Plasma Ascorbic Acid Values Research Articles

A Study of Plasma Ascorbic Acid Values with Relation to the Type of Diet Used in Puerto Rico by Groups of Individuals of Widely Varied Economic Status

A Study of Plasma Ascorbic Acid Values with Relation to the Type of Diet Used in Puerto Rico by Groups of Individuals of Widely Varied Economic Status

Ascorbic acid deficiency in porphyria cutanea tarda

Porphyria cutanea tarda (PCT), the most common form of porphyria, is manifested as skin photosensitivity caused by excess hepatic production of uroporphyrin and heptacarboxylporphyrin. In experimental animal models, ascorbic acid modulates chemically induced uroporphyrin accumulation. The purpose of this study was to determine whether ascorbic acid is decreased in the plasma of patients with PCT. Plasma was obtained after an overnight fast from 21 PCT patients, 16 of whom were infected with hepatitis C virus (HCV), and from a separate group of 9 patients with HCV infection but not PCT. Thirteen PCT patients were studied when they had active disease and 8 after treatment-induced remission. Plasma ascorbic acid was low (<23 μmmol/L) in 11 (85%) of the 13 untreated PCT patients and deficient (<11 μmol/L) in 8 (62%). Two patients with normal ascorbic acid levels (45 and 62 μmol/L) had consumed multivitamins. In 2 patients with deficient ascorbic acid, plasma levels returned to normal after phlebotomy treatment. Of the 8 patients studied during remission, 4 had normal ascorbic acid values and 4 were deficient (5 to 8 μmol/L). Plasma ascorbic acid values were normal for all patients who had HCV but no PCT. These data suggest that plasma ascorbic acid concentrations are commonly low in PCT, but this decrease is unrelated to HCV infection. Ascorbic acid deficiency may be one of the factors that contributes to the pathogenesis of PCT.

Ascorbate and urate are the strongest determinants of plasma antioxidative capacity and serum lipid resistance to oxidation in Finnish men

Copper-induced plasma lipoprotein oxidation resistance has usually been determined in separated low density lipoprotein (LDL) fractions, that do not contain water-soluble antioxidants present in blood plasma. The aim of this study was to find the main determinants of the measurements of copper-induced lipid oxidation resistance (lag time) in whole serum and plasma total peroxyl radical trapping capacity (TRAP) in a population sample of smoking ( n=25) or non-smoking ( n=26) middle aged men at high risk of cardiovascular diseases. Smokers had significantly lower plasma ascorbic acid values, but only slightly lower α-tocopherol, β-carotene and serum urate values than non-smokers. Plasma ascorbic acid concentration explained 23.5% of the lag time variation (standardized regression coefficient β=0.48; P=0.004) in smokers and 5.6% in non-smokers. Serum urate concentration was the strongest determinant of lag time in non-smokers ( β=0.64, P<0.001). In addition, serum albumin, lipid standardized α-tocopherol and serum high density lipoprotein (HDL) cholesterol entered the multivariate regression model for lag time. For plasma TRAP, only urate and ascorbic acid entered the multivariate regression model. Lag times in serum and in isolated very low density lipoprotein (VLDL) and LDL fraction did not correlate, but the maximal rate of these reactions correlated significantly. These results confirm that lipid peroxidation resistance in serum or plasma are associated with ascorbic acid, urate, α-tocopherol, albumin and HDL concentrations. The measurement of lipid oxidation resistance in whole serum might be more physiological than in isolated lipoprotein fraction, as the effects of water-soluble antioxidants are not artificially removed.

Vitamin C intake and plasma ascorbic acid concentration in adolescents.

The relationship between vitamin C intake and status was investigated in a group of adolescents (13-14 years old). Dietary intakes were assessed using a 7 d weighted dietary record method, coupled with the collection of duplicate diets. Vitamin C intakes calculated using food composition tables were compared with values obtained by direct analysis of duplicate diets. Vitamin C status was judged via measurement of plasma ascorbic acid (AA) concentration in blood samples taken after a 12-15 h fast. The relationship between calculated and analysed vitamin C intake and plasma AA concentration was examined. Average daily calculated vitamin C intakes, for the group (n 54) as a whole over a 7 d period, gave a good estimate of intake, as judged by prompt analysis of duplicate diets. However, analysed v. calculated intakes were significantly different for approximately one-third of subjects when data were examined on an individual basis. Large discrepancies between analysed and calculated values could not be accounted for on a food group basis. In all but two individuals, calculated vitamin C intake was in excess of the new reference nutrient intake (RNI, part of the new daily reference values (Department of Health and Social Security, 1991)) of 40 mg and all plasma AA concentrations were well above those used to indicate even a moderate risk of deficiency. A relationship between vitamin C intake and plasma AA was observed for both males (n 19) and females (n 35). However, the relationship was much stronger for males who showed a wider range of both intake and plasma AA values.

Biochemical indices of human vitamin C status

Biochemical indicators of ascorbic acid (AA) status were studied in eleven young adult males fed the same AA deficient diet for 14 wk in a live-in metabolic unit. Supplements of AA were added to the diet to give AA-intake periods of 65 mg/d (2 wk), 5 mg/d (4 wk), 605 mg/d (3 wk), 5 mg/d (4 wk), 605 mg/d (4 d), and 65 mg/d (3 d). Blood plasma, erythrocyte, and leukocyte AA levels all reflected AA intake, however, plasma AA showed less variability than red cell AA levels and was considerably easier to determine than leukocyte AA. Plasma AA values less than 0.40 mg/dL (23 mumol/L) reflected marginal AA status. The daily AA intake calculated to maintain plasma AA levels of at least 0.4 mg/dL (23 mumol/L) in healthy young men was 41 mg. The average AA intake estimated to maximize the total body pool was 138 mg/d. Urine and salivary AA levels were not useful indicators of AA status because urinary AA levels did not discriminate well between adequate and deficient AA intakes and salivary AA levels did not consistently reflect AA intake.

Nutritional status of Mexican American preschool children in a border town

One hundred seventy preschool children of Mexican descent were evaluated for nutritional status. Results from physical measurements, dietary, biochemical, dental evaluations and medical histories are reported. One-thirdof the children had heights one or more standard deviations below the mean of Iowa Growth Standards while one-fourth of the children had weights below the 16th percentile. Twelve percent of the children did not meet two-thirds of the 1968 Recommended Dietary Allowances (RDA) for energy; all children ingested more than two-thirds of 1968 RDA for protein. Protein supplied 11-12%, fat 35-40%, and carbohydrate 46-54% of the energy. Eleven percent of the children did not meet two-thirds of the RDA for calcium; 44% for iron; 13% for thiamin; none for riboflavin; 23% for preformed niacin; 7% for vitamin A; and 29% for ascorbic acid. None of the subjects had low plasma total protein or albumin values. Slightly more than half of the children exhibited iron deficiency based on determinations of serum iron and iron-binding capacity. Less than 1% had low plasma vitamin A levels while 9% had plasmaascorbic acid values of < 0.3 mg/ 100 ml. Essentially all children had adequate levels of thiamin, riboflavin, and iodine in urine. Some 90% of the children over 3 years of age were in need of dental care. A high percentage of children had not been immunized while the rate of childhoon diseases was higher among the study populationthan is found in the United States as a whole. Am. J. Clin. Nut,'. 27: 1359-1368, 1974.

Relationship Between Leucocyte and Plasma Ascorbic Acid Concentrations

Leucocyte and plasma ascorbic acid values were measured in healthy students, adult factory employees, and old people not receiving supplementary vitamin C and in healthy old people receiving 500 mg of vitamin C daily. Significant positive correlations between leucocyte and plasma ascorbic acid were found in all the groups. The regression lines differed significantly between one another within the sexes, but the pooled lines for each sex did not differ significantly in the unsupplemented groups. The relationship between plasma and leucocyte ascorbic acid values in the supplemented group differed significantly from that in the pooled unsupplemented groups.There was a limited range of variation in leucocyte ascorbic acid values compared with the range in plasma values in the supplemented group, whereas there was a wider range of variation in the leucocyte values in the unsupplemented groups. Leucocytes can therefore achieve a saturation level of ascorbic acid. Measurement of leucocyte ascorbic acid concentrations alone does not provide a reliable guide for the estimation of tissue status of ascorbic acid in normal individuals. Leucocyte concentrations provide a measure of the availability of ascorbic acid for storage, and plasma levels give an indication of its metabolic turnover rate. When these values are related the regression lines provide information about the storage and metabolism of ascorbic acid in normal individuals.

Influence of Controlled Temperatures on Growth Rate and Plasma Ascorbic Acid Values in Swine

Two factorially designed experiments were conducted in the psychrometric chambers of Herrick Laboratory to study the effect of temperature, as a stressor, on the rate of gain and on plasma ascorbic acid levels of growing pigs. Chamber regimens consisted of 29.4° and 85% relative humidity, 18.3° and 85% relative humidity and rotation of animals between these 2 temperatures every 3 days. Thirty-six Poland China and 36 Hampshire swine, replicated in time, were studied. The pigs were fed a balanced 16% crude protein corn-soybean meal ration and water was available. Statistical analysis of the plasma ascorbic acid values indicated a significant (P < 0.01) quadratic response to the week on test. There was also a significant (P < 0.05) decrease in weekly plasma ascorbic acid due to the higher temperature, but the quadratic response was not altered. When the weekly average daily gains of the pigs were plotted against the weeks on test a cyclic pattern was observed similar to that of the weekly plasma ascorbic acid values. When the plasma ascorbic acid values were highest, weight gains were lowest; when ascorbic acid levels were lowest, weight gains were highest.

Certain Trace Elements in the Feeds, Organs, and Tissues of a Selected Group of Repeat Breeding Cows in Northeastern Wisconsin

Summary In an effort to determine the relationship of trace minerals to the repeat breeding cow problem, a study of the distribution of manganese and cobalt in the feeds fed the cows from problem herds and the distribution of cobalt and manganese in certain tissues and organs of problem cows has been made. It is evident that no single cause was responsible for the repeat breeder cow from these herds. Low blood plasma ascorbic acid values were found to exist. There was definite evidence of low or marginal cobalt intake associated with many of these problem herds. The manganese concentrations of the feeds from these farms was on the low side of the normal range, while ovarian concentrations were definitely low. It appears from these data that trace minerals have little if any direct relationship to the repeat breeding cow problem, although this possibility is not precluded by the data.

Studies on Ketosis in Dairy Cattle. XI. Lipids, Minerals and Ascorbic Acid in the Blood of Cows with Spontaneous Ketosis

Summary In a study with 18 cows diagnosed as having ketosis, an analysis was made of various blood and blood plasma substances. Plasma phospholipids and cholesterol ester fractions were somewhat low, particularly in the later stages of ketosis. Free cholesterol in the plasma was relatively normal. The amount of free ether-petroleum ether soluble non-volatile acids in plasma determined by acidometric titration was relatively high in the later stages of ketosis. The neutral fat fraction was relatively low in the early stages of ketosis and normal or high in the later stages. Marked variations were observed in the plasma ascorbic acid values. The serum phosphatase activity was relatively low. The plasma acid-soluble phosphorus values, both inorganic and organic, were sometimes low but were normal in most cases. Plasma sodium and potassium were normal and the blood chloride values also were in the normal range. Additional data on the effect of fasting and other factors secondary to ketosis are needed before the data can be properly evaluated.

Utilization and Excretion of Ingested Ascorbic Acid by the Dairy Cow

Summary A Holstein cow was maintained in normal physical condition for a period of 15 months on a ration containing very little ascorbic acid. During this period a normal male calf was born. Blood plasma ascorbic acid values ranged from 0.28 to 0.59mg. per 100ml. but usually fluctuated between 0.30 and 0. 45mg. per 100ml. As the lactation period progressed the total daily ascorbic acid excretion in the milk diminished in a manner paralleling the decrease in milk volume. During this time the urinary ascorbic acid excretion appeared to be erratic with values ranging from 14.1 to 97.8mg. per 24 hours. The ingestion of large amounts of ascorbic acid increased the urinary excretion of the vitamin very slightly and then only temporarily. The rate of urinary excretion of the vitamin appeared to be greater during the daytime than during the night. In vivo and in vitro rumen studies, made possible with the aid of a rumen fistula, showed that crystalline ascorbic acid in amounts of 150g. was rapidly destroyed in the rumen. Ascorbic acid supplied in a natural form as Cerograss Chops, was also destroyed in the rumen but at a slower rate owing, presumably, to the slower dissolution of ascorbic acid from the natural grasses. These studies also indicated that the destruction of ascorbic acid in the rumen was a result, at least in part, of the action of microorganisms. The results of these experiments may be summarized, in support of the probable synthesis of ascorbic acid by the dairy cow, as follows: 1) ascorbic acid either in the crystalline form or as a part of a natural product ( Cerograss Chops ) is destroyed rapidly in the rumen; 2) the apparent independence of the cow for dietary ascorbic acid is reflected by normal concentrations of ascorbic acid in the blood and milk in spite of a low ascorbic acid intake over a prolonged period of time; and finally, 3) the ingested intake of ascorbic acid on this lowascorbic acid ration is exceeded by the combined output of the vitamin in the milk and the urine.

The Relationship between a Low Carotene Intake and Urinary Excretion of Ascorbic Acid in Dairy Cattle

Summary Ascorbic acid excretion in normally fed heifers varied from 25.8 to 110.5 mg. per day. When fed 5 grams of chlorobutanol for 10 days normally fed heifers excreted 210 to 399 mg. of ascorbic acid per day. Ascorbic acid excretion of pregnant heifers receiving a ration low in carotene was from 4 to 6 times greater than in similar animals normally fed. The feeding of 5 grams of chlorobutanol for 10 days to pregnant heifers receiving a ration low in carotene stimulated the excretion of ascorbic acid very little. The chlorobutanol caused an increase in plasma ascorbic acid values of the normally fed pregnant heifers but not in similar heifers receiving a low carotene ration. Dairy males excreted varying amounts of ascorbic acid regardless of the level of carotene intake, except when made severely deficient, in which case there was a decrease in ascorbic acid excretion. Normally fed males excreted considerably more ascorbic acid per kilo of body weight than normally fed females. It still remains to be shown that a low carotene intake under practical farm conditions has a depressing effect on ascorbic acid synthesis to the extent of altering breeding efficiency.

Effect of Ascorbic Acid Injections on the Amount in the Blood Plasma of Laying Hens

EARLIER papers of this series have been concerned with the ascorbic acid content of the blood plasma of chickens and laying hens fed typical poultry rations. Holmes, Tripp, and Satterfield (1938), reported that the ascorbic acid content of plasma of rapidly growing eight-week old Rhode Island Red chicks varied from 1.56 mg. to 2.23 mg., and averaged 2.04 mg. percent, whereas that of 12-week old chicks varied from 1.46 mg. to 2.43 mg., and averaged 2.05 mg. percent. They found no consistent relationship between the plasma ascorbic acid values of the different sexes. Later these authors (1939) studied the ascorbic acid content of the blood plasma of Rhode Island Red pullets which received a typical poultry ration during a 15-month laying period. The ascorbic acid content of the blood plasma of the pullets at the various stages of the experiment was 1.84 mg. percent at the beginning of the laying .

A Study of Plasma Ascorbic Acid Values with Relation to the Type of Diet Used in Puerto Rico by Groups of Individuals of Widely Varied Economic Status

Plasma ascorbic acid determinations have been made for a total of 366 subjects, all citizens or long-time residents of Puerto Rico. These subjects were selected on the basis of seven groups of not less than fifty individuals each according to the income categories: (1) satisfactory income and (2) low income or no income. Information on food eaten the day preceding the examination and on dietary habits, in general, was also obtained. The data from each of the seven groups were summarized on the basis of ranges for plasma ascorbic acid values usually accepted as indicating (1) severe deficiency of vitamin C, (2) near deficiency, (3) satisfactory nutrition, and (4) good nutrition. Of the 366 subjects examined, 212 or 57.9%, had plasma ascorbic acid concentration values in the severe deficiency range. The high percentage of values in this range from one of the satisfactory income groups is emphasized as indicating that low income is not the only cause of vitamin C undernutrition. The information on dietary habits reveals a close correlation between plasma ascorbic acid concentration and the presence of fruits and other vitamin C-rich foods in the diet. The relation of level of plasma ascorbic acid concentration to deficiency of vitamin C and the requirement of this vitamin is discussed.

Blood Plasma Ascorbic Acid Values Resulting from Normally Encountered Intakes of this Vitamin and Indicated Human Requirements: Two Figures

Blood Plasma Ascorbic Acid Values Resulting from Normally Encountered Intakes of this Vitamin and Indicated Human Requirements: Two Figures