Intake and absorption of tocopherol

Effects of acute alcohol consumption and vitamin E co-treatment on oxidative stress parameters in rats tongue

The aim of this study was to evaluate the effects of acute alcohol consumption and vitamin E co-treatment upon oxidative stress parameters in rats tongue. Thirty-eight, Wistar rats were separated into five groups (alcohol, alcohol/vitamin E, control, Tween, vitamin E). Alcohol and alcohol vitamin E groups had the standard diet, and 40% alcohol on drinking water. Other groups were fed with the same standard diet and water ad libitum. Vitamin E was given by gavage to vitamin E and alcohol/vitamin E rats twice a week. Alcohol and control groups were subjected to saline gavage and Tween group to 5% Tween 80 solution, the vitamin E vehicle. At day 14, the animals were anesthetized and specimens were obtained from tongue. Lipid peroxidation (TBARS), protein oxidative damage, catalase (CAT) and superoxide dismutase (SOD) activities were quantified. Alcohol group decreased TBARS in relation to control group and alcohol vitamin-treated animals decreased TBARS when compared to Tween and vitamin E groups. SOD activity was lower and CAT activity was higher in animals treated with both alcohol and vitamin E. These results suggest that short-term alcohol consumption decreases lipid peroxidation levels. Alternatively, alcohol/vitamin E group increased CAT, showing the toxicity of this association.

Development of alpha-tocopherol acetate nanoparticles: influence of preparative processes

We studied different methods of preparing alpha-tocopherol acetate (ATA) nanoparticles, which are to be used in targeting the lungs as aerosols in order to prevent cigarette smoke toxicity. Poly-(lactide) nanoparticles were prepared using nanoprecipitation and solvent evaporation techniques, which produced, respectively, too small and too large nanoparticles to be aerosolized. The emulsification-diffusion method produced 2 months stable nanoparticles with a size between (500-700 nm). Increasing ATA concentration (1-7 mg/mL) induced a decrease in the association rate (97-93%) and in the adsorbed ATA rate (7-4.5%), which was associated with variations of Zeta potentials (-27.5 to -24.3 mV) and decrease in polymeric wall thickness and density.

High levels of dietary unsaturated fat decrease alpha-tocopherol content of whole body, liver, and plasma of chickens without variations in intestinal apparent absorption

An experiment was designed to assess the effect of dietary unsaturated fat inclusion level on alpha-tocopherol apparent absorption and deposition in broiler chickens at 2 ages (20 and 39 d). The dietary fat was a mixture of linseed and fish oil, rich in polyunsaturated fatty acids (PUFA). The experimental treatments were the result of 4 levels of supplementation with alpha-tocopheryl acetate (0, 100, 200, and 400 mg/kg; E0, E100, E200, and E400 treatments, respectively) and 4 dietary oil inclusion levels (2, 4, 6, and 8%; O2, O4, O6, and O8 treatments respectively). Almond husk was used as an energy dilutor in the high-fat diets. Apparent absorption of total fatty acids was high in all treatments averaging 88% and was higher with high fat dietary inclusion level. alpha-Tocopheryl acetate hydrolysis and apparent absorption of alpha-tocopherol were similar in both ages and were not affected by fat inclusion level, except for a reduction of the absorption in the low-fat diet (O2) in the E100 treatment at 20 d of age. Despite this lack of differences in hydrolysis and absorption, higher-fat PUFA diets induced lower concentrations of free alpha-tocopherol in the excreta, at high alpha-tocopherol doses, suggesting an increase in the destruction of alpha-tocopherol by lipid oxidation in the gastrointestinal tract. Similarly, total and hepatic alpha-tocopherol deposition was lower in the birds fed high-PUFA diets in the E200- and E400-supplemented birds, possibly due to a destruction of vitamin E when protecting these PUFA from lipid peroxidation. alpha-Tocopherol concentration in liver and, to a lesser extent, in plasma was a useful indicator of the degree of response of this vitamin to different factors that can affect its bioavailability; however, in the present experiment, CV were too high to use liver and plasma concentrations as estimators of total body vitamin E.

Effect of meal fat quality on oxidation resistance of postprandial VLDL and LDL particles and plasma triacylglycerol level

This study was performed to examine the postprandial effects of meals containing dietary fats, with their natural fatty acid composition and tocopherol content, on the plasma triacylglycerols (TG) and tocopherols and on the resistance of VLDL and LDL to oxidation. On six separate days eighteen healthy male subjects were given low-fat meals (LF) or the LF meals enriched with sunflower oil (SO), rapeseed oil (RO), olive oil (OO), palm oil (PO), or butter (B) in a crossover design. The fat-rich meals all resulted in similar postprandial TG responses while the LF test meal did not increase plasma TG level. The postprandial plasma fatty acid profile changed to resemble the fatty acid composition of the ingested test fat. The α-tocopherol:γ-tocopherol ratios in postprandial plasma and VLDL samples were greater than in the test fats. We found that the resistance of VLDL particles to oxidation in the postprandial state as assessed from lag time was increased after the PO-rich meal as compared with the SO-rich meal (P=0·018), and the propagation rate was greater after the SO- and RO-rich meals compared with the others (P<0·001). The resistance of LDL particles to oxidation was unaffected by the meals. In postprandial VLDL samples, the content of α-tocopherol was greater after the OO- and SO-rich meals compared with the meal rich in PO (P=0·034 and 0·042 respectively). The γ-tocopherol content of VLDL was highest after RO-meal as compared with all other test meals (P=0·0019), and higher after SO as compared with B (P=0·0148). Large individual differences were noted. In conclusion, meals enriched with different fats lead to the formation of VLDL particles with varying resistance to oxidation.

Relationship between dietary unsaturation and vitamin E in poultry

Vitamin E requirements are linked to dietary polyunsaturated fatty acids (PUFA) content as a result of the protective effect of vitamin E from lipid peroxidation. On the other hand, it has been suggested that dietary PUFA interfere with vitamin E absorption. A 4 x 4 factorial study was planned to assess the effect of dietary vitamin E inclusion level (0, 100, 200 and 400 mg/kg) and degree of unsaturation (15, 34, 45 and 61 g PUFA/kg) on vitamin E apparent absorption and tissue deposition in poultry. A total of 192 female broiler chickens were used. A digestibility balance was carried out between 19 and 23 days of age to calculate apparent absorption of fat and vitamin E. The livers of 96 animals were obtained at 44 days of age for vitamin E determination. Increasing dietary levels of vitamin E reduced its apparent absorption. The more saturated diet reduced fat and vitamin E apparent absorption while PUFA levels from 34 to 61 g/kg did not modify this parameter but reduced the hepatic vitamin E concentration, suggesting a greater systemic use of this vitamin. These results suggest that PUFA do not limit vitamin E absorption, although they may increase its degradation in the gastrointestinal tract.

Vitamin metabolism and requirements in the micropremie

Vitamin metabolism and requirements are reviewed for the micropremie (1000 Pounds g birthweight), for parenteral and enteral feedings. Recommendations are presented in table format. Human milk fortifiers and special formulas for the preterm infant are reviewed. For parenteral nutrition, only MVI Pediatric is currently available in the United States. Two millimeters per kilogram is recommended for the micropremie as the most satisfactory method of providing supplemental vitamins in total parenteral nutrition solutions.

Prevention of phorbol myristate acetate-induced acute lung injury by alpha-tocopherol liposomes

Phorbol-myristate acetate (PMA) is commonly used to produce experimental edema and other tissue injuries in the lung. Lung injuries induced by the administration of PMA has been shown to be mediated mainly by neutrophils. Neutrophils recruited to the lower respiratory tract may damage lung tissues by releasing reactive oxygen species, neutral proteases, and lysosomal enzymes. The present study was conducted to investigate whether alpha-tocopherol, entrapped in dipalmitoylphosphatidylcholine liposomes and delivered directly to the lung, could counteract some of the PMA-induced lung injuries. Plain liposomes or alpha-tocopherol containing liposomes (8 mg alpha-tocopherol/kg body weight) were intratracheally instilled into the lungs of rats 24 hr prior to PMA exposure (25 micrograms/kg) and treated rats were killed 3 hr later. Lungs of control animals exposed to PMA developed an increase in lung weight and lipid peroxidation as well as a decrease in lung angiotensin converting enzyme (ACE) and alkaline phosphatase (AKP) activities. PMA treatment also caused an increase in myeloperoxidase (MPO) activity in the lung, suggestive of neutrophil infiltration. Pretreatment of PMA-treated rats with plain liposomes had no effect on PMA-induced injuries. In contrast, pretreatment of rats with liposomal alpha-tocopherol, 24 hr prior to PMA administration, resulted in a significant elevation of pulmonary alpha-tocopherol concentration, accompanied by a concomitant reduction in MPO activity and reversal of PMA-induced changes in lung edema, lipid peroxidation, ACE and AKP activities. These results appear to demonstrate that the intratracheal administration of a liposome-associated lipophilic antioxidant, such as alpha-tocopherol, can significantly ameliorate the toxic effects of reactive oxygen species, putatively released from PMA-stimulated pulmonary target cells and infiltrating neutrophils.

Effect of dietary vitamin E on lipofuscin accumulation with age in the rat brain

We investigated the effect of dietary vitamin E on lipofuscin accumulation with age in the hippocampus, the inferior olive and the cerebellum of young (3-5 months old) middle-aged (12-14 months old) and old (24-26 months old) male Sprague-Dawley rats. The rats were fed either a vitamin E-deficient diet, vitamin E-supplemented diet or a control diet after reaching four weeks old. We employed both quantitative light microscopy using semithin sections and qualitative fluorescence microscopy for the analysis of lipofuscin accumulation with age. The concentrations of alpha-tocopherol were measured simultaneously in both the plasma and the three brain regions investigated. The effect of vitamin E deficiency was statistically significant only in the inferior olive of young rats and in all the three brain regions of middle-aged rats. The effect of vitamin E supplementation was statistically significant in all three brain regions of middle-aged rats. There was no statistically significant effect of vitamin E deficiency or supplementation on lipofuscin accumulation with age as compared with the control rats in all three brain regions of old rats. It was thus revealed that dietary vitamin E clearly had a significant effect on lipofuscin accumulation with age in the rat brain up until middle age, and that the same effect became indistinct in the latter half of their life.

Liposomes in pulmonary applications: physicochemical considerations, pulmonary distribution and antioxidant delivery

The application of liposomes for improved drug delivery to the lung is promising. Liposome-mediated pulmonary drug delivery promotes an increase in drug retention-time in the lung and more importantly, a reduction in extrapulmonary side-effects, invariably resulting in enhanced therapeutic efficacies. The engineering of an effective liposomal drug formulation for inhalation therapy must take into consideration the leakage problem associated with the nebulization process; vesicle stability and release kinetics within the pulmonary milieu; and, the altered pharmacokinetics of the entrapped drug. The delivery of liposome-entrapped antioxidants via the tracheobronchial route has been found to be very useful in increasing the half-times of the administered agents, thus providing a sustained release effect for prolonged drug action. The entrapment in liposomes of alpha-tocopherol, an extremely insoluble but highly effective antioxidant, has been shown to be very effective in ameliorating oxidant-induced injuries in the lung. The use of bifunctional liposomes containing two antioxidants have been determined to provide excellent resistance to an oxidative challenge and appears to hold promise for improved clinical applications in antioxidant therapy.

Disposition kinetics and dosage regimen of vitamin E administered intramuscularly to sheep

Three experiments were conducted to estimate the effects of single intramuscular (IM) administrations of vitamin E on blood plasma and tissue concentrations of alpha-tocopherol in sheep. In Expt 1, plasma kinetics of alpha-tocopherol in sheep (n 30) were investigated following IM administration of three doses (ten sheep/dose) of DL-alpha-tocopheryl acetate, (20, 40 and 60 mg/kg live weight). Plasma profiles of alpha-tocopherol consisted of a lag phase followed by an apparent first-order absorption and elimination phase. The rate of absorption and elimination, as well as the lag phase, were independent of the dose, but the extent of absorption was directly proportional to dose. In Expt 2 (eighteen experimental and five control sheep), the animals were injected as in Expt 1 and were killed at 0, 80 and 176 h. Increases in alpha-tocopherol levels in organs were much higher than in plasma. Some tissues such as liver, spleen, lung and adrenal appeared to exhibit rapid absorption and elimination phases. The amount absorbed was proportional to the dose administered. Other organs such as heart, kidney and pancreas had a slow elimination rate. In Expt 3, D-alpha-tocopherol was injected IM into ten sheep at either 604 mg or 1208 mg. The mean hepatic alpha-tocopherol concentrations in both groups rose rapidly and after 4 weeks of dosing its concentrations were higher than the predosing levels. The increase in hepatic tocopherol concentrations were higher following 1208 mg dosing than 604 mg D-alpha-tocopherol. No simple relationship existed between plasma and hepatic alpha-tocopherol concentrations. This suggests a difference in body mechanisms controlling vitamin E in blood and liver.

Absorption, transport and metabolism of vitamin E

Vitamin E includes eight naturally occurring fat-soluble nutrients called tocopherols and dietary intake of vitamin E activity is essential in many species. alpha-Tocopherol has the highest biological activity and the highest molar concentration of lipid soluble antioxidant in man. Deficiency of vitamin E may cause neurological dysfunction, myopathies and diminished erythrocyte life span. alpha-Tocopherol is absorbed via the lymphatic pathway and transported in association with chylomicrons. In plasma alpha-tocopherol is found in all lipoprotein fractions, but mostly associated with apo B-containing lipoproteins in man. In rats approximately 50% of alpha-tocopherol is bound to high density lipoproteins (HDL). After intestinal absorption and transport with chylomicrons alpha-tocopherol is mostly transferred to parenchymal cells of the liver were most of the fat-soluble vitamin is stored. Little vitamin E is stored in the non-parenchymal cells (endothelial, stellate and Kupffer cells). alpha-Tocopherol is secreted in association with very low density lipoprotein (VLDL) from the liver. In the rat about 90% of total body mass of alpha-tocopherol is recovered in the liver, skeletal muscle and adipose tissue. Most alpha-tocopherol is located in the mitochondrial fractions and in the endoplasmic reticulum, whereas little is found in cytosol and peroxisomes. Clinical evidence from heavy drinkers and from experimental work in rats suggests that alcohol may increase oxidation of alpha-tocopherol, causing reduced tissue concentrations of alpha-tocopherol. Increased demand for vitamin E has also been observed in premature babies and patients with malabsorption, but there is little evidence that the well balanced diet of the healthy population would be improved by supplementation with vitamin E.

Effects of dietary vitamin E on the biosynthesis of 5-lipoxygenase products by rat polymorphonuclear leukocytes (PMNL)

Activation of polymorphonuclear neutrophils (PMNL) leads to the release of arachidonate from cellular phospholipids via a phospholipase A2, and conversion of products of the 5-lipoxygenase pathway. Evidence to date indicates the dietary vitamin E ((R,R,R)-alpha-tocopherol) can influence both cyclooxygenase and phospholipase A2 activities and that the effect of this vitamin is cell/tissue specific. The present study was undertaken in order to examine the effects of varying dietary tocopherol on PMNL tocopherol content and 5-lipoxygenase product profile using the ionophore A23187 as stimulant in the presence and absence of exogenous arachidonate. Feeding semi-purified diets containing 0, 30 or 3000 ppm of (R,R,R)-alpha-tocopherol acetate to weanling rats for 17 weeks resulted in a dose-related enrichment of PMNL tocopherol. Stimulation of PMNL elicited a significant and rapid loss of tocopherol. When PMNL were stimulated with A23187 alone, the synthesis of 5-HETE, LTB4 and 19-hydroxy-LTB4 was decreased in proportion to increasing dietary tocopherol concentrations. However, when exogenous arachidonate was provided with A23187, intermediate amounts of dietary tocopherol (30 ppm) still suppressed the formation of 5-lipoxygenase products, but high doses (3000 ppm) did not have any additional inhibitory effect. This differential response to high concentrations of vitamin E in the presence and absence of exogenous arachidonate highly suggest that at these concentrations, tocopherol may act principally at the level of substrate release whereas at lower concentrations, 5-lipoxygenase is inhibited. Data from this study demonstrated that attenuation of the formation of 5-lipoxygenase products in PMNL can be achieved by dietary vitamin E enrichment.

Vitamin E fails to alter the aggregation and the oxygenated metabolism of arachidonic acid in normal human platelets

Using low doses of vitamin E, either in vitro or in vivo, we have succeeded in almost doubling plasma and platelet alpha-tocopherol in healthy humans. Despite such an enrichment, platelet aggregation induced by collagen and thromboxane A2 minetic U46619 was not much affected, although that induced by exogenous arachidonic acid was significantly decreased. Similarly, the oxygenation of exogenous arachidonic acid was not modified. When incubated with thrombin some variations in the formation of endogenous cyclooxygenase and lipoxygenase products could be observed, although rarely significantly. The tendency was a decrease after in vivo enrichment and an increase when enrichment occurred in vivo. Serum oxygenated metabolites of arachidonic acid as well as urinary metabolites of thromboxane and prostacyclin were also not affected after vitamin E supplementation. Since the lipoxygenation of eicosapentaenoic acid was very strongly peroxide-dependent, the effect of alpha-tocopherol enrichment was tested and the 12-hydroperoxide derivative of arachidonic acid was used as a physiological peroxide. No modification could be observed, confirming that vitamin E does not alter the specific peroxidation of polyunsaturated fatty acids in normal platelets. We conclude that vitamin E supplementation neither affects arachidonic acid-dependent aggregation nor the oxygenated metabolism of arachidonic acid in normal human platelets.

Transport and distribution of alpha-tocopherol in lymph, serum and liver cells in rats

Rats were cannulated in the major mesenteric lymph duct and given an intraduodenal bolus of unlabeled and alpha-[3H]tocopherol, and [14C]oleic acid in soybean oil. The appearance of alpha-tocopherol in lymph was negligible during the first 2 h and peaked 4-15 h after feeding, whereas no detectable amount was recovered in the portal vein. Intestinal absorption via the lymphatic pathway was 15.4 +/- 8.9% (n = 10) and 45.9 +/- 10.8% (n = 4) for alpha-tocopherol and [14C]oleic acid, respectively. About 99% of alpha-tocopherol in lymph was associated with the chylomicron fraction (d less than 1.006 g/ml). In non-fasting rats, 51% of serum alpha-tocopherol was associated with chylomicrons/VLDL (very-low-density lipoprotein, d less than 1.006 g/ml) and 47% with HDL (high-density lipoprotein, 1.05 less than d less than 1.21 g/ml). Our study revealed that the liver, skeletal muscle and adipose tissue contain approx. 92% of the total mass of alpha-tocopherol measured in ten different organs. Parenchymal and nonparenchymal liver cells contributed to 75% and 25% of the total mass of alpha-tocopherol in the liver, respectively.

Long-term assessment of growth, nutritional status, and gastrointestinal function in survivors of necrotizing enterocolitis

The long-term effect of necrotizing enterocolitis on growth, nutritional status, and gastrointestinal function was assessed in premature infants at the age of 1 year. Of the 22 of 40 infants who developed NEC, 18 were given medical treatment and four required surgical treatment consisting of intestinal resection of less than one fourth of the small bowel. Eighteen infants who did not develop NEC served as controls. At 1 year follow-up, NEC survivors and controls had normal and comparable anthropometric measurements, biochemical values (serum iron, albumin, prealbumin, retinol binding protein, liver function studies) and gastrointestinal tract function (vitamin E absorption, fasting serum bile acids concentration, lactose breath test). This study demonstrates that, in the absence of short bowel syndrome, there is no detectable long-term effect on growth, nutritional status, and gastrointestinal tract function in premature infants who had NEC in the newborn period.

The effect of vitamin E on the healing of gingival wounds in rats

Forty male and female albino rats received a standardized gingival wound (gingivectomy) between the mandibular incisor teeth. One half of the animals received 60 I.U. of d-alpha-tocopheryl acetate daily, administered orally by pipette. An additional control group of 20 animals was not wounded and half of these animals received 60 I.U. of d-alpha-tocopheryl daily. Four animals in each of the two gingivectomy groups (Groups 1, 2) were sacrificed at periods of 1, 2, 4, 7 and 14 days following gingivectomy. Two animals in each of two control unwounded groups (Groups 3, 4) were sacrificed at similar times. Gingival healing was studied grossly and histologically. The animals receiving the vitamin E supplements healed more rapidly, with almost complete restoration of gingiva by 7 days. Complete healing was seen in both control and experimental groups by 14 days. Vitamin E was shown to accelerate gingival wound healing in experimental animals.

Vitamin E inhibition of hamster buccal pouch carcinogenesis. A gross, histologic, and ultrastructural study

Sixty-four young adult male and female golden hamsters (Mesocricetus auratus) were divided into four equal experimental groups of sixteen animals. In Group 1 animals the left buccal pouch was painted three times weekly with a 0.25 percent solution of 7, 12-dimethylbenz(a)anthracene (DMBA) in heavy mineral oil. In Group 2 animals the left buccal pouch was similarly painted with DMBA, but the animals also received 7 I.U. of vitamin E (alpha tocopherol) twice weekly on days alternate to the DMBA painting. The vitamin E was administered orally via a fine pipette. Group 3 animals were similarly painted with DMBA and received vitamin E vehicle by pipette. Group 4 animals served as untreated controls. Four animals in each group (two male, two female) were killed at 8, 10, 12, and 14 weeks. Buccal pouches were photographed and excised. Tumors were noted and measured in the left buccal pouches. The buccal pouches as well as major organs were fixed in formalin, sectioned in paraffin, and stained with hematoxylin and eosin. In the Group 2 animals receiving vitamin E, there was a significant delay in tumor formation so that by 12 to 14 weeks there were fewer tumors and their average size was smaller than those in the Group 1 and Group 3 animals painted with DMBA but receiving no vitamin E supplement. Microscopic examination revealed that there was less invasion of underlying tissues and less surface necrosis. The tumors in both control and vitamin E groups were well-differentiated epidermoid carcinomas. No differences in the nature of the cellular patterns of the carcinomas in control and vitamin E groups were revealed by electron microscopic studies.

Effects of the type of dietary fat at two levels of vitamin E in Wistar male rats during development and aging. I. Life span, serum biochemical parameters and pathological changes

This experiment was designed to study in rats the implications of the dietary type of fat at two levels of vitamin E on the life span as well as on several biochemical and anatomopathological age-related changes. For this purpose, six different isoenergetic diets containing 15% coconut oil (SFD), safflower oil (UFD) or a combination of both (CFD) with 2 or 200 mg% of dl-alpha-tocopherol were offered ad libitum to outbred Wistar male rats from weaning to senescence. The results indicated that up to 9--12 months the body weights of rats consuming the CFD or the UFD increased generally faster than those fed the SFD, and that all rats developed moderate degrees of obesity. Age-dependent changes in organ weights (kidneys, testes, spleen, brain, liver and heart) were unaffected by diet. Serum levels of vitamin E generally reflected the corresponding dietary levels, but were also influenced by the type of dietary fat. Serum cholesterol levels were not significantly affected by the type of diet or by age. Only transient hypotriglyceridemic and hypophospholipidemic effects of the UFD were observed and, while the levels of triglycerides decreased with age up to the 18th month followed by an increase at 24 months, the levels of serum phospholipids remained unchanged. Neither diet nor age modified the serum albumin/globulin ratios. While no differences in maximum life span were found between dietary groups, the 50% survival time of rats fed the UFD at high level of vitamin E was significantly longer than in all the other groups. This beneficial effect was related to postponement of the onset and reduction of incidence of malignant neoplasms, but was apparently not related to any particular influence on the incidence or severity of chronic nephropathy which practically developed in all rats. Various neoplastic, degenerative and inflammatory diseases encountered in rats dying during the course of the experiment were tabulated and compared with similar findings reported by others in different strains of rats. Pituitary and adrenocortical adenomas as well as adrenocortical and renal carcinomas were the most frequent tumors found in this study. All the pathological changes provided useful baseline information for the evaluation of data presented in this and subsequent communications of this series of studies.

The occurrence and effects of human vitamin E deficiency. A study in patients with cystic fibrosis

The role of vitamin E in human nutrition was studied by investigation of patients with cystic fibrosis (CF) and associated pancreatic insufficiency. Vitamin E status was assessed by measurement of the plasma concentration of the principal circulating isomer, alpha-tocopherol. Results of such determinations in 52 CF patients with pancreatogenic steatorrhea revealed that all were deficient in the vitamin. The extent of decreased plasma tocopherol varied markedly but correlated with indices of intestinal malabsorption, such as the serum carotene concentration and percentage of dietary fat absorbed. Supplementation with 5-10 times the recommended daily allowance of vitamin E in a water-miscible form increased the plasma alpha-tocopherol concentrations to normal in all 19 CF patients so evaluated. Studies on the effects of vitamin E deficiency focused on possible hematologic alterations. An improved technique was developed to measure erythrocyte hemolysis in vitro in the presence of hydrogen peroxide. While erythrocyte suspensions from control subjects demonstrated resistance to hemolysis during a 3-h incubation, all samples from tocopherol-deficient CF patients showed abnormal oxidant susceptibility, evidenced by greater than 5% hemoglobin release. The degree of peroxide-induced hemolysis was related to the plasma alpha-tocopherol concentration in an inverse, sigmoidal manner. The possibility of in vivo hemolysis was assessed by measuring the survival of (51)Cr-labeled erythrocytes in 19 vitamin-E deficient patients. A moderate but statistically significant decrease in the mean (51)Cr erythrocyte half-life value was found in this group. Measurement of erythrocyte survival before and after supplementation of 6 patients with vitamin E demonstrated that the shortened erythrocyte lifespan could be corrected to normal with this treatment. Other hematologic indices in deficient subjects, however, were normal and did not change upon supplementation with vitamin E. It is concluded that CF is invariably associated with vitamin E deficiency, provided that the patient in question has pancreatic achylia and is not taking supplementary doses of tocopherol. Concomitant hematologic effects consistent with mild hemolysis, but not anemia, occur and may be reversed with vitamin E therapy. Patients with CF should be given daily doses of a water-miscible form of vitamin E to correct the deficiency.