Essential role of vitamin C and zinc in child immunity and health.

With the progressive elimination of dietary protein-energy deficits, deficiencies of micronutrients are emerging as the limiting factors in ensuring children's optimal health. Data from several countries in Asia and Latin America indicate that deficiencies of vitamin C and zinc continue to be at alarming levels. This article reviews the roles of vitamin C and zinc in supporting children's growth and development, with a particular focus on the complementary roles they play in supporting immune functions and combating infections. The contemporary relevance of vitamin C and zinc deficiency in the Asian and Latin American regions, both undergoing a rapid nutritional transition, are also discussed. Overall, there is increasing evidence that deficiency of vitamin C and zinc adversely affects the physical and mental growth of children and can impair their immune defences. Nutrition should be the main vehicle for providing these essential nutrients; however, supplementation can represent a valid support method, especially in developing regions.

Recommended dietary allowance: support from recent research.

Increasing evidence is accumulating that a synergistic role of the so-called antioxidant vitamins (C, E, beta-carotene) may have a dominant role in the prevention of cancer, cardiovascular diseases and cataract formation. Controversy still exists regarding the optimum intake of vitamin C. This is partly due to lack of accurate and easily accessible health-relevant end-points, and lack of knowledge of the role of vitamin C in biochemical functions. Today, it is clearly recognized and broadly accepted that optimal health is a consequence of dietary optimization. Attainment of optimal health rather than prevention of deficiency symptoms is the goal. There can be little doubt that in this respect the requirements for vitamin C are greater than the amount required for the mere prevention of overt or classical scurvy. The recommendation of varying levels of requirement could overcome the controversy. The following is therefore proposed: The lowest level is that value which prevents deficiency symptoms. The second level is valid for healthy populations (< 200 mg/d). This level would take into account needs which differ according to age, sex, physical activity, physiological status (e.g. pregnancy or lactation) and environmental factors such as smoking, pollution and alcohol intake. Finally, a third level should be determined for the prevention of the above-mentioned non-communicable diseases. These diseases are an important cause of disability, resulting in costs of billions of dollars annually in medical costs. Many of the above-mentioned diseases can be prevented by supplementation with vitamin C. Medical costs could thereby also be dramatically reduced.

[Complications in pancreatic duct occlusion: passage of the occlusant into the venous system]. / Komplikation bei der Pankreasgangocclusion: Ubertritt der Füllungsmasse in das venöse System.

In two cases, occlusion of the residual pancreas remaining after a Whipple's procedure was associated with a "spillover" of the occlusant into the venous system of the pancreas, resulting in one of the cases in embolisation of intrahepatic branches of the portal vein. In both cases, the parenchyma of the residual pancreas was well preserved. The cause of the spillover into the venous system was the injection of a too large volume into the ductal system, with subsequent rupture of small side branches. To avoid this rare complication, the filling of the ductal system should be carried out under intraoperative radiological control.

The role of ascorbic acid in carcinogenesis.

Vitamin C is an essential nutrient whose protective role in carcinogenesis has been discussed for more than 50 years. Epidemiologic studies suggest that the consumption of vitamin C-rich foods is associated with a lower risk of cancers of the esophagus and stomach. The observation that cancer patients have low leukocyte vitamin C levels led to therapeutic trials the results of which are controversial; the hypothesis that vitamin C acts like a drug must be questioned. On the other hand, ascorbic acid interacts with various tumor-inducing compounds, such as the precursors of N-nitroso compounds, to prevent the formation of tumors. Experiments with animals and cell cultures indicate that ascorbic acid can interfere with the metabolism of tumor promoters. It has also been postulated that ascorbic acid helps to prevent cancer by enhancing cellular immunity. In general, evidence suggests that vitamin C can inhibit the formation of some carcinogens.

Ethanol selectively affects Na+-gradient dependent intestinal transport systems.

Moderate concentrations of ethanol reduce the velocity of uptake of three representative Na+-symport systems (D-glucose, L-alanine, L-ascorbate), whether electrogenic (the first two) or electroneutral (L-ascorbate). This 'inhibition' is observed only if these transport systems are tested in the presence of an initial Na+ gradient (out greater than in); no inhibition is found in tracer-equilibrium exchange measurements. A representative Na+-independent system (D-fructose) is not inhibited by ethanol. 'Passive diffusion' (measured as uptake of L-glucose) is increased somewhat by alcohol. All these observations can be rationalized [as suggested by Tillotson et al. (1981) Arch. Biochem. Biophys. 207, 360-370] by an effect of ethanol on passive diffusion, which leads to a faster collapse of the Na+ gradient, with the resulting reduction of the uptake velocities of Na+-dependent transport systems when tested with the added driving force of an Na+ out----in gradient.

Formation of carbon dioxide from ascorbate in man.

Volunteers were given a steady intake of various individually different daily dosages of ascorbic acid. After 3 weeks 1-14C-labelled ascorbate was given together with various amounts of unlabelled ascorbic acid (90-1000 mg). Regardless of the total daily dose in cases where the carrier dose amounted to 180 mg or more, carbon dioxide was recovered from the breath. The amount recovered ranged from 1 to more than 30% of the given dose. The larger the amount of carrier the larger was the amount of label recovered as carbon dioxide. It is suggested that the formation of carbon dioxide is due to a presystemic effect as a result of microbiological or chemical degradation of ascorbate in the intestine.

[Cerebrospinal fluid and plasma levels of vitamin C in children]. / Vitamin-C-Konzentrationen in Liquor und Plasma von Kindern.

Vitamin C (ascorbic acid) levels in cerebrospinal fluid (CSF) and plasma from 67 children, in whom lumbar puncture had to be performed for medical reasons, are reported in this preliminary paper. 14 children of this group show normal CSF laboratory values and serve as controls. Vitamin C concentrations in CSF of controls are on average 2.5-3-times higher (30.1 +/- 6.3 mg/l) than the pertaining values in their plasma (12.2 +/- 4.9 mg/l). Significant differences are exhibited by premature and term babies, which have up to 16-times higher values of vitamin C in CSF than in plasma. Furthermore CSF vitamin C is 4-5 times higher in premature babies than in schoolchildren of our group (118.2 +/- 65.9 versus 28.3 +/- 3.0 mg/l). Another interesting finding in this study is a significant decrease of CSF vitamin C in cases of acute purulent meningitis (12.3 +/- 4.8 versus 30.1 +/- 6.3 mg/l, p less than 0.05). These results, in connection with reports about high vitamin C concentrations in brain tissue, particularly in prematures, make one suspect important functions of this vitamin in physiological and pathological mechanisms in the central nervous system.

Penetration of cefmenoxime into serum, gynecologic tissues, and heart valves.

Twenty-nine women received 7 g of cefmenoxime before abdominal or vaginal hysterectomy; 20 adult patients received 2 g of cefmenoxime 24 hours and immediately before open heart surgery. In the gynecologic patients, peak cefmenoxime serum concentrations of 23.4 mg/liter were reached within one to two hours after administration of the antibiotic. Cefmenoxime concentrations in myometrium, endometrium, and salpinges also reached their peak one to two hours after administration. Two to three hours later tissue concentrations varied between 1.1 and 5.2 micrograms/g; four hours after application, tissue concentrations were below detectable levels. Cefmenoxime plasma and tissue concentrations were significantly higher in patients undergoing open heart surgery. Subcutaneous tissue and muscle concentrations varied between 2.7 and 38.0 micrograms/g. Cefmenoxime concentrations in cardiac valvular tissue were higher than those in muscle and fat.

Phlegmonous gastritis after Indian ink marking.

A report is presented on a case of phlegmonous gastritis following gastroscopic Indian ink injection into the mucosa of the stomach in a 60-year-old woman patient wih early gastric carcinoma. The patient was discharged from hospital on the 11th day after Billroth II resection, in good condition. The necessity for disinfection and sterilization of the instruments employed is emphasized; the continued use of Indian ink marking is recommended.

Studies on the metabolic conversion of ascorbate.

In the intact animal guinea pigs metabolize (1-14C)ascorbic acid much faster to (14C)carbon dioxide (peak exhalation at 30 min) than rats (peak exhalation at 2 to 3 h) following single oral administration, but total excretion was comparable. This finding might be related to the differences in the absorption mechanism of ascorbic acid in these species. The large difference in retention capacity of ascorbic acid in the liver is suggested to be due to multiple recirculation of ascorbic acid in the guinea pig when compared to the rate. Homogenate preparations of rat stomach, small intestine or liver as well as cultured intestinal microbial flora did not cause metabolic degradation on incubation with (1-14C)ascorbic acid to (14C)carbon dioxide. It is therefore suggested that the observed excretion of (14C)carbon dioxide is due to spontaneous non-enzymatical reaction in liver and possible other tissues. Analysis of ascorbic acid metabolites formed on incubation by analytical isotachophoresis suggests that ascorbic acid is a rather stable substrate whereas dehydroascorbate and 2,3-diketogulonic acid are rapidly degraded. This allows the assumption that in vivo metabolism of ascorbic acid might not involve dehydroascorbic acid. Our data do not support the hypothesis that ascorbic acid undergoes presystemic metabolism to carbon dioxide in the intestinal wall.

Metabolism and requirements of ascorbic acid in man.

The metabolism and absorption of ascorbic acid in man are reviewed. The daily requirement of ascorbic acid in male non-smoking volunteers was studied by following the kinetics of a single dose of (1-14C) ascorbic acid under steady-state conditions. A diet low in vitamin C and daily supplements of ascorbic acid (30-180 mg) were given. The time course of elimination of radioactivity from plasma and urinary excretion data were used to calculate kinetic parameters. The overall half-life was calculated as 10 - 20 days and is dependent of plasma ascorbate levels. The body pool approached 20 mg/kg body weight at a plasma ascorbate concentration of 0.9 mg/dl and was maintained by a total turnover of 60 mg/d. The necessary daily intake of ascorbic acid to match this turnover is 70-80 mg, since absorption is incomplete (80-90%). Therefore, to cover at least 95% of the non-smoking male population a daily intake of 100 mg ascorbic acid is required. Similar studies have been carried out in smokers known to have lowered plasma ascorbate levels. Results suggest that the requirement of ascorbic acid is increased in smokers--a daily intake of 140 mg ascorbic acid is thought to be adequate non-smoking male population a daily intake of 100 mg ascorbic acid is required. Similar studies have been carried out in smokers known to have lowered plasma ascorbate levels. Results suggest that the requirement of ascorbic acid is increased in smokers-a daily intake of 140 mg ascorbic acid is thought to be adequate.

On the requirements of ascorbic acid in man: steady-state turnover and body pool in smokers.

The time course of radioactivity in plasma and urine after oral administration of a single dose of (1-14 C) ascorbic acid has been followed in healthy male volunteers smoking more than 20 cigarettes per day. The investigation was carried out under steady state conditions with regard to ascorbic acid plasma levels at intakes of about 30 to 180 mg/day. Smokers had a higher metabolic turnover than that found for nonsmokers. It was concluded, as a consequence, that a daily intake of at least 140 mg is required for smokers to reach steady state concentrations and total body pools comparable to nonsmokers for whom a daily intake of about 100 mg was previously reported to be appropriate.

Urinary oxalate excretion after large intakes of ascorbic acid in man.

The influence of high dose intake of ascorbic acid on the urinary excretion of oxalate was investigated in five healthy male volunteers. Oxalate was measured by a newly developed specific method using isotachophoresis. With intakes of 10 g ascorbic acid (5 X 2 g daily for 5 days; four subjects) mean urinary oxalate excretion was enhanced from about 50 mg to 87 mg (range 60 to 126 mg) per day. At least 25% of the ascorbic acid was absorbed and excreted with the urine. On discontinuing ascorbic acid administration, oxalate excretion returned to baseline values within 24 h. The time-course of oxalate excretion revealed that following the 3rd dose of 2 g ascorbic acid a plateau in urinary oxalate excretion was reached (0.6 microgram ml-1 min-1) which was not exceeded despite additional 2-g doses of ascorbic acid. On termination of ascorbic acid administration the oxalate excretion rate remained at this level for a further 6 h and then decreased to prestudy rates. No effect of high-dose ascorbic acid ingestion was found on the daily urinary excretion of creatinine, uric acid, and inorganic phosphate. Calcium excretion was slightly reduced. In comparison to the large amounts of ascorbic acid ingested, the increase in urinary oxalate excretion as measured by isotachophoresis in these healthy male volunteers was very low, and is thus similar to the change in urinary content of oxalate which results from consuming normal diets.

Food patterns in modern society and their consequences on nutrition.

In conclusion we may state that a borderline vitamin deficiency exists in many population groups as well as in single persons even in industrialized countries. The reason for this fact is mainly the low education which is often associated with a low socioeconomic status and certain food patterns which derive from tradition, emotion or from other reasons not yet well understood. We have proved that the avoidance of pork and whole-wheat bread leads to a borderline vitamin B1 deficiency and the avoidance of citrus fruits, fruits, vegetables, viscera and potatoes to a broderline vitamin C deficiency. On the other hand, preference of meat did not show any adverse effect in respect to the vitamin B6 status. We believe that this kind of studies has to be continued, since the aim of nutritional surveys should consist in improving the nutritional status of the general population or of population groups. Therefore, it should be investigated why in certain population groups poor nutrition exists. Only the answer to this question could help us to combat malnutrition in industrialized countries in the best way.