Systemic Biomarkers and Liver Morphology in Rats during Chronic Low-Dose Toxicant Administration against the Background of Vitamin Deficiency

Liver morphology, intensity of apoptosis, and activity of xenobiotic metabolism enzymes were studied in a chronic model experiment in rats receiving a mixture of 6 pesticides against the background of life-long diets with adequate and insufficient supply of water-soluble vitamins. The dose of each pesticide in the mixture did not exceed the acceptable daily intake (1 ADI). It was found that chronic exposure to low doses of anthropogenic toxicants in combination with permanent vitamin deficiency provokes a number of liver changes, such as increased apoptosis activity, cytochrome P450 system depletion, steatosis, and inflammatory infiltration, which is a potential health risk factor.

Should We Consider the Cardiovascular System While Evaluating CKD-MBD?

Cardiovascular (CV) disease is highly prevalent in the population with chronic kidney disease (CKD), where the risk of CV death in early stages far exceeds the risk of progression to dialysis. The presence of chronic kidney disease-mineral and bone disorder (CKD-MBD) has shown a strong correlation with CV events and mortality. As a non-atheromatous process, it could be partially explained why standard CV disease-modifying drugs do not provide such an impact on CV mortality in CKD as observed in the general population. We summarize the potential association of CV comorbidities with the older (parathyroid hormone, phosphate) and newer (FGF23, Klotho, sclerostin) CKD-MBD biomarkers.

General Adaptation in Critical Illness: Glucocorticoid Receptor-alpha Master Regulator of Homeostatic Corrections

In critical illness, homeostatic corrections representing the culmination of hundreds of millions of years of evolution, are modulated by the activated glucocorticoid receptor alpha (GRα) and are associated with an enormous bioenergetic and metabolic cost. Appreciation of how homeostatic corrections work and how they evolved provides a conceptual framework to understand the complex pathobiology of critical illness. Emerging literature place the activated GRα at the center of all phases of disease development and resolution, including activation and re-enforcement of innate immunity, downregulation of pro-inflammatory transcription factors, and restoration of anatomy and function. By the time critically ill patients necessitate vital organ support for survival, they have reached near exhaustion or exhaustion of neuroendocrine homeostatic compensation, cell bio-energetic and adaptation functions, and reserves of vital micronutrients. We review how critical illness-related corticosteroid insufficiency, mitochondrial dysfunction/damage, and hypovitaminosis collectively interact to accelerate an anti-homeostatic active process of natural selection. Importantly, the allostatic overload imposed by these homeostatic corrections impacts negatively on both acute and long-term morbidity and mortality. Since the bioenergetic and metabolic reserves to support homeostatic corrections are time-limited, early interventions should be directed at increasing GRα and mitochondria number and function. Present understanding of the activated GC-GRα's role in immunomodulation and disease resolution should be taken into account when re-evaluating how to administer glucocorticoid treatment and co-interventions to improve cellular responsiveness. The activated GRα interdependence with functional mitochondria and three vitamin reserves (B1, C, and D) provides a rationale for co-interventions that include prolonged glucocorticoid treatment in association with rapid correction of hypovitaminosis.

Micronutrient Depletion in Heart Failure: Common, Clinically Relevant and Treatable

Heart failure (HF) is a chronic condition with many imbalances, including nutritional issues. Next to sarcopenia and cachexia which are clinically evident, micronutrient deficiency is also present in HF. It is involved in HF pathophysiology and has prognostic implications. In general, most widely known micronutrients are depleted in HF, which is associated with symptoms and adverse outcomes. Nutritional intake is important but is not the only factor reducing the micronutrient availability for bodily processes, because absorption, distribution, and patient comorbidity may play a major role. In this context, interventional studies with parenteral micronutrient supplementation provide evidence that normalization of micronutrients is associated with improvement in physical performance and quality of life. Outcome studies are underway and should be reported in the following years.

The Role of the Status of Selected Micronutrients in Shaping the Immune Function

OBJECTIVE

This narrative review gives an overview on the essential role of adequate nutrition to an optimally functioning immune defence. Micronutrients act as regulators of the immune response, with the focus of this review on the immunomodulatory effects of the trace elements iron, zinc and selenium, and the vitamins A, D, E, C, B6 and B12 and folic acid.

RESULTS

Iron deficiency especially impairs the Th1 cell-borne cellular immunity. T lymphocytes are also most affected by a deficiency of zinc, needed for their maturation and the balance between the different T cell subpopulations and acting as a redox signal in the regulation of many enzymes. Selenium is also involved in redox reactions as the glutathione peroxidases and other redox enzymes are selenoproteins. Selenium status has shown special effects on cellular immunity and resistance to viral infections. Vitamin A in the form of retinoic acid induces a humoral Th2 cell response via antigen-presenting cells and is involved in maintaining intestinal immune defence and tolerance through its nuclear receptor RAR and via kinase signalling cascades. Immune tolerance is particularly promoted by vitamin D acting through dendritic cells to stimulate the differentiation of regulatory T cells. Vitamin E has antiinflammatory effects and stimulates naïve T cells especially in the elderly. Besides its antioxidative properties, vitamin C has effects on cell signalling and epigenetic regulation. The B vitamins are required for cytotoxic cellular immunity and modulate T cell responses.

CONCLUSION

A diverse diet and regular exposure to sunlight are the best sources for a balanced nutrient supply to maintain an optimal immune defence.

Prolonging healthy aging: Longevity vitamins and proteins

It is proposed that proteins/enzymes be classified into two classes according to their essentiality for immediate survival/reproduction and their function in long-term health: that is, survival proteins versus longevity proteins. As proposed by the triage theory, a modest deficiency of one of the nutrients/cofactors triggers a built-in rationing mechanism that favors the proteins needed for immediate survival and reproduction (survival proteins) while sacrificing those needed to protect against future damage (longevity proteins). Impairment of the function of longevity proteins results in an insidious acceleration of the risk of diseases associated with aging. I also propose that nutrients required for the function of longevity proteins constitute a class of vitamins that are here named "longevity vitamins." I suggest that many such nutrients play a dual role for both survival and longevity. The evidence for classifying taurine as a conditional vitamin, and the following 10 compounds as putative longevity vitamins, is reviewed: the fungal antioxidant ergothioneine; the bacterial metabolites pyrroloquinoline quinone (PQQ) and queuine; and the plant antioxidant carotenoids lutein, zeaxanthin, lycopene, α- and β-carotene, β-cryptoxanthin, and the marine carotenoid astaxanthin. Because nutrient deficiencies are highly prevalent in the United States (and elsewhere), appropriate supplementation and/or an improved diet could reduce much of the consequent risk of chronic disease and premature aging.

Impact of opioids on oxidative status and related signaling pathways: An integrated view

BACKGROUND

Opioids produce reactive oxygen species (ROS) which are highly reactive molecules that damage cells and tissues, and are suggested to contribute to the opioid use disorders. Thus, antioxidant supplementation might improve the disturbance in redox (oxidation-reduction) homeostasis. However, randomized trials on antioxidant therapy have not shown beneficial effects.

OBJECTIVES

The purpose of this review is to shed lights on the oxidative changes resulting from opioid use and to highlight the unanswered questions regarding oxidative profile in an effort to provide a comprehensive view of different aspects of an efficient antioxidant therapy in clinical settings.

METHODS

The studies were identified and gathered from the PubMed database over the past 16 years (2000-2016). Our search results were limited to articles in English, both animals and human and in vitro and in vivo studies. A total of 50 full text articles were reviewed and summarized.

RESULTS

Opioids elevate the level of ROS and decrease the function of enzymatic antioxidants such as superoxide dismutase, catalase, and glutathione peroxidase. They increase the risk of vitamin deficiency and modify gene expression of target cells through ROS production. The effects of opioids on their target cells are exerted through different way and various mechanisms.

CONCLUSION

Opioids modulate the redox homeostasis; therefore, understanding the profile of oxidative changes in individuals with opioid use disorder could be of significant benefits in the clinical setting, to help with selection of an efficient antioxidant therapy and diminishing oxidative damage.

[MALABSORPTION FAT-SOLUBLE VITAMINS AND PROSPECTS OF THEIR USE IN LIVER DISEASES]

In a review article considers issues of efficiency and tactics of the purpose of fat-soluble vitamins, as in cholestatic and noncholestatic liver disease, as well as water-soluble vitamins, particularly vitamin C cholelithiasis. Oxidative stress due to chronic inflammation is one of the major conversion mechanisms of liver fibrosis in cirrhosis. The imbalance between production of reactive oxygen species and antioxidant defense causes a number of pathophysiological changes in the liver, including activation of hepatic stellate cells. The carriers of the I148M PNPLA3 mutation was not observed concentration reduction in liver vitamin A with increasing severity of the disease, but the observed decrease in the level of circulating retinyl palmitate and retinol-binding protein. To the appointment of vitamin A in liver disease should be approached with caution. Hypervitaminosis A leads to accelerated liver fibrosis and stimulates carcinogenesis. Currently actively studied the possibility of using vitamin E as an antioxidant, in patients with non-alcoholic fatty liver disease. His presence in the membranes phospholipid bilayer allows cells to prevent non-enzymatic oxidation of cell components by free radicals. Vitamin E can suppress the profibrotic processes. In patients with chronic cholestatic liver disease is common, vitamin K deficiency, even when administered, and is associated with the degree of cholestasis and severity of disease. The vitamin D deficiency, liver disease is also associated with the severity of disease correlated with the severity of liver failure and infectious complications. Vitamin D is an independent prognostic parameter for mortality risk in patients with liver cirrhosis.

[Effects of dietary fibers on hepatocyte apoptosis in rats with alimentary polyhypovitaminosis]

The effect of dietary fibers (DF) of wheat bran on hepatocyte apoptosis in rats adequately provided with vitamins or insufficiently supplied with vitamins has been investigated. 48 male Wistar rats (initial body mass--58.1 +/- 0.5 g) were randomly divided into 6 groups and fed with semi-synthetic diet, containing 100% or 20% of vitamin mixture (Vit) with or without addition of DF in the dose corresponding to the upper allowable level of its consumption (5% of diet mass) for 4 weeks. The animals of the 1 group received 100% of vitamin mixture (100% Vit); 2 group--100% Vit + DF; 3 group--20% of vitamin mixture with full exclusion of vitamins E, B1 and B2 (20% Vit); 4 group--20% of vitamin mixture and DF (20% Vit + DF). The next 5 days rats from vitamin-deficient groups were fed with diets supplemented with 80% of vitamins from their content in control group: (5 group--20% Vit + 80% Vit; 6 group--20% Vit + DF + 80% Vit). The suspension of hepatocytes was received by Becton Dickinson Medimachine System (USA). Hepatocyte apoptosis was assessed by the method of flow cytometry using Beckman Coulter FC 500 (USA) cytometer by stained cells with Annexin V-FITC/ 7-Amino-Actinomycin D Kit (Beckman Coulter, USA). In rats fed complete semi-synthetic diet supplemented with DF (100% Vit + DF) the hepatocyte apoptosis was higher by 22% (p < 0.10) than that in rats of control group (4.99 +/- 1.82%). In rats fed diets with low vitamin content (groups: 20% Vit and 20% Vit + DF) the hepatocyte apoptosis was significantly higher (p < 0.05) than that in the control group and reached 7.03 +/- 1.74 and 7.26 +/- 1.13% accordingly. Normalization of vitamin content in the diets of rats from deficient groups during 5 days had no effect on the severity of apoptosis regardless from presence (8.02 +/- 2.18%) or absence of the DF (8.04 +/- 1.66%). Adding DF in dose corresponding to the upper allowable level of consumption, on the background of adequate vitamin content in the diet is accompanied by a tendency to develop hepatocyte apoptosis, which may be the result of a direct action of short chain fatty acids generated from the DF and the deterioration of vitamin sufficiency.

[Correction of the combined vitamin deficiency in growing rats fed fiber enriched diets with different doses of vitamins]

The effect of 5% dietary wheat bran (WB) on the correction of combined vitamin deficiency by two doses of vitamins (physiological and enhanced) has been analyzed using a rat model (8 groups, n = 8/group). Vitamin deficiency in male weanling Wistar rats (58.1 ± 0.5 g) was induced by 5-fold reduction of vitamin mixture amount in the feed and complete vitamin E, B1 and B2 exclusion from the mixture for 30 days, then deficit was corrected within 5 days. Rats from control group were fed a complete semisynthetic diet containing microcrystalline cellulose 2%. Vitamin deficient diet for 35 days resulted in reduced (p < 0.05) levels of vitamin A in the liver by 25 fold, vitamin E and B1--2.0-2.3 fold, vitamin B2--by 40%, 25(OH)D blood plasma concentration--by 21% compared with the control. Feed consumption of the animals treated with vitamin deficient diet and WB was higher by 43% than in rats with vitamin deficit. Their rate of weight occupied the intermediate position between the rates of weight in deficit and in control animals, and they could not serve a full control to evaluate the WB impact on vitamin sufficiency. After filling the vitamin diet content to an adequate level vitamin E liver content was fully restored. To restore vitamins B1 and B2 liver level higher doses of vitamins (120-160% of adequate content) were required, and to restore the reduced levels of vitamin A in rat liver even 2-fold increased dose of vitamin A was insufficient. The diet enrichment with WB had no effect on vitamin B1 and B2 liver content, regardless of the amount of vitamins in the diet. Adding fiber to the diet of animals adequately provided with vitamins resulted in significantly 1,3-fold increase of 25(OH)D blood plasma concentration and a slight but significant decrease of α-tocopherol liver level by 16% as compared to rats not receiving WB. The enrichment of rat diet with dietary fibers worsened restoration of the reduced vitamin E status not only by filling vitamin content in the diet to an adequate level, but also by using 2-fold enhanced dose of vitamin. Within 5 days deficiency of vitamins A, B1, B2 was not eliminated with increasing vitamin diet content to an adequate level. Higher doses of vitamins are needed for the complete correction of vitamin status. The addition of vitamins to an adequate level was sufficient to normalize the elevated liver levels of MDA in rats with combined vitamin deficiency that may be associated with vitamin E status improvement. The diet enrichment with fiber did not affect on the intensity of lipid peroxidation in rat liver regardless of their provision with vitamins.

Biochemistry of blood plasma and some parameters of antioxidant status in rats with polyhypovitaminosis of varying severity

In rats with profound vitamin deficiency, blood plasma level of triglycerides significantly decreased by 1.6 times, potassium ions by 5%, uric acid by 23%, ALT and AST by 1.4 times, while the levels of glucose increased by 32%, iron by 31%, urea by 58%, and alkaline phosphatase by 19%. Plasma level of phosphorus tended to decrease and ionized calcium concentration tended to increase. Severe deficiency of all vitamins is accompanied by pronounced accumulation of MDA in the plasma and liver together with simultaneous increase in the level of coenzyme Q10 by 4.6 times and decrease in vitamin C content by 21.4% in the rat liver compared to the control. It was found that severe combined deficiency of vitamins for 4 weeks produced considerable multidirectional alterations in diagnostically important metabolic parameters in rat plasma.

[Vitamins and oxidative stress]

The central and local stress limiting systems, including the antioxidant defense system involved in defending the organism at the cellular and systemic levels from excess activation response to stress influence, leading to damaging effects. The development of stress, regardless of its nature [cold, increased physical activity, aging, the development of many pathologies (cardiovascular, neurodegenerative diseases, diseases of the gastrointestinal tract, ischemia, the effects of burns), immobilization, hypobaric hypoxia, hyperoxia, radiation effects etc.] leads to a deterioration of the vitamin status (vitamins E, A, C). Damaging effect on the antioxidant defense system is more pronounced compared to the stress response in animals with an isolated deficiency of vitamins C, A, E, B1 or B6 and the combined vitamins deficiency in the diet. Addition missing vitamin or vitamins restores the performance of antioxidant system. Thus, the role of vitamins in adaptation to stressors is evident. However, vitamins C, E and beta-carotene in high doses, significantly higher than the physiological needs of the organism, may be not only antioxidants, but may have also prooxidant properties. Perhaps this explains the lack of positive effects of antioxidant vitamins used in extreme doses for a long time described in some publications. There is no doubt that to justify the current optimal doses of antioxidant vitamins and other dietary antioxidants specially-designed studies, including biochemical testing of initial vitamin and antioxidant status of the organism, as well as monitoring their change over time are required.

[Colon lactoflora of rats with alimentary polyhypovitaminosis and modified fat component of diet]

The examination was carried out on male Wistar rats with an initial weight 97-121 g. Influence of vitamin provision and composition of fat component in semisynthetic diet on the condition of lactoflora population of intestine were studied. The deficiency of vitamins was caused by fivefold decrease of amount of vitamin mixture added to the feed and by elimination of vitamin E from this mixture. The modification of fat component was made by substitution of sunflower oil for linseed oil in equal amount (the ratio of vegetable oil and animal fat (lard) was 1:1). Duration of the first phase of the experiment was 28 days. Vitamin deficiency in rats, receiving feed with sunflower oil, was accompanied by significant decrease of vitamins A, E, B1 and B2 in the liver, but did not affect the quantity of lactobacilli in caecum content of rats. Enrichment of the diet deficient in vitamins with polyunsaturated omega 3 fatty acids was associated with a statistically significant increase in number of lactobacilli in the intestine compared with the control group (9.78+/-0.08 opposite 8.82+/-0.33 Ig CFU/g, p=0.018) and group of rats with vitamin deficiency (9.03+/-0.18 Ig CFU/g p = 0.006). On the second stage, replenishment of vitamin deficiency was carried out in the next 14 days by increasing the amount of vitamin mixture to 70 and 200% of vitamin content from a diet in control group. The replenishment has not affected the number of caecum lactobacilli irrespectively of the dose of vitamins and fatty component.

[Effects of polyvitamin deficiency on the activity of xenobiotic-metabolizing enzymes in rat liver]

The activity of xenobiotic-metabolizing enzymes was studied in the liver of male Wistar rats, which were fed for 4 weeks diets, containing 100 (control), 50 and 20% of vitamin adequate level. Moderate (50%) polyvitamin deficiency increased activity of EROD (by 13%), MROD (by 34%; p<0,05), 4-nitrophenol hydroxylase (by 16%), 6beta-testosterone hydroxylase (by 17%), UDP-glucuronosyle transferase (by 26%, p<0,05) and quinone reductase (by 55%, p<0,05). Deep (20%) polyvitamin deficiency decreased in liver activity of MROD (to 78% of control level, p<0,05), 4-nitrophenol hydroxylase (to 74%, p<0,05), heme oxygenase-1 (to 83%, p<0,05) and quinone reductase (to 60%, p<0,05). At the same time a 22% increase in the UDP-glucuronosyle transferase activity compared to the control group was found; activities of EROD, PROD, 6beta-testosterone hydroxylase and the total activity of glutathione S-transferase were unchanged. Deep polyvitamin deficiency had no significant effect on CYP1A1 mRNA and AhR mRNA level, whereas the expression of CYP1A2 mRNA and CYP3A1 mRNA were decreased to 62 and 79%, respectively, as compared with control.

[Effect of dietary fat on vitamin status of rats]

The influence of low (1%) and high (31%) diet fat content (sunflower-seed oil and lard 1:1 at a ratio of 1:1) on vitamin A, E, B1 and B2 status of growing Wistar rats (8 rats per group) with initial body weight 80-100 g has been investigated. The semi-synthetic diet contained vitamin mixture in doses covering the physiological requirement of these animals. The increase of fat content (31%) in the diet due to the presence of vitamin E in sunflower-seed oil automatically lead to 1,7-fold increase consumption of this vitamin compared to the control group. Diet fat content did not affect the level of vitamins B1 and B2 in rat liver. Excessive intake of fat and vitamin E for 6 weeks did not influence on the content of blood plasma vitamin E and rat liver vitamin A occurs at the same time, while significant 1,9 fold elevation of liver vitamin E level and 26 per cent increase of blood plasma vitamin A concentration. The almost complete exclusion of fat from the diet had no effect on blood plasma level of alpha-tocopherol and retinol, but resulted in a significant decrease of vitamins A and E content in rat liver by 40 per cent, indicating a deterioration of sufficiency with these fat-soluble vitamins. The analysis of the results obtained in this investigation and literature data have suggested that under excessive as well as under decreased consumption of fat there is a risk of the development of polyhypovitaminosis. Vitamin complex supplementation is required to prevent a possible worsening of vitamin status under diets with modified fatty component.

Psychological stress and vitamins

Conditions of stress and anxiety have complex interactions with insufficient vitamin intake and malnutrition. This study, based on literature research in Medline, analyzes the inter-relationship between vitamins and stress. This report concerns a number of vitamins that have been receiving much attention in earlier reviews of the literature, for their potential to protect against stress-related events, and focus is placed upon recent findings.

Neurologic complications of bariatric surgery

With the rapid rise in the number of bariatric surgeries performed for morbid obesity, several short- and long-term neurologic complications of this procedure have been identified. These complications affect various levels of the neuraxis, and most are likely secondary to deficiency of essential minerals and vitamins. We report on 3 patients who developed unusual and severe neurologic deficits after undergoing bariatric surgery, including Wernicke encephalopathy, acute and rapidly progressive polyneuropathy, myelopathy, and visual deficits. Two developed clinical features of Parkinsonism, a complication not previously reported in this patient population. None of our patients had attended a nutrition clinic postoperatively. All 3 had a rapid weight loss and intractable vomiting preceding the development of neurologic symptoms, and all were found to have significant vitamin deficiencies. Replacement of vitamins resulted in a slow and variable degree of neurologic recovery. Patients undergoing bariatric surgery should have close monitoring of their nutritional status postoperatively. Routine supplementation of vitamins and minerals may be a cost-effective strategy for preventing neurologic complications in these patients.

[Evaluation of dietary therapy efficiency, based on clinical and biochemical parameters in patients with cardiovascular disease and osteopenia]

Aim of investigation was to analysis of dietary intake in patients with cardiovascular diseases (CVD) and osteopenia. We studied 13 patients with CDV and osteopenia and 117 control subjects with CDV. Analysis of dietary intake in all patients showed high level consumption of fat, excessive consumption of phosphorus and deficiency in consumption of vitamins A, B1, B2. It was shown that diet-therapy has promoted the most positive changes of the clinical, biochemical and immunological parameters of patients had osteopenia less then control group.

Chronic low intake of protein or vitamins increases the intestinal epithelial cell apoptosis in Wistar/NIN rats

OBJECTIVE

Malnutrition decreases antioxidant defense and increases oxidative stress in the intestine. We studied the effects of long-term restriction of food, protein, and vitamins on intestinal epithelial cell (IEC) apoptosis and the underlying mechanisms.

METHODS

Weanling, Wistar/NIN male rats were fed ad libitum with a control diet, 75% protein-restricted diet, or 50% vitamin-restricted diet for 20 wk. The food-restricted group received 50% of the diet consumed by control rats. IEC apoptosis was monitored by morphometry, Annexin V binding, M30 CytoDeath assay, and DNA fragmentation. Structural and functional integrity of the villus were assessed by the ratio of villus height to crypt depth, and alkaline phosphatase and lys, ala-dipeptidyl aminopeptidase activities, respectively. Oxidative stress parameters, caspase-3 activity, and expression of Bcl-2 and Bax were determined to assess the probable mechanisms of altered apoptosis.

RESULTS

Protein and vitamin restrictions but not food restriction significantly increased IEC apoptosis and only vitamin restriction altered structural and functional integrity of villi. Increased levels of protein carbonyls, thiobarbituric acid reactive substances, and caspase-3 activity along with decreased glutathione levels and Bcl-2 expression were observed in IECs of these rats, whereas food restriction did not affect these parameters.

CONCLUSIONS

Protein restriction increased only IEC apoptosis, whereas vitamin restriction also affected the structure and function of villi. Modulation of the pathway mediated by mitochondria through increased oxidative stress appears to be the probable mechanism underlying this effect.

[The results of application of magnesium-bearing medications and different load doses of vitamins B1 and B2 in volunteers]

Presently is no consensus of opinion of the size of human optimal daily allowance as for thiamine and riboflavin, so for magnesium, what their content in polyvitamin and mineral preparations testify to. The study was conducted in 60 volunteers, who once took oral dosing of magnesium -bearing preparation "Magnerot" (500 mg of magnesium orotat converting to Mg2+ 32,8 Mg) and "Centrum" (100 mg of magnesium oxide converting to Mg2+ - 60,3 Vg) or vitamins B1 and B2 in 10, 20 and 30 mg doses. The received data testify that during the application of both of these preparations, equal concentration of this element takes place, though in case of magnesium oxide it happens later. As for the used vitamin B1 and B2 doses, it is determined that 10 mg is the optimal dose for treating their hypoavitaminosis.

A semimechanistic-physiologic population pharmacokinetic/pharmacodynamic model for neutropenia following pemetrexed therapy

PURPOSE

The objectives of these analyses were to (1) develop a semimechanistic-physiologic population pharmacokinetic/pharmacodynamic (PK/PD) model to describe neutropenic response to pemetrexed and to (2) identify influential covariates with respect to pharmacodynamic response.

PATIENTS AND METHODS

Data from 279 patients who received 1,136 treatment cycles without folic acid or vitamin B12 supplementation during participation in one of eight phase II cancer trials were available for analysis. Starting doses were 500 or 600 mg pemetrexed per m2 body surface area (BSA), administered as 10-min intravenous infusions every 21 days (1 cycle). The primary analyses included 105 patients (279 cycles) for which selected covariates-including vitamin deficiency marker data (i.e., homocysteine, cystathionine, methylmalonic acid, and methylcitrate [I, II, and total] plasma concentrations)-were available. Classical statistical multivariate regression analyses and a semimechanistic-physiologic population PK/PD model were used to evaluate neutropenic response to single-agent pemetrexed administration.

RESULTS

The timecourse of neutropenia following single-agent pemetrexed administration was adequately described by a semimechanistic-physiologic model. Population estimates for system-based model parameters (i.e., baseline neutrophil count, mean transit time, and the feedback parameter), which mathematically represent current understanding of the process and physiology of hematopoiesis, were consistent with previously reported values. The population PK/PD model included homocysteine, cystathionine, albumin, total protein, and BSA as covariates relative to neutropenic response.

CONCLUSION

These results support the programmatic decision to introduce folic acid and vitamin B12 supplementation during pemetrexed clinical development as a means of normalizing patient homocysteine levels, thereby managing the risk of severe neutropenia secondary to pemetrexed administration. The current results also suggest that the addition of vitamin B6 supplementation to normalize patient cystathionine levels may further decrease the incidence of grade 4 neutropenia following pemetrexed administration. The results also suggest the use of folic acid as a means of lessening hematologic toxicity following administration of cytotoxic agents other than antifolates.

Prevalence and mechanisms of hyperhomocysteinemia in chronic alcoholics

BACKGROUND

Homocysteine (Hcy) is formed as an intermediary in methionine metabolism. Impairment of Hcy remethylation or transulfuration leads to hyperhomocysteinemia, which is considered as a risk factor for atherosclerotic vascular disease and stroke in chronic alcoholics. The aim of the study was to investigate the prevalence of hyperhomocysteinemia in chronic alcoholics and the influence of alcohol consumption, vitamin deficiencies and liver damage on the plasma levels of Hcy.

METHODS

228 chronic alcoholic patients consecutively admitted for detoxication, classified according to clinical and biochemical data in normal liver (n = 117), and in mild to moderate liver disease (n = 111), and 49 healthy controls were studied. Blood levels of Hcy, vitamin B6, vitamin B12 and folate were measured.

RESULTS

Plasma Hcy was significantly higher in chronic alcoholics than in controls (9.66 +/- 8.1 vs. 6.93 +/- 2.33 mumol/liter, p < 0.025). Furthermore, plasma Hcy levels were significantly higher in chronic alcoholics with liver injury (12.17 +/- 10.14 mumol/liter) than in those with normal liver and in controls (p < 0.001). The prevalence of hyperhomocysteinemia was also significantly higher in alcoholics with liver damage than in those with normal liver and in controls (29.7%, 5.1%, and 2%, respectively, p < 0.001). Serum folate values were lower in chronic alcoholics than in controls (4.7 +/- 2.6 vs. 7.6 +/- 2.4 nmol/liter, p < 0.001). The lowest values of folate were found in alcoholics with liver disease, especially in those with hyperhomocysteinemia, with a negative correlation between the two parameters.

CONCLUSIONS

Moderate hyperhomocysteinemia is common in chronic alcoholics, mainly in those with liver damage, suggesting that, although folate deficiencies may have a contributory role, liver impairment, through changes in methionine metabolism, is the most important mechanism for the elevated plasma Hcy found in these patients.

Mild neonatal hypoxia exacerbates the effects of vitamin-deficient diet on homocysteine metabolism in rats

Elevated plasma homocysteine has been linked to pregnancy complications and developmental diseases. Whereas hyperhomocysteinemia is frequently observed in populations at risk of malnutrition, hypoxia may alter the remethylation of homocysteine in hepatocytes. We aimed to investigate the combined influences of early deficiency in nutritional determinants of hyperhomocysteinemia and of neonatal hypoxia on homocysteine metabolic pathways in developing rats. Dams were fed a standard diet or a diet deficient in vitamins B12, B2, folate, month, and choline from 1 mo before pregnancy until weaning of the offspring. The pups were divided into four treatment groups corresponding to "no hypoxia/standard diet," "hypoxia (100% N2 for 5 min at postnatal d 1)/standard diet," "no hypoxia/deficiency," and "hypoxia/deficiency," and homocysteine metabolism was analyzed in their liver at postnatal d 21. Hypoxia increased plasma homocysteine in deficient pups (21.2 +/- 1.6 versus 13.3 +/- 1.2 microM, p < 0.05). Whereas mRNA levels of cystathionine beta-synthase remained unaltered, deficiency reduced the enzyme activity (48.7 +/- 2.9 versus 83.6 +/- 6.3 nmol/h/mg, p < 0.01), an effect potentiated by hypoxia (29.4 +/- 4.7 nmol/h/mg, p < 0.05). The decrease in methylene-tetrahydrofolate reductase activity measured in deficient pups was attenuated by hypoxia (p < 0.05), and methionine-adenosyltransferase activity was slightly reduced only in the "hypoxia/deficiency" group (p < 0.05). Finally, hypoxia enhanced the deficiency-induced drop of the S-adenosylmethionine/S-adenosylhomocysteine ratio, which is known to influence DNA methylation and gene expression. In conclusion, neonatal hypoxia may increase homocysteinemia mainly by decreasing homocysteine transsulfuration in developing rats under methyl-deficient regimen. It could therefore potentiate the well-known adverse effects of hyperhomocysteinemia.

[Vitamin status in human noninfectious chronic diseases]

The data on vitamin sufficiency of adults and children suffering from chronic sickness and vitamin content in mostly common hospital diets has been submitted. Polyhypovitaminosis (combined insufficiency with several vitamins) takes place irrespective of season, age and place of residence. Deficit of B group vitamins and carotenoids has been observed more frequently. All hospital diets contain inadequate level of carotenoids, strongly reduced diets are deficiently in all vitamins. Any way of vitaminization (vitamins administration, including of vitamin-enriched food products in the ration) leads to the decrease of polyhypovitaminosis frequency, to the increase of the part of people adequately supplied with all vitamins and simultaneous improvement of patients clinic status.

Interaction between vitamins C and E affects their tissue concentrations, growth, lipid oxidation, and deficiency symptoms in yellow perch (Perca flavescens)

We have conducted studies with juvenile yellow perch (Perca flavescens) over a period of 20 weeks to address the question of the interaction between water- and lipid-soluble antioxidant vitamins. Fish (2.25+/-0.14 g) were divided into twelve groups, and triplicate groups were fed one of four casein-based, semi-purified diets formulated to contain low or high vitamin E levels of either 5 or 160 mg/kg without or with vitamin C supplementation (250 mg/kg). Diets were designated as -C-E, -C+E, +C-E, or +C+E, respectively. The fish fed the +C+E diet showed significantly higher weight gain, feed intake, and feed efficiency than the groups fed vitamin C-deficient diets. Total ascorbate concentrations of liver were significantly higher in fish fed vitamin C-supplemented diets than in fish fed the vitamin C-deficient diet after 16 and 20 weeks. The liver alpha-tocopherol concentrations were increased by supplemental vitamin C in vitamin E-deficient dietary groups which indicates a sparing or regenerating effect of vitamin C on vitamin E. Fish fed vitamin C-deficient diets (-C-E and -C+E) exhibited severe deficiency symptoms, such as scoliosis, lens cataracts, anorexia, and haemorrhages. The cumulative mortality was significantly higher in the -C-E groups. The thiobarbituric acid-reactive substances value was significantly higher in blood plasma of fish fed a diet unsupplemented with both vitamins. The findings in the present study with yellow perch support the hypothesis that vitamin C regenerates and/or spares vitamin E in vivo.

Effect of long-term dietary manipulation on the aggregation of rat lens crystallins: role of alpha-crystallin chaperone function

PURPOSE

To investigate the effect of food, protein, and vitamin restriction on the susceptibility of lens crystallins to aggregation and chaperone activity of alpha-crystallin.

METHODS

Thirty day old Wistar/NIN rats were maintained on regular rodent diet (C), 50% food restriction (FR), 75% protein restriction (PR), and 50% vitamin restriction (VR) diet for 20 weeks. At the end, alpha-, beta-, and gamma-crystallins were isolated from the lenses of these animals and subjected to in vitro aggregation induced by oxidation, UV irradiation and heat. Aggregation and chaperone activity was assessed by light scattering methods.

RESULTS

Dietary restriction has been shown to extend the mean and maximum life span and retard age-related diseases, including cataract. In this study, we demonstrate that while beta- and gamma-crystallins isolated from FR and PR groups were less susceptible to in vitro induced aggregation, beta- and gamma-crystallins from the VR group were more susceptible, compared to controls. Alpha-crystallin from any of the groups did not shown a considerable amount of aggregation. On the other hand, the chaperone activity of alpha-crystallin from FR and PR groups was not significantly different from controls. However, alpha-crystallin from the VR group demonstrated substantially higher chaperone activity than controls.

CONCLUSIONS

These results indicate that while food and protein restriction appear to lower the susceptibility of beta- and gamma-crystallins towards aggregation, vitamin restriction tends to increase the aggregation. Chaperone activity of alpha-crystallin is affected (improved) by only vitamin restriction.

Nutritional factors and Alzheimer's disease

Nutritional factors are integrally linked with Alzheimer's disease (AD). Although AD patients have no changes in energy metabolism, fluctuations in weight are fairly common. The potential role of vitamin B(12) and folate, with the production of hyperhomocysteinemia, in the pathophysiology of AD is explored. The role of free-radical damage in AD is discussed. It is stressed that alterations in dietary lipids may play an important role in cognitive defects in AD secondary to their effects on neuronal membrane lipids. More research is needed on the role of nutrition in the ongoing development of cognitive changes in AD.

Nutrition and cognitive impairment in the elderly

As the number of older people is growing rapidly worldwide and the fact that elderly people are also apparently living longer, dementia, the most common cause of cognitive impairment is getting to be a greater public health problem. Nutrition plays a role in the ageing process, but there is still a lack of knowledge about nutrition-related risk factors in cognitive impairment. Research in this area has been intensive during the last decade, and results indicate that subclinical deficiency in essential nutrients (antioxidants such as vitamins C, E and beta-carotene, vitamin B(12), vitamin B(6), folate) and nutrition-related disorders, as hypercholesterolaemia, hypertriacylglycerolaemia, hypertension, and diabetes could be some of the nutrition-related risk factors, which can be present for a long time before cognitive impairment becomes evident. Large-scale clinical trials in high-risk populations are needed to determine whether lowering blood homocysteine levels reduces the risk of cognitive impairment and may delay the clinical onset of dementia and perhaps of Alzheimer's disease. A curative treatment of cognitive impairment, especially Alzheimer's disease, is currently impossible. Actual drug therapy, if started early enough, may slow down the progression of the disease. Longitudinal studies are required in order to establish the possible link of nutrient intake--nutritional status with cognitive impairment, and if it is possible, in fact, to inhibit or delay the onset of dementia.

Pyridoxal phosphate de-activation by pyrroline-5-carboxylic acid. Increased risk of vitamin B6 deficiency and seizures in hyperprolinemia type II

We previously identified vitamin B6 deficiency in a child presenting with seizures whose primary diagnosis was the inherited disorder hyperprolinemia type II. This is an unrecognized association, which was not explained by diet or medication. We hypothesized that pyridoxal phosphate (vitamin B6 coenzyme) was de-activated by L-Delta(1)-pyrroline-5-carboxylic acid, the major intermediate that accumulates endogenously in hyperprolinemia type II. The proposed interaction has now been investigated in vitro with high resolution 1H nuclear magnetic resonance spectroscopy and mass spectrometry at a pH of 7.4 and temperature of 310 K. Three novel adducts were identified. These were the result of a Claisen condensation (or Knoevenagel type of reaction) of the activated C-4 carbon of the pyrroline ring with the aldehyde carbon of pyridoxal phosphate. The structures of the adducts were confirmed by a combination of high performance liquid chromatography, nuclear magnetic resonance, and mass spectrometry. This interaction has not been reported before. From preliminary observations, pyrroline-5-carboxylic acid also condenses with other aromatic and aliphatic aldehydes and ketones, and this may be a previously unsuspected generic addition reaction. Pyrroline-5-carboxylic acid is thus found to be a unique endogenous vitamin antagonist. Vitamin B6 de-activation may contribute to seizures in hyperprolinemia type II, which are so far unexplained, but they may be preventable with long term vitamin B6 supplementation.

ALCOHOL: its metabolism and interaction with nutrients

In the past, alcoholic liver disease was attributed exclusively to dietary deficiencies, but experimental and judicious clinical studies have now established alcohol's hepatotoxicity. Despite an adequate diet, it can contribute to the entire spectrum of liver diseases, mainly by generating oxidative stress through its microsomal metabolism via cytochrome P4502E1 (CYP2E1). It also interferes with nutrient activation, resulting in changes in nutritional requirements. This is exemplified by methionine, one of the essential amino acids for humans, which needs to be activated to S-adenosylmethionine (SAMe), a process impaired by liver disease. Thus, SAMe rather than methionine is the compound that must be supplemented in the presence of significant liver disease. In baboons, SAMe attenuated mitochondrial lesions and replenished glutathione; it also significantly reduced mortality in patients with Child A or B cirrhosis. Similarly, decreased phosphatidylethanolamine methyltransferase activity is associated with alcoholic liver disease, resulting in phosphatidylcholine depletion and serious consequences for the integrity of membranes. This can be offset by polyenylphosphatidylcholine (PPC), a mixture of polyunsaturated phosphatidylcholines comprising dilinoleoylphosphatidylcholine (DLPC), which has high bioavailability. PPC (and DLPC) opposes major toxic effects of alcohol, with down-regulation of CYP2E1 and reduction of oxidative stress, deactivation of hepatic stellate cells, and increased collagenase activity, which in baboons, results in prevention of ethanol-induced septal fibrosis and cirrhosis. Corresponding clinical trials are ongoing.

Micronutrients in the severely-injured patient

The trace element and vitamin requirements of severely-ill injured patients depend on a complex interaction of the status of the patient at the time of admission, ongoing losses and the potential benefit of supplying large amounts of individual micronutrients. Characteristic clinical deficiency states are now uncommon, but subclinical deficiency is of growing concern. The main effects of subclinical deficiency are: (1) an altered balance of reactive oxygen species and antioxidants, leading to oxidative damage of polyunsaturated fatty acids and nucleic acids, and possibly to increased activation of the transcription factor nuclear factor-kappaB, with increased production of pro-inflammatory cytokines: (2) impaired immune function with increased likelihood of infectious complications. Laboratory tests to optimize intake in such critically-ill patients lack sensitivity and specificity, this situation being made worse as a result of the acute-phase response. Recent studies have indicated the clinical benefit of providing large amounts of certain micronutrients in burned and head-injured patients. Further clinical studies are now required to define optimal levels of provision in different disease states, with a particular emphasis on markers of tissue function and clinical outcome.

Mechanisms of vitamin deficiency in chronic alcohol misusers and the development of the Wernicke-Korsakoff syndrome

The classic signs of vitamin deficiency only occur in states of extreme depletion and are unreliable indicators for early treatment or prophylaxis of alcoholic patients at risk. Post-mortem findings demonstrate that thiamine (vitamin B1) deficiency sufficient to cause irreversible brain damage is not diagnosed ante mortem in 80-90% of these patients. The causes of vitamin deficiency are reviewed with special attention to the inhibition of oral thiamine hydrochloride absorption in man caused by malnutrition present in alcoholic patients or by the direct effects of ethanol on intestinal transport. As the condition of the patient misusing alcohol progresses, damage to brain, liver, gastrointestinal tract, and pancreas continue (with other factors discussed) to further compromise the patient. Decreased intake, malabsorption, reduced storage, and impaired utilization further reduce the chances of unaided recovery. Failure of large oral doses of thiamine hydrochloride to provide an effective treatment for Wernicke's encephalopathy emphasizes the need for adequate and rapid replacement of depleted brain thiamine levels by repeated parenteral therapy in adequate doses.

Drugs-nutrient interactions: a potential problem during adolescence

The concept of drug-nutrient interactions is not new, but it has only recently gained currency in medicine. Although the elderly are normally considered to be at particular risk, other groups may also be at risk: infants, adolescents, pregnant women, alcohol and tobacco users, etc. In infants and adolescents there are several factors that may influence the possible interactions: firstly, nutrient needs are usually higher, mainly micronutrients; systems for detoxification of anutrients are not complete; the tendency to restricted diets (especially girls) that are unable to cover the actual recommended intakes for a number of micronutrients (i.e. vitamins); and the dangerous increase in alcohol consumption either in males or females. Administration of drugs in population with adequate vitamin intake is usually not a problem, but administration of drugs in those with borderline intake of vitamins or in patients with low nutritional status can result in symptomatic vitamin deficiency states. The groups at risk of poor vitamin status are smokers (a high proportion of adolescents are active smokers); dieters (skipping meals and dieting to lose weight frequently compromise micronutrient intake, and it should be considered that it is extremely difficult to meet all the requirements at intakes of less than 1,200 calories per day), oral contraceptive users, and pregnant and lactating women, excessive alcohol users, etc. The chapter also focuses on the case of folate: rapidly dividing tissues during the adolescent growth spurt increase requirements for folate. Because of this increased need, folate status appears to be of concern during the age of this rapid growth. A variety of drugs are known to interfere with vitamin utilization by blocking or altering transformation of the vitamin to its metabolically active form. Serum folate levels are known to be low in a high percentage of patients with rheumatoid arthritis, suggesting that aspirin alters the transport of folate by competition for binding sites on serum proteins. Methotrexate, a drug commonly used at low doses for the treatment of psoriasis, rheumatoid arthritis and certain liver disorders, limits the availability of methyl groups derived from one-carbon metabolism by inhibiting competitively a key enzyme in the intracellular folate metabolism. In humans, the antiepileptic drug valproic acid (VPA) is associated with two major adverse effects: teratogenicity and folate deficiency. The mechanisms by which VPA exerts the teratogenic or antifolate effect remain unclear, but an alteration in the methionine cycle is the strongest hypothesis proposed.

Genetic causes of rickets

Dietary deficiency of vitamin D, genetic disorders of its bioactivation to 1,25-dihydroxyvitamin D [1,25(OH)2D], or disorders of vitamin D action can cause rickets. The rate-limiting, hormonally-regulated, biologically activating step in the synthesis of 1,25(OH)2D is the 1 alpha-hydroxylation of 25-hydroxyvitamin D, which occurs in kidney and other tissues and is mediated by a mitochondrial cytochrome P450 enzyme, P450c1 alpha. After many years of effort, the cDNA and gene for this enzyme were cloned in late 1997. Mutations in the P450c1 alpha gene, located on chromosome 12, cause 1 alpha-hydroxylase deficiency, also known as vitamin D-dependent rickets type I, an autosomal recessive disease characterized by rickets and impaired growth due to failure of renal synthesis of 1,25(OH)2D. X-linked hypophosphatemic rickets, a dominantly inherited disease, is caused by mutations in the PHEX gene, whose function in regulating renal phosphate and vitamin D metabolism remains to be elucidated.

Micronutrients and the pathogenesis of human immunodeficiency virus infection

Micronutrient deficiencies may be common during human immunodeficiency virus (HIV) infection. Insufficient dietary intake, malabsorption, diarrhoea, and impaired storage and altered metabolism of micronutrients can contribute to the development of micronutrient deficiencies. Low plasma or serum levels of vitamins A, E, B6, B12 and C, carotenoids, Se, and Zn are common in many HIV-infected populations. Micronutrient deficiencies may contribute to the pathogenesis of HIV infection through increased oxidative stress and compromised immunity. Low levels or intakes of micronutrients such as vitamins A, E, B6 and B12, Zn and Se have been associated with adverse clinical outcomes during HIV infection, and new studies are emerging which suggest that micronutrient supplementation may help reduce morbidity and mortality during HIV infection.

Diagnosis and detection of vitamin deficiencies

Vitamin deficiencies can be detected in several ways, none of which is entirely unambiguous. Evidence of several types is, therefore, required. For instance, it is rare for clinical signs to result from a single cause, except in controlled experiments. Natural diets are rarely deficient in only a single nutrient, and individual requirements vary considerably. Biochemical and functional status indices can help bridge the gap between inadequate diet and resulting pathology. Some indices are very specific for individual vitamins; others, although only semi-specific, are useful if closely linked to tissue malfunction and hence to pathology. Ideally, biochemical indices should separate severe deficiency, mild subclinical deficiency, normal status and overload toxicity. Vitamin concentrations in plasma, serum, red cells, urine, and other accessible tissues have been used, and metabolic products of vitamin-dependent metabolic pathways have been exploited. However, many of the assays are difficult to perform and interpret, and are limited to few laboratories, world-wide. There is a need for simpler and more 'portable' tests, for routine laboratories and for the medical profession.

Lipids and lipid-activated vitamins in chronic cholestatic diseases

Primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune cholangiopathy are cholestatic liver diseases of unknown cause. Destruction of small to medium bile ducts (in primary biliary cirrhosis and autoimmune cholangiopathy) and large bile ducts (in primary sclerosing cholangitis) leads to progressive cholestasis, liver failure and end-stage liver disease. A variety of abnormalities in lipid metabolism have been described in primary biliary cirrhosis, and range from alterations in serum lipid levels and lipoprotein subsets to deranged metabolism of cholesterol. Progressive cholestasis and, consequently, decreased small intestinal bile acid concentrations in these cholestatic liver disease can also lead to impaired absorption of fats and fat-soluble vitamins, resulting in steatorrhea and deficiencies in vitamins A, D, E, and K. This article focuses on abnormalities in lipid metabolism in primary biliary cirrhosis and primary sclerosing cholangitis, and on lipid-activated vitamin deficiencies in these disorders.

Vitamin and trace mineral withdrawal effects on broiler breast tissue riboflavin and thiamin content

An investigation was carried out to determine whether a Day 28 to 49 dietary vitamin, trace mineral, and vitamin plus trace mineral premix withdrawal would impact Pectoralis major thiamin or riboflavin concentration in chicks reared under thermoneutral (24 C) and heat-stressed (24 to 35 C) conditions. No significant (P > 0.1) environment by nutrient withdrawal interactions were detected. Heat stress and vitamin withdrawal reduced (P < 0.05) P major thiamin and riboflavin concentration. In contrast, trace mineral withdrawal failed (P> 0.1) to impact either vitamin. In conclusion, results from this study suggest that a 21-d vitamin withdrawal and heat stress exposure have the potential to reduce muscle riboflavin and thiamin concentration.

[The transcerebral use of an impulse current in experimental alimentary hypercholesterolemia]

25 rats with alimentary hypercholesterolemia induced by diet rich in cholesterol and mercazoline were exposed to frontomastoid impulse current (1000 Hz, 0.75 mA). The treatment promoted normalization of lipid and protein metabolism in the myocardium and liver, of thyroid hormones and antiproteinase activity of the serum. Positive trends were noted in the activity of thymocyte nuclei and lipid peroxidation in the cerebral cortex.

[Scurvy, a serious and rare form of avitaminosis, easily diagnosed and treated. Presentation of a case]

We report a 66 years-old man case that was admitted with abdominal wall hemorrhagic swelling ecchymosis on inferior extremities and perifollicular purpura with hyperkeratosis of the follicles, which gives it an appearance of palpable purpura, together with gingival hemorrhage and moderate anemia. He was a well-nourished sick man but who made a peculiar diet, practically free from fruit and vegetables which developed a pure and serious form of scurvy. We report this case because we consider that the features which appear are illustrative to provide the immediate clinical diagnosis of this uncommon disease, potentially mortal, but easy to diagnose, if we think about it in the adequate clinical contexts, and which it is quickly curable with the administration of ascorbic acid.

Effects of vitamin B12, folate, and vitamin B6 supplements in elderly people with normal serum vitamin concentrations

In a prospective, multicentre, double-blind controlled study, the effect of an intramuscular vitamin supplement containing 1 mg vitamin B12, 1.1 mg folate, and 5 mg vitamin B6 on serum concentrations of methylmalonic acid (MMA), homocysteine (HCYS), 2-methylcitric acid (2-MCA), and cystathionine (CYSTA) was compared with that of placebo in 175 elderly subjects living at home and 110 in hospital. Vitamin supplement and placebo were administered eight times over a 3-week period. Vitamin supplement but not placebo significantly reduced all four metabolite concentrations at the end of the study in both study groups. The maximum effects of treatment were usually seen within 5-12 days. Initially elevated metabolite concentrations returned to normal in a higher proportion of the vitamin than of the placebo group: 92% vs 20% for HYCS; 82% vs 20% for MMA; 62% vs 25% for 2-MCA; and 42% vs 25% for CYSTA. The response rate to vitamin supplements supports the notion that metabolic evidence of vitamin deficiency is common in the elderly, even in the presence of normal serum vitamin levels. Metabolite assays permit identification of elderly subjects who may benefit from vitamin supplements.

[The vitamin and trace element status of the personnel of the Chernobyl Atomic Electric Power Station and of preschool children in the city of Slavutich]

Supply of the Chernobyl NPP staff and Slavutich children with vitamins and minerals has been examined in spring 1992. From 43 to 100% of people have moderate deficiency of vitamin C, B1, B2, B6 and folic acid, 6-61%--deep deficiency of these nutrients. Most of the people have insufficient supply with vitamins in the form of polyhypovitaminosis, i.e. combined deficiency of ascorbic acid and of 2 or 3 vitamins of the B group. Deficiency of 2 vitamins was found in 20% of adults of 3 vitamins in 37%, of 4 vitamins in 29% and of 1 vitamin in 10% of adults. Only 4% of examined adults are sufficiently supplied with all vitamins and none of children. Deficiency of 1 vitamin was found in 11% of children, of 2 vitamins in 15%, of 3 vitamins in 17%, of 4 vitamins in 35%, of 5 vitamins in 20% and of 6 vitamins in 2% of children. Supply of children with all vitamins has been improved when they received combined vitamin-mineral preparation "Duovit" for one month. Universal prophylactic vitaminization by means of administration of ascorbic acid and polyvitamin preparations in doses corresponding to the daily physiological requirement should be recommended as the most reliable, effective and economical measure aimed to improve supply of the population with vitamins.

[Importance of and need for vitamins in old age]

Vitamins may modulate primary as well as secondary processes of aging. On the other hand, vitamin metabolism itself may be modified by the process of aging or by various chronic diseases connected with aging. On the basis of these multiple interactions the question arises whether the demand for individual vitamins is altered as a consequence of aging. Age-dependent metabolic changes may alter the need for individual vitamins. This is the case for vitamin D, vitamin B6, Riboflavine, and in special subpopulations for vitamin B12. The most important source for a sufficient supply of vitamins is an adequate nutrition. Thus, besides the aforementioned vitamins, insufficient alimentary intake with food plays the most important role in vitamin deficiency in the elderly. Due to age-specific alterations of the vitamin-A metabolism, toxicity of vitamin-A plays a more important role than vitamin-A deficiency. The vitamins A and D as well as vitamin C are discussed in detail.

[The evaluation of the efficacy of a 6-month vitaminization of schoolchildren in grades 1 to 8 in the city of Baku]

Investigations were conducted in 110 schoolchildren aged 7-10 and 11-14 years. They had received insufficiently balanced traditional nutrition deficient in animal proteins, vegetable oils, calcium, and, especially, in vitamins. Excretion of ascorbic acid, thiamine, riboflavine, N1-HA was decreased as compared to the lower standard limits 3.5-1.9 times in 85-90% of schoolchildren aged 7-14 years, microsymptoms of vitamin deficiency (including polyvitamin deficiency) were noted in 33-53% of the children. Administration of varying doses of "Undevitum" (0.5, 1 and 1.5 dragees/day) has shown that for normalization of vitamin status, decreasing morbidity rate and improvement of their mental capacity, the schoolchildren of 1-4 forms should receive 1 dragee and those of 5-8 forms--1.5 dragee of "Undevitum"/day as an optimum dose.

[The vitamin content of the blood and urine in alcoholism patients]

It was established that chronic alcohol intoxication is accompanied by development of multivitamin insufficiency. In the initial stage of the disease the patients showed only biochemical signs and at later stages also clinical signs of hypovitaminosis.