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PubMed1990

Vitamin A deficiency in pre-school age Congolese children during malarial attacks. Part 2: Impact of parasitic disease on vitamin A status.

The vitamin A status of 454 pre-school age Congolese children was evaluated by the impression cytology method with transfer (ICT) and by the determination of plasma retinol. During malarial attacks, the vitamin A status is abnormal (deficient or marginal) in 40.8% of the children according to the ICT test and in 37.5% of the children who have plasma levels of retinol lower than 10 micrograms/dl. The mean concentration of plasma retinol in patients during malarial attacks (14.8 +/- 9.5 micrograms/dl) is significantly lower than the values found in other subjects (31.5 +/- 14.3 micrograms/dl) (p less than 0.001). A significant correlation was established between the results of the ICT test and two biochemical parameters (retinol, transthyretin). We conclude that there is a significant relationship between vitamin A deficiency and a malarial attack.

Child↗

PubMed1985

Improved radioimmunoassay for vitamin D and its use in assessing vitamin D status.

We describe a faster, more-sensitive radioimmunoassay for vitamin D in plasma. Antibodies were generated in rabbits immunized with a new vitamin D analog, the 23,24,25,26,27-pentanor-C(22)-carboxylic acid of vitamin D, coupled directly with bovine serum albumin. After several months, Rivanol-treated sera from the rabbits contained high-titer antibodies, as determined by their abilities to bind 25-hydroxy-[3H]cholecalciferol. The antibody, used at a 1:15 000 final dilution, cross reacted equally with all cholecalciferol and ergocalciferol metabolites tested except 1,25-dihydroxycalciferol metabolites and the parent calciferols. 25-Hydroxycalciferol and similar forms were efficiently extracted from plasma or serum with acetonitrile. We separated bound from free 25-hydroxy-[3H]cholecalciferol by using a second antibody: goat antiserum to rabbit serum. The detection limit of the assay was 3.0 pg of 25-hydroxycholecalciferol and its equivalents per tube; thus only 1 microL of plasma is needed per assay tube. Results compared well with those from a liquid-chromatographic procedure involving specific ultraviolet detection of 25-hydroxycalciferol in plasma.

Animals↗

PubMedDate not supplied

[Effect of different forms of vitamin A and its combination with vitamin E on the peroxidation of lipids].

Effect of vitamins A and E derivatives on Fe-ascorbate dependent peroxidation was studied by means of thiobarbituric acid test in liposomes prepared from egg lecithin. Retinol, incorporated into liposomes at concentration less than 0.1 mol%, increases the lecithin oxidation, retinyl palmitate was less active and alpha-tocopherol inhibited the reaction. Synergistic effect of alpha-tocopherol and retinol was observed. After simultaneous administration of retinol and alpha-tocopherol into liposomes, vitamin A did not accelerate the lecithin oxidation but increased distinctly the inhibitory effect of alpha-tocopherol. This interaction did not occur between retinol and alpha-tocopherol acetate as well as between m-retinyl acetate and alpha-tocopherol. The data obtained suggest that vitamins A and E affect the lipid peroxidation not only via direct participation in free radical oxidation but also due to transformations of biological membranes structure.

Diterpenes↗

PubMed1995

[The vitamin allowance of the adult population of the Russian Federation and its changes in 1983-1993. 1. Vitamins C, E, A and carotene].

The investigations carried out in 1983-1993 showed increasing of insufficiency of vitamin C and carotene in population of almost all investigated areas of Russian Federation. Insufficiency of vitamin C was found in 70-95%, pronounced deficit in 45-70% of adults. Deficiency of carotene was was detected in 30-90% of adults. Insufficiency of these nutrients is unfavourable long condition detected not only during spring but also in summer in different occupational groups of population. Vitamins A and E nutritional status of different groups of population are good enough in all seasons.

Adolescent↗

PubMed1995

Vitamin A deficiency in non-vitamin-supplemented patients with AIDS: a cross-sectional study.

The prevalence of vitamin A deficiency and its association with dietary retinol intake in patients with AIDS was assessed in a cross-sectional study. Sixty eligible patients with AIDS provided serum samples that were analyzed for retinol content. Exclusion criteria included current use of vitamin supplements (57% of the 140 willing to participate) and pregnancy (none). Past dietary intake was determined using a standardized food intake frequency questionnaire. The prevalence of hyporetinemia was 22%. This was a 241-fold greater prevalence than that of a representative sample of the U.S. population, after adjusting for age and sex. There was a positive association between serum retinol status and dietary intake, but 27% of those with adequate intake had serum retinol levels below the normal range. These findings suggest that regardless of intake, patients with AIDS may represent a population at considerable risk of vitamin A deficiency.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Seasonal variation in vitamin D, vitamin D-binding protein, and dehydroepiandrosterone: risk of prostate cancer in black and white men.

Our previous study provided evidence that higher serum levels of the active form of vitamin D, 1,25-dihydroxyvitamin D (1, 25-D), might possibly slow the progression of subclinical to clinically significant prostate cancer in both black and white men, especially after age 57. This paper extends the prior study by contrasting seasonal variation in 1,25-D and its precursor, 25-hydroxyvitamin D (25-D), in case and control subjects. In addition, the risk of prostate cancer is related to serum levels of vitamin D-binding protein (VDBP) and total dehydroepiandrosterone and to polymorphic variation in VDBP. The expected elevated summer levels of 25-D were seen in case and control subjects and, as expected, 1,25-D did not vary throughout the year in the control subjects. Unexpectedly, lower case levels of 1,25-D were limited largely to the summer months (P = 0.01) in both black and white cases and to cases greater than or equal to the median age of 57 years. Levels of VDBP and dehydroepiandrosterone and the frequencies of VDBP polymorphisms were similar in case and control subjects, although striking differences were seen in allelic frequencies in black and white men. These observations provide additional evidence that vitamin D metabolism may impact the risk of prostate cancer.

Adult↗

PubMed1996

Anthropometric, vitamin A, iron and immunisation coverage status in children aged 6-71 months in South Africa, 1994. South African Vitamin A Consultative Group (SAVACG).

OBJECTIVE AND DESIGN: To establish the anthropometric, vitamin A, iron and immunisation coverage status of children 6-71 months of age in South Africa by means of a national survey. SETTING: South Africa. PARTICIPANTS: The study population consisted of all children in the country aged 6-71 months. A total of 18,219 households (19,003 families) was selected on the basis of a national probability sample with disproportionate stratification by province. OUTCOME MEASURES: Serum retinol, serum ferritin, haemoglobin, mean corpuscular volume, weight, height and immunisation status. RESULTS: According to international criteria, the national prevalence of marginal vitamin A status found in the survey identifies the country as having a serious public health problem of vitamin A deficiency. Stunting is a major problem in the country and is more prevalent in rural than in urban communities. In terms of anaemia and poor iron status, children in the 6-23-month age group were the most severely affected. A trend for increased immunisation coverage over the past 5 years was evident in every dose and in the percentage of fully immunised children.

Anemia↗

PubMed1996

Disappearance of skin lipofuscin storage and marked clinical improvement in adult onset coeliac disease and severe vitamin E deficiency after chronic vitamin E megatherapy.

A case of adult onset coeliac disease with IgA and severe vitamin E deficiencies, associated with cerebellar impairment and peripheral neuropathy, is described. Nerve conduction velocities, BAERs and SEP were altered. Brain nMR showed cortical atrophy mainly in the frontal and parietal regions. At ultrastructural examination, nerve biopsy showed a severe nerve fiber loss with presence of lipofuscin. Lipofuscin has been also found in skin and muscle biopsy. Duodenal biopsy showed villar atrophy with criptae hypoplasia. IgA, Apo A1 lipoprotein and cholesterol were decreased. Serum level of vitamin E was not detectable and its amount did not increase after an oral loading (2 g bolus). Parenteral vitamin E administration (900 mg/day) was able to normalize the plasma values only after 6 months of chronic administration of the drug in coincidence with a significant improvement of clinical and neurophysiological signs, and disappearance of lipofuscin storage in the skin biopsy.

Brain Diseases, Metabolic↗

PubMed1996

[The effect of vitamin A and beta-carotene on the vitamin E status, ejaculation parameters and health of boar used for insemination].

In this study consequences of vitamin A-supplementation to the vitamin E-status was investigated in the boar. Three groups of boars, each with 9 animals were fed over a period of seven month with 30000 I.E. Vit. A/kg concentrate (group A), 90 mg b-carotene + 1000 I.E. Vit. A/kg (group B) and 1000 I.E. Vit. A/kg (group C). Every boar was given 100 mg Vit. E/kg plus 50 ml soybean oil/kg to induce oxidative stress. After four month group C showed a higher amount of tocopherol in serum (p < 0.05). The amount of tocopherol in serum of the group B were exactly between group A and C. The amount of retinol in serum of the group C began to decrease after three month due to the high reserve capacity of the liver (p < 0.01). The retinyl ester in serum reflected the state of supply. 90 mg b-carotene led to an efficiency of 15000 I.E. Vit. A. The vitamin antagonism between Vit. A and Vit. E is not based on an antagonism of the intestinal resorption. There was no influence on the daily sperm production caused by different supplementations. The sperm quality was lowered in group C; the number of defective sperm increased (p < 0.001). The supplementation of soybean oil lead to an increase of the saturated fatty acids in the fatty acid pattern of the sperm cells. The increase of saturated fatty acids was the lowest in group C that showed the highest amount of tocopherol in serum.

Animal Feed↗

PubMed1991

Vitamin D analogs with low affinity for the vitamin D binding protein: enhanced in vitro and decreased in vivo activity.

The affinity of 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3] and analogs with side-chain modifications [MC 903 or calcipotriol, MC 1147 or 24,24-dihomo-1 alpha,25-(OH)2D3 and 1,25-(OH)2-16ene-23yne-D3] for the vitamin D receptor and the serum vitamin D binding protein (DBP) were compared. The affinity of MC 903 for the receptor from chick and rat duodenum or from human peripheral blood mononuclear cells or HL-60 cells varied between 60 and 100% relative to the affinity of 1,25-(OH)2D3. The relative affinity of 1,25-(OH)2-16ene-23yne-D3 and MC 1147 varied for the same receptors between 45-70 and 3.5-25%, respectively. The relative affinity of MC 903 for human DBP was 30-fold decreased, whereas the two other analogs did not bind to DBP at all even in more than 1000-fold excess. The in vitro biologic activity of 1 alpha,25-(OH)2D3 on phytohemagglutinin-stimulated normal human lymphocyte proliferation was markedly inhibited by the addition of physiologic amounts of DBP to the cell culture medium. No such inhibition was observed when MC 903 or 1147 was evaluated similarly. DBP therefore reversed the rank order of the in vitro potency of these analogs. Intramuscular injections for 10 consecutive days to vitamin D-deficient chicks demonstrated a greater than or equal to 100-fold lower biologic activity of MC 903, MC 1147, and 1,25-(OH)2-16ene-23yne-D3 compared to that of 1 alpha,25-(OH)2D3 as evaluated by serum calcium and osteocalcin concentrations, as well as by duodenal calbindin D28K and bone calcium content.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2002

Oxidative stress induced by phenylketonuria in the rat: Prevention by melatonin, vitamin E, and vitamin C.

Phenylketonuria (PKU) is an autosomal recessive disorder caused by a deficiency of the phenylalanine hydroxylation system and is characterized by a block in the conversion of phenylalanine (PHE) to tyrosine. We examined the effects of maternal hyperphenylalaninemia on the morphological and biochemical development of pup rat brain and cerebellum. In our model of PKU we evaluated a number of markers of oxidative stress such as Ehrlich adducts formation, lipid peroxidation, as well as the levels of reduced and oxidized glutathione, and the activities of the enzymes glutathione peroxidase and glutathione reductase. We also studied the expression of heme-oxigenase-1 and mitogen-activated protein kinase 1/2 (MAPK 1/2) as additional markers of oxidative stress. We demonstrate that PKU strongly increased most of the oxidative stress markers studied and induced significant morphological damage. We also showed that daily administration of melatonin (20 mg/kg BW), vitamin E (30 mg/kg BW), and vitamin C (30 mg/kg BW) until delivery prevented the oxidative biomolecular damage in the rat brain and cerebellum. Although no significant differences were observed among the antioxidants studied, it should be noted that the doses of melatonin were less than those for vitamins E and C. We conclude that PKU induces a clear state of oxidative stress that is somehow involved in the brain and body damage occurring in this inborn error. Moreover, melatonin and other antioxidants are capable of preventing completely the damage induced by PKU.

Animals↗

PubMed1992

Vitamin C and vitamin E--synergistic interactions in vivo?

The synergistic relationship between ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) in the inhibition of lipid peroxidation has been known for some time and is now well established in vitro systems. The possibility that ascorbic acid may also reduce tocopheroxyl radicals in vivo is a subject of some interest and speculation. Although not all experiments have failed to suggest a synergistic antioxidant interaction, recent data indicate that the postulated synergism between these vitamins might be relatively unimportant compared with other metabolic processes.

Animals↗

PubMed1985

Phosphate fluxes in isolated enterocytes from vitamin D replete and vitamin D deficient rats--early effects of calcitriol.

In the present work we studied rapid in vitro effects of calcitriol (1,25(OH)2 vitamin D3) on the intestinal transport of inorganic phosphate (Pi). Enterocytes from vitamin D replete (D+) as well as vitamin D depleted (D-) rats were isolated mechanically from the duodeno-jejunum. In this model, Pi uptake was a temperature and Na+-dependent phenomenon. The in vitro-addition of calcitriol (1 pM) resulted in a significant enhancement of initial Pi uptake rate by enterocytes from D+ (P less than 0.01) and D- (P less than 0.05) rats. This effect which was Na+-dependent, was observed within the time of 20 min, but not before. A similar effect on Pi uptake rates of D+ or D- enterocytes could be elicited by the in vitro addition of the methyl ester of cis-vaccinic acid (MCVA) which is thought to increase membrane fluidity by modifying the lipid composition of the cell membrane. The stimulatory effect of calcitriol on Pi uptake rate was blunted in the presence of the methyl ester of transvaccinic acid (MTVA) thought to decrease membrane fluidity. Enterocyte Pi efflux rate constant (oKPi) remained unchanged in the presence of calcitriol (1 pM). In conclusion, the study demonstrates a rapid in vitro effect of calcitriol on Pi uptake by isolated enterocytes from D+ and D- rats. It suggests, but does not prove, that the hormone may act via an action independent of genomic nuclear activation.

Animals↗

PubMed2005

Limited availability of nutritional vitamin D causing inappropriate treatment of vitamin D deficiency rickets with a response resembling pseudohypoparathyroidism type II in a Japanese patient.

Vitamin D deficiency rickets occasionally resembles pseudohypoparathyroidism type II (PHP type II) with respect to the response to exogenous PTH in the presence of hypocalcemia. We encountered a Japanese patient with stage 2 vitamin D deficiency rickets, who had increased urinary cAMP excretion and no response of urinary phosphate or N-acetyl-beta-D-glucosaminidase excretion to exogenous PTH under normocalcemic and normophosphatemic conditions, after treatment with 1,25(OH)2 vitamin D3. This case shows that it is possible for a response mimicking that of PHP type II to occur when the serum calcidiol level is low due to causes other than hypocalcemia and secondary hyperparathyroidism. When the serum calcidiol level is low, the appropriate treatment should be cholecalciferol or ergocalciferol. However, because neither is commercially available as a useful formulation in Japan, physicians are forced to inappropriately use calcitriol or analogs.

Calcifediol↗

PubMed2006

The effects of diazinon on lipid peroxidation and antioxidant enzymes in rat heart and ameliorating role of vitamin E and vitamin C.

Diazinon is one of the most widely used organophosphate insecticides (OPIs) in agriculture and public health programs. Reactive oxygen species (ROS) caused by OPIs may be involved in the toxicity of various pesticides. The aim of this study was to investigate how diazinon affects lipid peroxidation (LPO) and the antioxidant defense system in vivo and the possible ameliorating role of vitamins E and C. For this purpose, experiments were done to study the effects of DI on LPO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in adult rat heart. Experimental groups were: (1) control group, (2) diazinon treated (DI) group, (3) DI+vitamins E and C-treated (DI+Vit) group. The levels of malondialdehyde (MDA) and the activities of SOD and CAT increased significantly in the DI group compared with the control group. The activity of SOD and the levels of MDA decreased significantly in the DI+Vit group compared with the DI group. The differences between the DI+Vit and control groups according to the MDA levels and the activities of both SOD and CAT were statistically significant. These results suggest that treating rats with a single dose of diazinon increases LPO and some antioxidant enzyme activities in the rat myocardium and, in addition, that single-dose treatment with a combination of vitamins E and C after the administration of diazinon can reduce LPO caused by diazinon, though this treatment was not sufficiently effective to reduce the values to those in control group.

Animals↗

PubMed1990

Free radical-mediated chain oxidation of low density lipoprotein and its synergistic inhibition by vitamin E and vitamin C.

The oxidation of human low density lipoprotein (LDL) initiated by free radical initiator and its inhibition by vitamin E and water-soluble antioxidants have been studied. It was found that the kinetic chain length was considerably larger than 1, suggesting that LDL was oxidized by a free radical chain mechanism. Vitamin E acted as a lipophilic chain-breaking antioxidant. Water-soluble chain-breaking antioxidants such as ascorbic acid and uric acid suppressed the oxidation of LDL initiated by aqueous radicals but they could not scavenge lipophilic radicals within LDL to break the chain propagation. Ascorbic acid acted as a synergistic antioxidant in conjunction with vitamin E.

Ascorbic Acid↗

PubMed1984

Concentrations of vitamin E in various neuroanatomical regions and subcellular fractions, and the uptake of vitamin E by specific areas, of rat brain.

Vitamin E concentrations were determined by high-performance liquid chromatography in different anatomical regions of the brain from 3-month-old Fischer 344 rats. Gray matter from cerebellum and cervical spinal cord contained the lowest concentrations, while gray matter from the frontal cortex and thalamus had the highest concentrations of vitamin E. Radioactive alpha-tocopherol injected intravenously into the rat was readily taken up by brain although the level of uptake was very low compared with the liver. The ratios of brain-to-serum radioactivities ranged from 0.011 to 0.016 depending upon the brain region. Cerebellar gray matter is characterized by a low concentration of unlabeled alpha-tocopherol and a high level of uptake of radioactive alpha-tocopherol and thus is particularly active in the metabolism of vitamin E. Concentrations of unlabeled alpha-tocopherol were highest in microsomal and mitochondrial fractions and were the lowest in cytosol and nuclear fractions.

Animals↗

PubMed1975

Serial measurements of vitamin B-12 and vitamin B-12-binding capacity in marasmic kwashiorkor.

Vitamin B-12 and total vitamin B-12-binding capacity (TBBC) have been determined by a radio-saturation assay in the blood of a large group of patients suffering from marasmic kwashiorkor on admission, and during their whole re-feeding. The results have been compared with values obtained in control children of the same ethnic group and with normal children living in Belgium. Vitamin B-12 levels are high on admission and only normalize during the second month of re-feeding. TBBC is normal on admission but significantly increases during re-feeding.

Black People↗