Vitamin C in Home Parenteral Nutrition: A Need for Monitoring

To date, there are no recommendations about screening plasma vitamin C concentration and adjust its supplementation in patients on long-term home parenteral nutrition (HPN). The aim of this study was to evaluate vitamin C status and determine if a commercial multivitamin preparation (CMVP) containing 125 mg of vitamin C is sufficient in stable patients on HPN. All clinically stable patients receiving HPN or an intravenous fluid infusion at least two times per week for at least 6 months, hospitalized for nutritional assessment, were retrospectively included, for a total of 186 patients. We found that 29% of the patients had vitamin C insufficiency (i.e., <25 µmol/L). In univariate analysis, C-reactive protein (CRP) (p = 0.002) and intake of only 125 mg of vitamin C (p = 0.001) were negatively associated with vitamin C levels, and duration of follow-up in our referral center (p = 0.009) was positively associated with vitamin C levels. In multivariate analysis, only CRP (p = 0.001) and intake of 125 mg of vitamin C (p < 0.0001) were independently associated with low plasma vitamin C concentration. Patients receiving only CMVP with a low plasma vitamin C level significantly received personal compounded HPN (p = 0.008) and presented an inflammatory syndrome (p = 0.002). Vitamin C insufficiency is frequent in individuals undergoing home parenteral nutrition; therefore, there is a need to monitor plasma vitamin C levels, especially in patients on HPN with an inflammatory syndrome and only on CMVP.

Pharmacokinetic data support 6-hourly dosing of intravenous vitamin C to critically ill patients with septic shock

OBJECTIVES

To study vitamin C pharmacokinetics in septic shock.

DESIGN

Prospective pharmacokinetic study.

SETTING

Two intensive care units.

PARTICIPANTS

Twenty-one patients with septic shock enrolled in a randomised trial of high dose vitamin C therapy in septic shock.

INTERVENTION

Patients received 1.5 g intravenous vitamin C every 6 hours. Plasma samples were obtained before and at 1, 4 and 6 hours after drug administration, and vitamin C concentrations were measured by high performance liquid chromatography.

MAIN OUTCOME MEASURES

Clearance, volume of distribution, and half-life were calculated using noncompartmental analysis. Data are presented as median (interquartile range [IQR]).

RESULTS

Of the 11 participants who had plasma collected before any intravenous vitamin C administration, two (18%) were deficient (concentrations < 11 μmol/L) and three (27%) had hypovitaminosis C (concentrations between 11 and 23 μmol/L), with a median concentration 28 μmol/L (IQR, 11-44 μmol/L). Volume of distribution was 23.3 L (IQR, 21.9-27.8 L), clearance 5.2 L/h (IQR, 3.3-5.4 L/h), and half-life 4.3 h (IQR, 2.6-7.5 h). For the participants who had received at least one dose of intravenous vitamin C before sampling, T0 concentration was 258 μmol/L (IQR, 162- 301 μmol/L). Pharmacokinetic parameters for subsequent doses were a median volume of distribution 39.9 L (IQR, 31.4-44.4 L), clearance 3.6 L/h (IQR, 2.6-6.5 L/h), and half-life 6.9 h (IQR, 5.7-8.5 h).

CONCLUSION

Intravenous vitamin C (1.5 g every 6 hours) corrects vitamin C deficiency and hypovitaminosis C and provides an appropriate dosing schedule to achieve and maintain normal or elevated vitamin C levels in septic shock.

Influence of daily diet on ascorbic acid supply to students

BACKGROUND

Researchers suspect that the accepted adequate ascorbic acid plasma concentration is not being met even after dietary intake of the recommended amount of vitamin C. Current dietary intake recommendation in Poland is 60 mg per day for women and 75 mg per day for man (EAR), while in Western Europe and North America is higher and amounts to 75-90 mg per day.

OBJECTIVE

The paper aimed at studying a correlation between composition of nutrients in daily diet and plasma vitamin C levels in university students. Materials and methods. This study examined diet composition and the nutritional status of ascorbic acid in plasma of 120 university students in Szczecin, Poland. Ascorbic acid was determined in blood plasma using HPLC method. The information concerning diet composition was collected using the method of "7-days food record" prior to blood collection.

RESULTS

Plasma ascorbic acid deficiency (<40 μmol/L) was observed in 23% of women and 28% of men. The average plasma ascorbic acid concentration was 48.65 μmol/L in women and 45.61 μmol/L in men. The average intake of vitamin C in women with observed deficiency was average 46.55 mg/day, whereas in men it was 48.56 mg/day.

CONCLUSIONS

The recommendation of dietary intake of vitamin C in Poland is low in comparison to other countries. Population- based studies are necessary to determine the actual demand for vitamin C in various population groups in Poland. Key words: nutrition, vitamins, dietary intake, diet, ascorbic acid, plasma.

Vitamin C neglect in hemodialysis: sailing between Scylla and Charybdis

In our efforts to meet the vitamin C requirements of dialysis patients we confront a medical dilemma--do we allow the patient to become depleted of vitamin C, with the accompanying hematological and other consequences (Scylla), or do we provide for adequate tissue levels of vitamin C, which has been thought to carry the risk of oxalosis (Charybdis). Many practitioners are certain that either one outcome (deficiency) or the other (oxalic acid toxicity) is inevitable, and much like Odysseus, no safe course is to be found. The recent accumulating evidence that vitamin C improves the management of anemia in dialysis patients compels us to find a safe passage through this dilemma. The serious vitamin C deficiency seen in many patients may also contribute to poor oral health and chronic fatigue. The evidence for oxalosis from vitamin C supplements stems from hemodialysis as practiced 20 years ago. Investigators using this therapy are not observing systemic oxalosis, and the most current data support the conclusion that vitamin C therapy is safe for dialysis patients. The question will be resolved by controlled trials that address both vitamin C effectiveness and safety.

Effects of vitamin C supplementation on the growth ofHeterobranchus longifilisfingerlings

A 12-week growth experiment was conducted to establish the necessity of vitamin C in the nutrition of Heterobranchus longifilis fingerlings. Vitamin C was supplemented at levels of 0 and 50 mg x kg(-1) to a basal diet (42.5% CP), which was fed to triplicate groups of H. longifilis fingerlings. Fish receiving the vitamin C-supplemented diet had significantly improved weight gain (20.7 vs. 16.7 g per fish), feed efficiency ratio (1.03 vs. 1.42), specific growth rate (3.00 vs. 2.74%), protein efficiency ratio (2.26 vs. 1.64), and survival rate (90% vs. 50%). There was a significant decrease in haematocrit and haemoglobin levels in the blood of fish fed no supplemental vitamin C. Furthermore, this group exhibited retarded growth and pathological changes such as vertebral curvature, condensation associated with fragility of the spinal bones. Supplementation of 50 mg vitamin C per kg diet was adequate to prevent the occurrence of vitamin C deficiency in H. longifilis and it was concluded that vitamin C is essential in the nutrition of these fishes.

An epidemic of scurvy in Afghanistan: assessment and response

In March 2002, there were reports of a hemorrhagic fever outbreak in western Afghanistan. It was later confirmed that the hemorrhagic symptoms and increased mortality were actually due to scurvy. Most aid workers did not include scurvy in the initial differential diagnosis because it is uncommon throughout the world and has mainly been reported in refugee populations in recent times. A rapid assessment confirmed the cases clinically, estimated a prevalence rate of 6.3% (a severe public health problem), and determined that the attack rates peaked each year in January and February (the end of the winter). Many Afghans have limited dietary diversity due to isolated locations, lengthy winters, the continuing drought of the last four years, asset depletion, and loss of livelihood. After numerous food and fortification options to prevent future outbreaks had been considered, vitamin C tablet supplementation was selected because of the relatively rapid response time as compared with other prevention methods. A three-month course of vitamin C tablets was distributed to 827 villages in at-risk areas. The tablets were acceptable and compliance was good. No cases of scurvy were reported for the winter of 2002-03. The case study from Afghanistan demonstrates that scurvy can occur in nonrefugee or nondisplaced populations; vitamin C supplementation can be an effective prevention strategy; there is an urgent need to develop field-friendly techniques to diagnose micronutrient-deficiency diseases; food-security tools should be used to assess and predict risks of nutritional deficiencies; and the humanitarian community should address prevention of scurvy in outbreak-prone areas.

Captain Cook's beer: the antiscorbutic use of malt and beer in late 18th century sea voyages

The custom of allowing British seamen the regular use of fermented liquor is an old one. Ale was a standard article of the sea ration as early as the fourteenth century. By the late eighteenth century, beer was considered to be at once a food (a staple beverage and essential part of the sea diet), a luxury (helping to ameliorate the hardship and irregularity of sea life) and a medicine (conducive to health at sea). In particular, beer and its precursors, wort and malt, were administered with the aim of preventing and curing scurvy. This paper examines the use of malt and beer during late eighteenth century British sea voyages, particularly their use as antiscorbutic agents, focusing on James Cook's three voyages during the period 1768-1780. Cook administered sweet wort (an infusion of malt), beer (prepared from an experimental, concentrated malt extract), and spruce beer (prepared mainly from molasses), among many other items, in his attempts to prevent and to cure scurvy. Despite the inconclusive nature of his own experiments, he reported favourably after his second voyage (1772-1775) on the use of wort as an antiscorbutic sea medicine (for which purpose it is now known to be useless). Cook thereby lent credibility to erroneous medical theories about scurvy, helping to perpetuate the use of ineffective treatments and to delay the discovery of a cure for the disorder.

Vitamin C enrichment of fruit juice based ready-to-serve beverages through blending of Indian gooseberry (Emblica officinalis Gaertn.) juice

Physiconutritional qualities of fruits viz. apple, lime, pomegranate, Perlette grape, and Pusa Navrang grape were analyzed and compared with those of Indian gooseberry (Emblica officinalis Gaertn.). Indian gooseberry juice contained the highest vitamin C (478.56 mg/100 ml). Hence, when gooseberry juice was blended with other fruits' juice for the preparation of ready-to-serve (RTS) beverages, it boosted their nutritional quality in terms of vitamin C content. On the basis of overall sensory quality and vitamin C content, RTS beverage prepared by blending gooseberry and Pusa Navrang grape juice in 20:80 ratio was found to be the best.

Pharmacological, morphological and behavioral analysis of motor impairment in experimentally vitamin C deficient guinea pigs

The scurvy shows an inflammatory disease and gingival bleeding. Nevertheless, in an animal model for guinea pigs, described by Den Hartog Jager in 1985, scurvy was associated with a motor neuron disease with demyelinization of the pyramidal tract, provoking neurogenic atrophy of muscles. Aiming at searching the protective role of vitamin C in nervous system, a pharmacological, morphological and behavioral study was conducted. Three experimental groups were used: A100, animals receiving 100 mg/ vitamin C/ day; A5.0, animals receiving 5.0 mg/vitamin C/ day; and A0, animals without vitamin C. We analyzed the weight gain, muscular diameter and behavioral tests. In all tests examined, we found significant differences between the supplemented groups in comparison with scorbutic group (p<0.05). Thereafter, the animals were killed for histopathology of gastrocnemius muscle, spinal cord and tooth tissues. In addition, a morphometric study of periodontal thickness and alpha-motor neuron cell body diameter were done. The vitamin C-diet free regimen seemed to induce a disruption in spinal cord morphology, involving the lower motor neuron, as confirmed by a significant reduction in neuron perycaria diameter and muscular atrophy, complicated by increased nutritional deficit.

A partial supplementation of pasteurized milk with vitamin C, iron and zinc

After supplementation trials, vitamin C, iron and zinc levels were increased by 1789%, 59% and 30%, respectively. Partially supplemented pasteurized milk could be a new alternative with its high nutritive value, good sensory properties and low cost.

Stability of ascorbic acid in commercially available orange juices

OBJECTIVE

To compare the vitamin C content of reconstituted frozen orange juice concentrates at preparation to that of ready-to-drink orange juices purchased 4 to 5 weeks from expiration.

DESIGN

Juices were unsealed and analyzed for reduced and oxidized vitamin C content at the time of purchase and reanalyzed 3 times weekly for 4 to 5 weeks. Same-lot samples of the ready-to-drink juices remained sealed after purchase and were opened for analyses at 3, 2, 1, or 0 weeks before expiration. SAMPLES/SETTING: Orange juices were reconstituted frozen concentrates, ready-to-drink juice packaged in resealable, screw-top containers, or ready-to-drink juice packaged in nonresealable containers. Juices were obtained from local retailers and stored at 4 degrees C in their original containers when appropriate.

STATISTICAL ANALYSES PERFORMED

The reduced vitamin C content of juices analyzed repeatedly, 3 times weekly for 4 weeks, were compared using repeated measures analysis of variance. Linear regression lines were computed for reduced vitamin C in each juice over time, and differences between slopes were analyzed by oneway analysis of variance.

RESULTS

The orange juices from frozen concentrates contained 86 mg reduced vitamin C per fluid cup at initial preparation and 39 to 46 mg/c after 4 weeks of storage. Ready-to-drink juices averaged significantly lower reduced vitamin C: 27 to 65 mg/c at opening and 0 to 25 mg/c at expiration 4 weeks later. Ready-to-drink orange juices had twofold to threefold higher concentrations of oxidized vitamin C vs the orange juices reconstituted from frozen, and the decomposition rate of reduced vitamin C was similar for all juices, about 2% per day once opened.

APPLICATIONS

Ready-to-drink orange juices should be purchased 3 to 4 weeks before expiration date and consumed within 1 week of opening.

Vitamin C function and status in chronic disease

Vitamin C is an essential dietary nutrient required as a co-factor for many enzymes, and humans are among the few animals that lack the ability to synthesize the compound from glucose. The reduced form of the vitamin, ascorbic acid, is an especially effective antioxidant owing to its high electron-donating power and ready conversion back to the active reduced form. Concentrations of the vitamin in body tissues and fluids are regulated through interactions of intestinal absorption, cellular transport, and excretion. The amount of vitamin C needed to prevent scurvy is very small and easily obtained in nearly all Western diets. There is great interest in the clinical roles of vitamin C because of evidence that oxidative damage is a root cause of, or at least associated with, many diseases. Population studies show that individuals with high intakes of vitamin C have lower risk of a number of chronic diseases, including heart disease, cancer, eye diseases, and neurodegenerative conditions. However, these results may simply reflect a more healthful diet or lifestyle for individuals with a high vitamin C intake. At present, data from controlled clinical trials have not established that higher intakes of vitamin C alone will help prevent chronic degenerative diseases. However, the evidence that ascorbic acid acts as an important antioxidant in many body tissues is convincing. The new higher Recommended Dietary Allowance (RDA) for vitamin C of 75 mg for women and 90 mg for men is, for the first time, based on the vitamin's role as an antioxidant as well as protection from deficiency. In healthy people, amounts greater than the RDA do not appear to be helpful. Vitamin C nutriture may be more important for people with certain diseases or conditions. High intakes of the vitamin are generally well tolerated; a Tolerable Upper Level was recently set at 2 g based on gastrointestinal upset that sometimes accompanies excessive intakes.

Risk of inadequate intakes of vitamins A, B1, B6, C, E, folate, iron and calcium in the Spanish population aged 4 to 18

A meta-analysis of the most representative Spanish nutrition studies was carried out to identify inadequate intakes of vitamins, A, B1, B6, C, E, folate, iron, and calcium in children aged 4 to 18. Information on vegetable, fruit and fruit juice/beverage intake was also solicited. Data drawn from the selected studies yielded a total of 6540 children and adolescents in eight geographical areas. The sample was stratified by age (children: 4 to 14 years old and adolescents: 13-18 years old) and sex. Inadequate intakes (below two-thirds of the recommended values) were notable in children for vitamin E, vitamin C, and vitamin A and in girls, iron. In adolescents, low intakes were especially marked for vitamin E and vitamin A, and in girls, calcium, folate, and iron. Adolescents consumed more vegetables, fruit juice, and fruit drinks whereas children had higher fruit intakes. Regional differences in consumption were also detected. Strategies for improving nutrient intake in these vulnerable populations are discussed.

[Vitamin C status of inhabitants of the Gomel region]

The carried out research of vitamin C status of 250 young people 17-20 years old constantly living in region of the periodic radioactive control of the Gomel region of Republic Byelorussia have shown, that in the spring the vitamin C deficiency is observed at more than 55% examined, and autumn this parameter is reduced approximately on 20%. The vitamin C provision of the women is slightly higher, than one of men. The vitaminization of the population within 1 month by polyvitaminic complexes results in twofold reduction of number examined with vitamin deficiency.

[Provision of residents of the city of Kiev with vitamins C and B1. Effectiveness of a complex vitamin-mineral preparation in preventing spring vitamin deficiencies]

The investigation was conducted on provision with vitamins C and B1 of Kyiv inhabitants limited contingent at spring period and efficiency of complex vitamin-mineral preparations in normalisation of the vitamins level in blood of human-subjects. The deficit of vitamin C in 54% and vitamin B1 in 18.5% of the investigated people was revealed. Supradin gave the best results among rest preparations ("Centrum", "Vitrum", "Duovit", "Multi-Tabs") in the normalization of the level of vitamin C and biologically-active form of thiamine (thiamindiphosphate) in the blood of investigated people.

[Effects of biologically active food additives with different contents of vitamins on the vitamin status in humans]

The comparative study of influence of two biologically active food additives with the different contents of vitamins is carried out: a drink "Zolotoi Shar", the dose of vitamins in which makes 50-90% from recommended daily consumption, and "Vitabalance 2000", the contents of vitamins in which at 2-17 of time exceeds need of organism. The use of both additives within 3 weeks resulted in increase of levels of vitamins C, A, E, B2, B6 and carotenoids in blood serum. However if in case of consumption of a drink an authentic level was reached only for vitamin C and beta-carotene, in a case "Vitabalance 2000" for all investigated vitamins except vitamin A. Thus, if the consumption of a drink has lowered frequency of deficiency of 3-4 vitamins, but has not allowed to liquidate it completely, in case of "Vitabalance 2000" consumption the simultaneous deficiency 3-4 vitamins. The received data allow to believe the biologically active food additives containing vitamins in amounts exceeding recommended consumption, are convenient for fast liquidation of hypovitaminoses, and the preparations containing vitamins in doses making 30-50% from need of organism, are acceptable for daily filling of insufficient consumption of vitamins with a usual diet for a long time.

Low intakes of vegetables and fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults

OBJECTIVE

To determine vitamin C intakes among adults and to identify differences in dietary intake associated with vitamin C consumption.

DESIGN

This cross-sectional study compared vitamin C intake, nutrient intake, and food group choices of adults with low (<30 mg/d), marginal (30-60 mg/d), and desirable (>60 mg/d) vitamin C intakes.

SUBJECTS

Data from 2472 men and 2334 women aged 25-75 y were obtained from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII).

RESULTS

Overall, 18% of the sample had low vitamin C intakes, 24% had marginal intakes, and 58% had desirable intakes. In addition to consuming less vitamin C, adults with low vitamin C intakes consumed significantly less (P</=0.001) energy-adjusted (ie nutrient/1000 kcal) folate, fiber, beta-carotene, and vitamin B6, and significantly more (P<0.001) fat. Compared to adults with low intakes, adults with desirable vitamin C intakes consumed significantly more (P</=0.001) high-vitamin C fruit juice and low-vitamin C vegetables, while consuming significantly less (P</=0.009) soft drinks, coffee/tea and alcoholic beverages. On average, adults with desirable vitamin C intakes consumed more than five daily servings of vegetables and fruits, of which more than one was citrus. Adults with low and marginal vitamin C intakes consumed less than one-fifth of a serving of citrus.

CONCLUSIONS

A considerable number of adults under-consume vitamin C and total vegetables and fruits. Nutritionists should continue to promote five to nine daily servings of vegetables and fruits, at least one of which should be rich in vitamin C.

[Vitamin C in medicine: "normal concentration" in serum]

Vitamin C functions in a human organism have been discussed. Connection with many diseases and its systemic deficiency has been emphasized. A review of current application of this vitamin in medicine has been made. Problems accompanying the use of reference sources of vitamin C "normal concentrations" in blood plasma have been characterised. 10 ranges of concentrations given by medical handbooks and textbooks have been compared in detail with 15 parallel ranges taken from scientific papers, paying attention to their significant discrepancies. Basing on source values, performing basic statistical calculations, a reliable mean range of vitamin C "normal concentrations" in blood plasma has been obtained: 36.1-79.4 mumol/l.

[Antioxidative vitamins and cataracts in the elderly]

Senile cataract indicates the opacity of ocular lenses occurring in old and especially in very old people. Lens proteins are extremely long-living and often show oxidative damages. Aging and smoking appear to be the greatest risk factors for the development of lens opacities. The sufficient antioxidant protection of young lenses decreases with the aging process. Consequently, the importance of other protective factors increases. Nutritional factors, particularly vitamins with antioxidant properties, may influence the development of senile cataracts in the ocular lens. Meanwhile an association between the supply with vitamin C, E and beta-carotene and the risk of cataract development was demonstrated in animal studies and also in an increasing number of epidemiological studies. These epidemiological studies mainly support the hypothesis that higher vitamin intakes reduce the risk of developing cataracts in old age. The antioxidant properties of the named nutrients give a plausible explanation for the mechanism of cataractogenesis. On the basis of the present data definitive recommendation, necessary for cataract prevention can not yet be established. Some results seem to support higher recommendations. At the moment several large human intervention trials are carried out. Form these studies a further confirmation of the antioxidant hypothesis and of a dose-response-relationship are expected.

[The vitamin allowance of the pupils in a rural vocational and technical school and their prophylactic vitaminization]

The actual nutrition and providing with vitamins C and B1 was studied in boys aged 16-17 years, students of a rural trade school (Volsk of Saratov Province). Although the caloric value of their ration was high enough the content of animal proteins was only 42-48 g/day. The content of ascorbic acid in the ration comprised 48%, in the spring of 1987 it was 17%, and of 1988-29% of the recommended standard, vitamin B1 levels did not show seasonal differences. Vitamin C and B1 deficiencies in the spring were proved by their low excretion levels in urine, and by a low concentration of vitamin C and decreased activity of B1-dependent enzyme transketolase in the blood. Intake of "Undevitum" (1 dragee/day) during 4 months was conductive to the improvement of the student providing with vitamins.

[Biochemical indicators of vitamin provision to Orenburg's schoolchildren and effectiveness of prophylactic vitamin administration]

The study of providing with vitamins of schoolchildren in Orenburg conducted in the spring of 1985-1986 has revealed decreased content of ascorbic acid in 92%, vitamin E in 62%, vitamin A in 39%, folic acid in 38%, vitamin B12 in 14% of the children, the incidence rate of vitamin deficiency among the children in the senior forms was higher as compared to that in the junior forms and in boys it was more frequent than in girls. Additional intake of multivitamin "Undevitum" by schoolchildren during 2-4 months led to a significant improvement of their providing with vitamins that was expressed in normal vitamin levels and elimination of cases of deep vitamin deficiency.

[A comparative study of vitamin status of children 5-6 years of age in different children's institutions]

A total of 205 children were under observation (48 children aged 1.5-3 years in a Baby's Home--spring, 1987; 85 children aged 3-6 years in nurseries with 24-hour stay--spring, 1987; 77 children aged 3-6 years in a Children's Home--spring, 1989). As a result of nutrition reorganization in these institutions vitamin consumption increased due to a more rational selection of food products and the vitamin status of children improved. This was more expressed in vitamin excretion levels, than in the incidence rate of microsymptoms of vitamin deficiency. Additional vitaminization with multivitamin compounds is necessary to eliminate vitamin deficiency in preschool children of isolated institutions.

L-ascorbyl-2-monophosphate has equal antiscorbutic activity as L-ascorbic acid but L-ascorbyl-2-sulfate is inferior to L-ascorbic acid for channel catfish

Channel catfish (Ictalurus punctatus) fingerlings (13 g average initial weight) were fed semipurified diets supplemented with 0, 0.06, 0.12, 0.24 and 0.72 mmol/kg (0, 11, 22, 44 or 132 mg/kg) of ascorbic acid molar equivalent supplied by either L-ascorbic acid, L-ascorbyl-2-monophosphate (Mg salt) (AAP), or L-ascorbyl-2-sulfate (K salt) (AAS). After 14 wk, weight gains were equal for all fish fed diets containing L-ascorbic acid or AAP; however, growth rates were less for fish fed AAS at all dietary levels and for fish fed the ascorbic acid-free diet (control). There were no gross signs of vitamin C deficiency in any of the fish fed L-ascorbic acid or AAP, whereas spinal deformities were found in the controls and in fish fed all but the highest concentration of AAS. The percentage of spinal deformities decreased as dietary levels of AAS increased. Reduced bone collagen content and histopathology in liver and gill tissues also indicated ascorbic acid deficiency in the controls and in fish fed all but the highest concentration of AAS. Limited histopathology was found in fish fed the lowest level of L-ascorbic acid but not in those fed the lowest level of AAP. Regression analysis of weight gain data showed that the vitamin activity of ascorbic acid from AAS was only 5.2% of that from L-ascorbic acid for growth. This study indicates that AAP has equimolar activity to L-ascorbic acid as a vitamin C source for channel catfish and that AAS has vitamin activity for this species but at a much lower level than the other compounds.

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.

[Prevention of combined iron-polyvitamin deficiency in female workers in the machine-building industry]

The results have been presented of the study of ferrokinetic values and providing with ascorbic and folic acids, vitamins B2 and B12 in women with latent iron deficiency, before and after preventive measures with the use of the lactic acid product "Biolact" combined with the polyvitamin "Gendevitum". The data obtained have shown that latent iron deficiency is attended by vitamin deficiency. "Biolact" enriched with iron and ascorbic acid, combined with "Gendevitum" normalizes iron metabolism and vitamin providing.

Vitamin C status in chronic schizophrenia

Schizophrenic patients on the same hospital diet as control group subjects had significantly lower levels of fasting plasma vitamin C (p less than 0.05) and 6-hr urinary vitamin C excretion after an ascorbic acid load test (p less than 0.01). After administration of 70 mg of ascorbic acid for 4 weeks there was no longer any difference in plasma vitamin C levels between schizophrenics and control group subjects, but the urinary vitamin C excretion after the vitamin C loading test remained significantly lower in schizophrenics (p less than 0.05). The administration of 1 g ascorbic acid for 4 weeks, in addition to eliminating differences in the plasma vitamin C level, also increased the urinary vitamin C excretion of schizophrenic patients to the level of the control group subjects. The results of this study are in agreement with the hypothesis that schizophrenic patients require higher levels of vitamin C than the suggested optimal ascorbic acid requirement for healthy humans.

[Supply of vitamins C and B1 of students attending a rural professional-technical school in the middle Volga region]

Actual nutrition and providing with vitamins C and B1 was studied in boys aged 16-17 years--students of a rural trade school in the town of Volsk, the Saratov region. Although the fuel value of their ration was sufficient (2900-3000 Kcal), the content of animal proteins comprised at an average 42 g/day. The content of ascorbic acid in the ration (evaluated by the analytical method) comprised 48% (in autumn) and 17% (in spring) of the recommended standard; the level of vitamin B1 did not differ depending on the season on the year. In spring, vitamin C and B1 deficiency detected in the students was proved by their low excretion with urine, as well as by a lowered level of vitamin C and low activity of B1-dependent transketolase enzyme in the blood of the subjects studied.

Vitamin C status in 137 outpatients with Crohn's disease. Effect of diet counseling

Vitamin C intake, and serum and leukocyte ascorbate levels were assessed serially over 6 months in 137 outpatients with Crohn's disease. Vitamin C intake was low in 18% of males and 37% of females. Serum ascorbate levels were suboptimal in 11% of males and 18% of females. Leukocyte ascorbate levels were low in 26% of males and 49% of females. Serum ascorbate levels were more frequently below the reference range in patients who smoked, but neither the serum nor the leukocyte ascorbate levels were affected by Crohn's disease activity, the use of an oral contraceptive agent, or by taking prednisone or sulfasalazine. Monthly diet counseling sessions significantly increased vitamin C intake, led to more patients consuming a normal ascorbate intake, and to a normalization of serum ascorbate values. We did not establish the importance of these ascorbate abnormalities on the clinical course of Crohn's disease. We conclude that low serum or leukocyte ascorbate levels are relatively common in patients with active or inactive Crohn's disease; these abnormalities are due in part to the reduced intake of dietary ascorbate; and the ascorbate status in patients with Crohn's disease may be normalized by improving the dietary intake of vitamin C.

Vitamin C status of elderly men in a residential home

The vitamin C status of 35 men, over 70 years of age from a residential home has been studied by measuring the plasma and leucocyte vitamin C levels and by assessing the intake of vitamin C. The mean plasma vitamin C level of the group was 16 +/- 15 mumol/l which was significantly lower (P less than 0.005) than that of a similar group of elderly men living alone (26 +/- 20 mumol/l). The mean leucocyte vitamin C levels of the two groups did not differ significantly. Twenty-nine (83 percent) of the institution group had plasma vitamin C levels below 23 mumol/l and 13 men (37 percent) had leucocyte vitamin C levels below 10 microgram/10(8)WBC. The residents who supplemented the institution diet with their own fresh fruit supplies had higher plasma and leucocyte vitamin C levels than the men who did not (P less than 0.01). Some clinical signs possible related to vitamin C deficiency were recorded but these could not later be statistically related to either plasma or leucocyte vitamin C levels. A case is made for vitamin C supplementation of puddings in institutional meals for the elderly.

Effect of vitamin C supplementation on black mineworkers

Subclinical vitamin C deficiency frequently occurs in Black mineworkers, in spite of an apparently adequate daily intake. A study was undertaken to establish the minimum rate of supplementation that would effectively reduce the incidence of subclinical vitamin C deficiency. Two levels of supplementation were tested in relation to a control group. It was found that a supplementation rate of at least 235 mg/head/day is required to maintain reasonably adequate serum levels. It was also found that effective control measures are required to ensure that the supplement is added to the magou, the staple beverage of the miners. It is strongly recommended that the intake of every Black mineworker be supplemented at a rate of 200 - 250 mg/day.