patients using their spouses as the control group. The serum levels of vitamin C did not differ significantly between the groups (47.13 ± 0.89 μg/ml for PD and 47.60 ± 0.60 μg/ml for controls). There was no influence of antiparkinsonian therapy on vitamin C. Serum levels of vitamin C did not correlate with age, age at onset and duration of the disease, scores of the Unified PD Rating Scale or the Hoehn and Yahr staging in the PD group. These results suggest that serum vitamin C concentrations are apparently unrelated to the risk of developing PD.

Scurvy in a nonalcoholic person in the United States

Scurvy is rarely diagnosed in our society today. The authors describe the case of a 31-year-old man with weakness, gingival pain, and a rash over the lower extremities. He had a history of poor nutritional intake, no alcohol consumption, and a 13 pack-year history of cigarette smoking. Laboratory studies revealed an extremely deficient serum ascorbic acid level. Treatment was begun with oral ascorbic acid tablets and, within 3 days after discharge, all clinical symptoms of scurvy had resolved. Scurvy is an easily treated disease and should be considered when there is an appropriate history and classic clinical findings. Because vitamin C deficiency can be seen in many chronic disease states, it is important to recognize some of the early features and clinical manifestations of such nutritional deficiencies.

Effect of ascorbic acid supplementation on the sperm quality of smokers

To determine the effect of ascorbic acid supplementation on the sperm quality of heavy smokers. Microscopic examination of semen for 1 month during supplementation with placebo or ascorbic acid at dose levels of 200 or 1,000 mg/d. Department of Obstetrics and Gynecology, The University of Texas Medical Branch. Seventy-five men (20 to 35 years old) randomly divided into one of three supplementation groups: placebo, 200 mg and 1,000 mg of ascorbic acid. Improvement in sperm quality as compared with presupplementation levels and between the three treatment groups. The placebo group showed no improvement in sperm quality. The groups receiving ascorbic acid showed improvement in sperm quality with most improvement in the 1,000-mg group. Pearson's correlation showed statistically significant relationships between the weekly group means of serum and seminal plasma ascorbic acid levels and sperm qualities. Ascorbic acid supplementation of heavy smokers in excess of 200 mg/d results in improved sperm quality.

Serum ascrobic acid levels in men aged 55–75 years: Association to selected social factors and biochemical parameters

Serum ascorbic acid (SAA) levels were determined in 500 subjects aged 55-75 years participating in the New Risk Factors (NRF) Survey between March and December 1990. In the total sample mean concentration of SAA was 8.75 mg/1 (95% confidence interval: 8.41-9.20). SAA levels of 2 mg/l or less (severe hypovitaminosis C) were found in 19 subjects (3.8%). A further 9.6% of subjects (n=48) has SAA levels between 2 and 4 mg/l (marginal hypovitaminosis C). Subjects with hypovitaminosis C reported a significantly higher daily cigarette consumption and had higher blood lead (B-Pb) and blood cadmium (B-Cd) levels. An Inverse relationship was found between SAA levels and smoking status, body mass index (BMI) and B-Pb. Among current smokers aged 55-65 years the prevalence of hypovitaminosis C was not significantly higher than in non smokers (chi(2) was 2.4 for severe and 4.7 for marginal hypovitaminosis C, respectively). On the contrary, in subjects aged 66-75 years the occurrence of hypovitaminosis C was significantly higher in smokers than in non-smokers (chi(2) was 6.6 for severe and 10.3 for marginal hypovitaminosis C. respectively).

Ascorbic acid requirements for smokers: analysis of a population survey

The recommended dietary allowance (RDA) of ascorbic acid for smokers was recently increased from 60 to 100 mg. To determine whether this new RDA for smokers is sufficient to reduce the risk of low serum ascorbic acid (AA) concentrations (LoC) to the same concentration as nonsmokers, we analyzed the dietary intakes and serum concentrations of AA in 11,582 adult respondents in the National Health and Nutrition Examination Survey (1976-1980). Serum AA concentrations and the risk of LoC (serum ascorbic acid levels less than 23 mumol/L) for smokers consuming different amounts of AA were compared with those for nonsmokers whose AA intake exceeded the RDA (60 mg). Serum AA concentrations were reduced, and risk of LoC increased, in smokers maintaining AA intakes greater than 60, 100, and 150 mg. Only smokers consuming greater than 200 mg AA/d had serum ascorbate concentrations and risk of LoC equivalent to nonsmokers meeting the RDA.

Additional evidence of autoxidation as a possible mechanism of neutrophil locomotory dysfunction in blunt trauma

Previous studies in victims of blunt injury suggest that the observed neutrophil (PMN) locomotory dysfunction is, in part, due to autoxidation. To further clarify the occurrence and significance of autoxidation, we studied changes in levels of glutathione in PMN and of ascorbic acid and alpha-tocopherol in serum and blood cells of postsurgical and blunt trauma patients. Levels of total, reduced, and oxidized glutathione in PMN from trauma patients were similar to normal controls. Serum and cellular ascorbic acid and alpha-tocopherol levels dropped significantly after injury and remained below normal control levels during the 7 to 8-day study period. Low serum alpha-tocopherol was partially explainable on the basis of changes in serum lipids. When serum samples of trauma patients were thawed unprotected without pyrogallol, there was significant loss of recoverable alpha-tocopherol, whereas no significant losses occurred with unprotected thawed normal sera. Less total reducing capacity was observed in PMN of trauma patients compared with normal controls. These findings indicate that synthesis and regeneration capacity of glutathione are intact but that the levels of the consumable antioxidants, ascorbic acid, and alpha-tocopherol are compromised after injury. These results add further support to the hypothesis that autoxidation occurs in trauma.

Antiscorbutic activity of L-ascorbic acid 2-glucoside and its availability as a vitamin c supplement in normal rats and guinea pigs.

Bioavailability of a newly-synthesized and chemically-stable 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) as a vitamin C supplement was investigated in rats and guinea pigs. Oral administration of AA-2G to the animals resulted in an increase of serum ascorbic acid (AA) levels. However, in these sera the intact form was not detectable by the high performance liquid chromatography (HPLC) method, indicating its hydrolysis through the process of absorption. After an intravenous injection of AA-2G, the intact form diminished rapidly from the serum, followed by prolonged and marked elevation of serum AA levels. Various tissue homogenates from rats and guinea pigs were examined for their releasing activity of AA from AA-2G. High activity was observed in kidney, small intestine and serum of rats and in small intestine and kidney of guinea pigs. These hydrolytic activities were completely inhibited by castanospermine, a specific alpha-glucosidase inhibitor, suggesting the participation of alpha-glucosidase in the in vivo hydrolysis of AA-2G. AA-2G was found to exhibit obvious therapeutic effect in scorbutic guinea pigs by its repeated oral administrations. These results indicate that AA-2G is a readily available source of vitamin C activity in vivo.

Ascorbic acid in a New World monkey family: Species difference and influence of stressors on ascorbic acid metabolism

Like other simian primates, the New World monkey Callithrix jacchus, marmoset, and Saguinus fuscicollis, tamarin, require ascorbic acid as an essential nutrient. For adult marmosets, a daily intake of 15 mg/kg metabolic body weight was found to be necessary to obtain a serum level above the kidney threshold. A survey of the serum ascorbic acid level of marmosets and tamarins in a breeding colony resulted in a vast divergence between the two species, indicating a higher ascorbic acid requirement for tamarins. Unaccustomed trial conditions or additional stressors resulted in a higher catabolism of ascorbic acid to CO2 in both species, measured with 14C labeled material, compared to a higher rate of renal excretion when the animals were accustomed to the metabolic cage. These isotope excretion studies suggest a different metabolic behavior of ascorbic acid in the two species. This is supposedly caused by a higher sensitivity of the tamarins when subjected to the same conditions as marmosets.

Blood serum and granulation tissue ascorbic acid and hydroxyproline levels in rats with aseptic and infected wounds

Blood serum and granulation tissue ascorbic acid and hydroxyproline levels in rats with aseptic and infected wounds

Ascorbic acid requirement and assessment of ascorbate status in the common marmoset (Callithrix jacchus).

Marmosets can tolerate an ascorbic acid (AA) deficiency for several weeks without clinical symptoms. After being fed an AA-free diet for 3 months, nonspecific deficiency symptoms became obvious. Different dietary levels of AA resulted in corresponding serum ascorbate levels. The kidney threshold of AA in marmosets is comparable to that in humans. When the minimal AA requirement is defined as the amount that is necessary to maintain a serum AA level above the kidney threshold, then about 20 mg AA/kg body weight is needed. This intake was achieved in our trial with a diet containing 500 ppm AA. Thus, the AA requirement of marmosets is severalfold higher than the AA requirement of humans.

Effect of vitamin C on platelet adhesiveness and platelet aggregation in coronary artery disease patients.

The effect of oral administration of vitamin C on platelet adhesive index (PAI), platelet aggregate ratio (PAg R) and serum ascorbic acid levels was studied. Feeding 75 g of butter to healthy males (group I, n = 10 cases), enhanced the tendency of platelet adhesiveness (PAd) and platelet aggregation (PAg) to a significant level at the end of 4 h. This was distinctly prevented when 1 g of vitamin C was added to the fatty meal. In coronary artery disease (CAD) patients (group II, n = 20 cases) 10 days of vitamin C administration at 1 g every 8 hours decreased the PAd (p less than 0.001) and PAg (p less than 0.05) significantly. There was also a significant (p less than 0.001) rise in the vitamin C levels. The study brings out a property of vitamin C which may be of considerable importance in prevention of chronic thromboatherosclerotic disease of the arteries.

Senile cataract and ascorbic acid loading.

Serum, aqueous humour, and lens ascorbic acid levels were determined by high-performance liquid chromatography in cataract-, closed-angle glaucoma-, and aphakic patients. The total number of 108 patients were subdivided into different groups. In several groups the pre-operative serum and aqueous amounts were tested, whereafter patients in some groups were loaded with ascorbic acid orally. Finally, a second test was performed on samples taken during operation. It turned out that the ascorbic acid concentration mechanism in cataractous eyes needed more than 12 h for maximum reaction on the loading stimulus. The slow reaction is surprising compared to other species, and it may reflect an affection of the secretory process itself in this disease.