The relative importance of the factors involved in the absorption of vitamin E in children

Formation of RRR-α-tocopherol in rumen and intestinal digestibility of tocopherols in dairy cows

Tocopherol sources in diets are often a combination of all-rac-α-tocopheryl acetate (synthetic α-tocopherol) from vitamin supplements and natural tocopherols and 2R-(4'R, 8'R)-5,7,8-trimethyltocotrienol (α-tocotrienols) from the feed sources. Synthetic α-tocopherol consists of 8 different stereoisomers including 2R-(4'R, 8'R)-5,7,8-trimethyltocol (RRR-α-tocopherol), 2R-(4'S, 8'R)-5,7,8-trimethyltocol (RSR-α-tocopherol), 2R-(4'R, 8'S)-5,7,8-trimethyltocol (RRS-α-tocopherol), 2R-(4'S, 8'S)-5,7,8-trimethyltocol (RSS-α-tocopherol), 2S-(4'S, 8'S)-5,7,8-trimethyltocol (SSS-α-tocopherol), 2S-(4'R, 8'S)-5,7,8-trimethyltocol (SRS-α-tocopherol), 2S-(4'S, 8'R)-5,7,8-trimethyltocol (SSR-α-tocopherol), and 2S-(4'R, 8'R)-5,7,8-trimethyltocol (SRR-α-tocopherol). The pre-absorption metabolism of tocopherols and tocotrienols in ruminants differs from monogastric animals due to the extensive microbial fermentation in the anaerobic rumen. The current study investigated the impact of toasting and decortication of oats on metabolism in the digestive tract (synthesis, digestion), and intestinal digestibility of tocopherols in dairy cows by using 4 ruminal and intestinal cannulated Danish Holstein cows in a 4 × 4 Latin square design for 4 periods. Cows were fed a total mixed ration ad libitum containing different forms of oats: whole oat, decorticated oat, toasted oat, and decorticated toasted oat, all rolled before mixed ration. Overall means across 4 treatments were statistically analyzed, testing whether overall means were different from zero. Decortication or toasting did not affect the balance or digestibility of α-tocopherols in rumen. Average across treatments showed the ruminal degradation of synthetic α-tocopherol (279 mg/d, P = 0.02; P-value shows that average across treatments is different from zero), synthetic 2R-α-tocopherol (133 mg/d, P < 0.01; summation of RRS-, RSR- and RSS-α-tocopherol), and 2S-α-tocopherol (190 mg/d; P < 0.01, summation of SSS-, SRS-, SSR, and SRR-α-tocopherol), while RRR-α-tocopherol was formed in the rumen (221 mg/d, P = 0.10). The average across treatments showed that small intestinal digestibility of tocopherols ranked in the following order: α-tocotrienol > natural α-tocopherol > synthetic α-tocopherols > 2R-(4'R, 8'R)-,7,8-dimethyltocol (γ-tocopherol). The average across treatments for small intestinal and feed-ileum digestibility ranked in the following order: RRR-α-tocopherol > synthetic 2R-α-tocopherol > 2S-α-tocopherol. Results showed the first evidence for RRR-α-tocopherol formation under anaerobic conditions in the rumen. In addition, synthetic α-tocopherol stereoisomers, γ-tocopherol and α-tocotrienol were degraded in the rumen. There was a discrimination against absorption of synthetic 2R- and 2S-α-tocopherol in the small intestine.

Anti-Oxidant Drugs: Novelties and Clinical Implications in Cerebellar Ataxias

BACKGROUND

Hereditary cerebellar ataxias are a group of disorders characterized by heterogeneous clinical manifestations, progressive clinical course, and diverse genetic causes. No disease modifying treatments are yet available for many of these disorders. Oxidative stress has been recurrently identified in different progressive cerebellar diseases, and it represents a widely investigated target for treatment.

OBJECTIVE

To review the main aspects and new perspectives of antioxidant therapy in cerebellar ataxias ranging from bench to bedside.

METHOD

This article is a summary of the state-of-the-art on the use of antioxidant molecules in cerebellar ataxia treatments. It also briefly summarizes aspects of oxidative stress production and general characteristics of antioxidant compounds.

RESULTS

Antioxidants represent a vast category of compounds; old drugs have been extensively studied and modified in order to achieve better biological effects. Despite the vast body of literature present on the use of antioxidants in cerebellar ataxias, for the majority of these disorders conclusive results on the efficacy are still missing.

CONCLUSION

Antioxidant therapy in cerebellar ataxias is a promising field of investigations. To achieve the success in identifying the correct treatment more work needs to be done. In particular, a combined effort is needed by basic scientists in developing more efficient molecules, and by clinical researchers together with patients communities, to run clinical trials in order to identify conclusive treatments strategies.

Vitamin E and neurodegeneration

Alpha-tocopherol (vitamin E) is a plant-derived antioxidant that is essential for human health. Studies with humans and with animal models of vitamin E deficiency established the critical roles of the vitamin in protecting the central nervous system, and especially the cerebellum, from oxidative damage and motor coordination deficits. We review here the established roles of vitamin E in protecting cerebellar functions, as well as emerging data demonstrating the critical roles of alpha-tocopherol in preserving learning, memory and emotive responses. We also discuss the importance of vitamin E adequacy in seemingly unrelated neurological disorders.

Double-balloon jejunal perfusion to compare absorption of vitamin E and vitamin E acetate in healthy volunteers under maldigestion conditions

BACKGROUND/OBJECTIVES

The vitamin E derivative, α-tocopheryl acetate, is often included in formulations used in enteral nutrition. In this respect, we compared α-tocopherol and α-tocopheryl acetate absorption under 'maldigestion' conditions, such as occurring during enteral tube feeding, using differentially labeled RRR-[5,7-methyl-((2)H(6))]-α-tocopherol and RRR-[5-methyl-(2)H(3)]-α-tocopheryl acetate allowing direct comparison between free and esterified forms.

SUBJECTS/METHODS

The two derivatives were given together in a single dose to six volunteers directly into the jejunum using a double-balloon perfusion system. Perfusion lasted for 1 h, and the collected blood and effluent samples were analyzed by liquid chromatography-mass spectrometry.

RESULTS

In the isolated 20-cm length of exposed jejunum, on average ~ 6% of the two vitamin E forms were absorbed >1 h based on subtraction of effluent from influent. There was substantial difference in the absolute absorbed quantity between individuals, but no significant differences were observed in the absorption between the two labeled forms as assessed in the plasma. (2)H(3)-α-tocopherol was not present in the influent, but appeared in the effluent, indicating that the acetylated form of vitamin E is cleaved by brush border enzymes in the small intestine.

CONCLUSIONS

This study shows that even in the absence of digestive enzymes and bile salts, the appropriately solubilized acetylated form of α-tocopherol exhibits the same bioavailability as free α-tocopherol. This suggests that both forms can be absorbed equally under maldigestion conditions such as present clinically during enteral tube feeding.

Vitamin E and neurological function

The clinical, neuropathological and electrophysiological evidence that vitamin E (alpha-tocopherol) is essential for normal neurological function will be reviewed. The possible reasons why neural tissues should be particularly affected by a deficiency of this fat-soluble vitamin and the mechanism(s) involved will be considered.

Isolated vitamin E deficiency with demyelinating neuropathy

A 22-year-old man, with a past history of generalized tonic-clonic seizures treated with phenobarbital, presented with spinocerebellar ataxia. The electrophysiological studies revealed a demyelinating motor-sensory neuropathy. The serum vitamin E level was low. Sural nerve biopsy revealed loss of large myelinated fibers with evidence of remyelination. Vitamin E supplementation led to clinical and electrophysiological recovery of sensory conduction and evoked potentials. Motor nerve conduction, however, showed only partial recovery. Vitamin E deficiency leading to a demyelinating neuropathy, as in the present case, suggests that the full spectrum of the disease entity is not fully defined.

Neurological complications of coeliac disease

A variety of neurological disorders have been reported in association with coeliac disease including epilepsy, ataxia, neuropathy, and myelopathy. The nature of this association is unclear and whether a specific neurological complication occurs in coeliac disease remains unproved. Malabsorption may lead to vitamin and trace element deficiencies. Therefore, patients who develop neurological dysfunction should be carefully screened for these. However, malabsorption does not satisfactorily explain the pathophysiology and clinical course of many of the associated neurological disorders. Other mechanisms proposed include altered autoimmunity, heredity, and gluten toxicity. This review attempts to summarise the literature and suggests directions for future research.

Interdependence of serum concentrations of vitamin K1, vitamin E, lipids, apolipoprotein A1, and apolipoprotein B: importance in assessing vitamin status

Vitamin E (alpha-tocopherol) and vitamin K1 (phylloquinone) are fat-soluble vitamins and are important nutrients in health and disease. In this study serum concentrations of vitamin E and vitamin K1, lipids and apolipoproteins A1 and B were measured in neonates, normal and hyperlipidaemic individuals in an attempt to establish their interrelationships. A high degree of correlation was observed between the concentrations of the vitamins and those of lipids and apolipoproteins (r ranged from 0.42 to 0.92; p<0.001). Stepwise linear regression methods determined that serum concentrations of both vitamin E and vitamin K1 could best be predicted by using equations excluding lipids but containing only apolipoprotein A1 and B concentrations. Correlation coefficients between predicted and measured values were 0.89 for serum vitamin E, and 0.83 for serum vitamin K1 concentrations. To test the validity of the derived formulae, measured and estimated vitamin K1 and vitamin E concentrations in serum were determined in another group of neonates, normal adults and hypercholesterolemic adults and the comparisons were shown to be very good. These results indicate that the serum levels of both vitamins depend critically on the concentration of the lipoprotein carriers, apolipoproteins A1 and B. Hence, in order to identify variations in serum vitamin K1 and vitamin E concentrations, which are independent of variations in carrier concentration, it will be necessary to express these serum vitamins as ratios of vitamins to apolipoprotein A1 and B carriers.

Electrophysiologic recovery after vitamin E-deficient neuropathy

A case report is presented of an electrophysiologic recovery from vitamin E-deficient neuropathy after treatment with water-soluble vitamin E in a patient with chronic hepatobiliary disease. The patient was a 64-year-old man who had experienced progressive difficulty in ambulation, with ataxia, over the previous 3 years. The symptoms were associated with pain, tingling sensation in the extremities, and reduced fine motor activity. The patient had chronic hepatobiliary disease, with recurrent cholangitis and external drainage of bile acid through a T-tube for more than 20 years. Vitamin E level was barely detectable (<0.5 mg/L). Sensory conduction was absent in both sural nerves. Other sensory and motor conduction studies in the upper and lower extremities showed decreased amplitude. The patient was treated with water-soluble vitamin E. After 4 months of therapy, his ambulation function improved, but pain and tingling sensation in both hands remained. Sensory nerve action potentials appeared in both sural nerves, and amplitudes of other sensory nerves were increased. In a second follow-up study after 9 months, all of the evaluated parameters in the nerve conduction studies, as well as the vitamin E level, were normal. The authors conclude that vitamin E-deficient neuropathy is reversible and electrophysiologic recovery can occur with water-soluble vitamin E therapy.

A vitamin E-deficient diet affects nerve regeneration in rats

Degenerative changes in the neuromuscular system have been found in animals and humans with vitamin E (E) deficiency. This morphologic study examined the effect of dietary E on the regeneration of peripheral nerves in male Sprague-Dawley rats. After feeding an E-sufficient diet (dl-alpha-tocopheryl acetate 50 mg/kg diet) for 6 d, 24 rats were randomly and equally assigned to one of three groups: control (CTRL) fed an E-sufficient diet for 43 d without surgery, normal (NE) fed an E-sufficient diet, or low (LE) fed an E-deficient diet (dl-alpha-tocopheryl acetate 0 mg/kg diet). After 22 d of feeding, NE and LE had surgical compression of the right sciatic nerve and continued eating for 15 d. On day 43, the right triceps surae muscles and a segment of the right sciatic nerve were removed, then all rats were euthanized. The nerve and muscles were processed for morphologic analyses. Presurgery and postsurgery LE ate less food (P < 0.048 and P < 0.001, respectively), which resulted in a lower body weight gain (P < 0.0002). LE had irregularly shaped and less myelinated axons than NE (P < 0.0001) and CTRL (P < 0.0001). The LE plantaris muscle had less type II fibers when compared with NE (P < 0.007) and CTRL (P < 0.03). The results suggest that an E-deficient diet affects food intake, impairs nerve regeneration, and decreases type II fibers, whereas an E-sufficient diet contributes to normal axon regeneration.

Vitamin E serum levels in Rett syndrome

In order to study the role of vitamin E in the pathogenesis of Rett syndrome (RS), we analysed vitamin E serum levels in twenty-eight patients affected by this disorder. We found lower vitamin E serum levels in nine cases (32.1%). These results indicated that the oxidative free radical metabolism may be impaired in a significant percentage of Rett syndrome patients suggesting the need for further studies of tissue vitamin E in different brain regions.

Fat-soluble vitamin concentration in chronic alcohol-induced pancreatitis. Relationship with steatorrhea

In order to study the fat-soluble vitamin concentration of patients with chronic alcohol-induced pancreatitis (CAIP) we measured vitamins A and E, total lipids, and retinol-binding protein (RBP) in the plasma of 44 patients with CAIP and 83 controls (44 healthy controls; 39 Crohn's disease patients). Mean plasma vitamin E and vitamin E/total lipid ratio were significantly lower in CAIP when compared with either control or Crohn's disease groups. A low vitamin E/total lipid ratio was found in 75% of CAIP patients (91% with steatorrhea) and a ratio less than 1.0 was virtually 100% predictive of steatorrhea. The mean plasma vitamin A level for the CAIP group was significantly lower (overall 16%, 38% with steatorrhea) than in controls. Patients with CAIP show subnormal plasma levels vitamin E more often as compared to vitamin A. Further, the plasma vitamin E/total lipids ratio may be a sensitive and practical means in the detection and follow-up of steatorrhea in these patients.

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.

Ocular pathologic features of arteriohepatic dysplasia (Alagille's syndrome)

Arteriohepatic dysplasia (Alagille's syndrome), an autosomal dominant condition involving jaundice caused by a developmental scarcity of intrahepatic bile ducts, has characteristic cardiovascular, skeletal, facial, and ocular features that distinguish it from extrahepatic biliary atresia and an array of other neonatal intrahepatic cholestatic disorders. Two children who died of this syndrome had prominent Schwalbe's rings with attached iris strands characteristic of Axenfeld's syndrome. Additional histologic findings of iris atrophy and stromal nodules, however, made the designation Axenfeld-Reiger's syndrome more appropriate. Pigmentary retinopathy, degeneration of Bruch's membrane, and prominent lipofuscin deposition in the ciliary muscle noted in one of the patients were not regarded as primary changes of Alagille's syndrome, but were believed to be secondary to acquired deficiency of the fat-soluble vitamins A and E. Early recognition of the ocular changes in arteriohepatic dysplasia is helpful in establishing the proper diagnosis to avoid unnecessary abdominal surgery and institute vitamin therapy.

Vitamin E deficiency in primary biliary cirrhosis: gastrointestinal malabsorption, frequency and relationship to other lipid-soluble vitamins

In contrast to deficiencies of vitamins A, D and K, little is known of the prevalence, clinical manifestations and mechanisms of vitamin E deficiency in adult patients with cholestasis. We measured serum vitamin E levels in 45 patients with primary biliary cirrhosis, 20 with primary sclerosing cholangitis, 9 with cryptogenic cirrhosis and 12 with alcoholic cirrhosis. To correct for the hyperlipidemia often found in patients with primary biliary cirrhosis and primary sclerosing cholangitis, total serum lipids were measured and vitamin E levels were expressed as the vitamin E/total serum lipid ratio. Serum vitamin A and D levels and prothrombin time were also determined. Six of 45 patients with primary biliary cirrhosis (13%) but none of the patients with sclerosing cholangitis, cryptogenic cirrhosis or alcoholic cirrhosis and subnormal vitamin E/total serum lipids ratios. Vitamin E deficiency was found in two of eight patients with asymptomatic primary biliary cirrhosis. There was no correlation between standard liver biochemical tests, fasting serum cholylglycine and vitamin E levels. Patients with primary biliary cirrhosis and primary sclerosing cholangitis had significantly lower vitamin E/total serum lipids ratios than patients with either cryptogenic or alcoholic cirrhosis. Twenty-three percent of patients with primary biliary cirrhosis were vitamin D deficient and 14% had low vitamin A levels. Two of the six patients with vitamin E deficiency were also deficient in vitamin D, only one was vitamin A deficient and none had prolonged prothrombin time. We also investigated the gastrointestinal absorption of vitamin E in nine patients with primary biliary cirrhosis and normal vitamin E levels as well as in six normal controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin E and neurologic function in man

Despite the well-known detrimental effect of vitamin E deficiency on the nervous system of many experimental animal models for decades, only over the past decade has vitamin E become recognized as essential for the maintenance of the structure and function of the human nervous system. This discovery of the neurologic role of vitamin E in man is due primarily to the identification of a degenerative neurologic syndrome in children and adults with chronic vitamin E deficiency caused by gastrointestinal diseases impairing fat and vitamin E absorption. A compelling body of clinical, neuropathologic, and therapeutic response evidence conclusively demonstrates that vitamin E deficiency is responsible for the neurologic disorder seen in such patients. In addition, an inborn error in vitamin E metabolism, the Isolated Vitamin E Deficiency Syndrome, causes vitamin E deficiency and similar neurologic degeneration in the absence of fat malabsorption. Guidelines for the evaluation and treatment of vitamin E deficiency in relevant clinical circumstances are provided. The possible role of vitamin E in treating other neurologic diseases is discussed.

Accumulation of ceroid in smooth muscle indicates severe malabsorption and vitamin E deficiency

Four patients had accumulation of ceroid in smooth muscle (lipofuscinosis), which indicated severe or uncontrolled malabsorption, with confirmed vitamin E deficiency in three cases. The distribution of the pigment was systematic, and there seemed to be an association between malabsorption syndrome and vitamin E deficiency. Vitamin E supplementation seems to be indicated in such patients, and it is suggested that studies of smooth muscle function should be made in cases of heavy accumulation of ceroid.

Vitamin E deficiency and its clinical significance in adults with primary biliary cirrhosis and other forms of chronic liver disease

The vitamin E status of 146 adults with chronic liver disease was assessed by estimating both their serum vitamin E concentration and the ratio of serum vitamin E to serum cholesterol concentration. Low levels of vitamin E occurred most frequently in patients with primary biliary cirrhosis and other forms of chronic cholestatic liver disease. When a serum vitamin E concentration of 12.3 mumol/l (mean-2 SD of a control population) was taken as the lower limit of normal, 44% of patients with primary biliary cirrhosis and 32% with other chronic cholestatic liver disease had a reduced concentration, indicating a biochemical deficiency of vitamin E. If a vitamin E/total cholesterol ratio of 2.35 mumol/mmol was taken as the lower limit of normal, then 64% and 43% of patients with primary biliary cirrhosis and other chronic cholestatic liver disease, respectively, had a biochemical deficiency of vitamin E. Of the patients with chronic cholestasis and a serum bilirubin concentration greater than 100 mumol/l, 91% had a reduced vitamin E/cholesterol ratio. Twelve patients with primary biliary cirrhosis and severe vitamin E deficiency (serum vitamin E less than 5.0 mumol/l and a vitamin E/cholesterol ratio less than 1.0 mumol/mmol) underwent extensive neurological investigation. Five had a mild mixed sensorimotor peripheral neuropathy, which was not, however, typical of the neurological syndrome associated with vitamin E deficiency. In patients with severe biochemical deficiency of vitamin E (less than 5 mumol/l and less than 1 mumol/mmol total cholesterol), administration of large oral doses of vitamin E only increased serum concentrations to within the normal range in one patient; in the others even weekly parenteral administration over a 3-month period did not correct deficiency. In patients with less severe biochemical deficiency, the serum vitamin E concentration and vitamin E/total cholesterol ratio were restored to normal by oral or intramuscular supplements of the vitamin.

Serum vitamin E concentrations are normal in Friedreich's ataxia

Serum vitamin E concentrations and vitamin E:cholesterol ratios in 31 patients with Friedreich's ataxia were not significantly different from values obtained from either disabled or ambulant control subjects. Although the clinical features of Friedreich's ataxia are similar to those associated with severe vitamin E deficiency, there are subtle but important clinical and neurophysiological differences between the two disorders.

Biochemical vitamin E deficiency in chronic pancreatitis

In order to study the frequency of biochemical vitamin E deficiency in chronic alcohol-induced pancreatitis, we measured plasma vitamin E and total blood lipids in 44 patients with chronic pancreatitis and 83 control subjects (44 normal controls; 39 Crohn's disease controls). Mean plasma vitamin E and mean ratio vitamin E/total blood lipids, a more sensitive indicator of vitamin E status, were significantly lower in chronic pancreatitis when compared with either control group. A low vitamin E/total lipids ratio was found in 75% of patients with pancreatitis. Within the chronic pancreatitis group, mean plasma vitamin E and the ratio vitamin E to total lipids were significantly lower in those with steatorrhoea (23 patients--pancreatic steatorrhoea subgroup) than in those without (21 patients--pancreatic non-steatorrhoea subgroup). 91% of the pancreatic steatorrhoea subgroup had a low vitamin E/total lipids ratio. However, patients without pancreatic steatorrhoea also had significantly lower levels of plasma vitamin E and the ratio vitamin E/total lipids when compared to controls. We conclude that biochemical vitamin E deficiency is common in chronic alcohol-induced pancreatitis, particularly in patients with steatorrhoea, and that factors other than fat malabsorption may be responsible for vitamin E deficiency in pancreatic non-steatorrhoea.

Effect of abnormal liver function on vitamin E status and supplementation in adults with cystic fibrosis

Patients with cystic fibrosis tend to have reduced serum concentrations of vitamin E and are therefore at risk of developing the neurological complications associated with vitamin E deficiency. Improved survival in cystic fibrosis has resulted in an increasing number of older patients who may develop hepatobiliary complications which may further impair the absorption of vitamin E. In this study the vitamin E status and results of supplementation with oral vitamin E were compared in adult patients with and without evidence of liver involvement as assessed by routine liver function tests. The serum vitamin E concentrations were reduced below normal in 24 of 25 patients. The mean serum vitamin E concentration was significantly lower (p less than 0.05) in those patients with abnormal liver function. When vitamin E status was assessed as the serum vitamin E/cholesterol ratio, however, there was no significant difference between those patients with normal and abnormal liver function. After supplementation with oral vitamin E, either 10 mg/kg/day for one month or 200 mg/day (equivalent to 3.4 to 4.4 mg/kg/day) for up to three months, there was no significant difference in the vitamin E status between the two groups. The results of this study indicate that in general, patients with cystic fibrosis and abnormal liver function do not require increased supplements of vitamin E compared with those with normal liver function.

Oral vitamin E supplements can prevent the retinopathy of abetalipoproteinaemia

Six patients with abetalipoproteinaemia are described who received large doses of oral vitamin E for between 12 and 18 years in addition to a low fat diet and supplements of the other fat soluble vitamins. The progressive retinopathy observed in untreated abetalipoproteinaemia was substantially modified and most probably prevented by this therapy. Angioid streaks were noted in one patient. Treatment with vitamin A alone did not prevent or arrest the progression of the retinal lesion.

Vitamin E--its role in neurological function

Studies in patients with abetalipoproteinaemia, other chronic and severe fat malabsorptive states and a selective defect in vitamin E absorption, together with neuropathological studies in the vitamin E deficient human, monkey and rat indicate that vitamin E is important for normal neurological function. Appropriate vitamin E supplementation is, therefore, advisable for all patients with chronic fat malabsorption who have low serum vitamin E concentrations. Serum vitamin E concentrations should also be measured in patients with spinocerebellar disorders, whatever the aetiology.

Vitamin E sufficiency in children with cholestasis: a comparison between erythrocyte peroxide hemolysis and serum alpha-tocopherol

Vitamin E sufficiency was assessed in 19 children with chronic cholestasis by determining both erythrocyte peroxide hemolysis (EPH) and serum alpha-tocopherol (alpha-T) levels. Eight had normal alpha-T (1.19 +/- 0.67 mg/dl; normal greater than 0.5). The mean EPH in this group was 13.1 +/- 14.3% (normal less than 20%). The remaining 11 patients had low alpha-T levels (0.25 +/- 0.15 mg/dl) and elevated EPH (83.9 +/- 17.1%). Children found to be vitamin E deficient received either oral alpha-T (50-100 IU/kg per day) or parenteral alpha-tocopherol acetate in sesame oil every 2-4 wk (200-300 mg). This permitted serial monitoring of EPH and alpha-T. We found that normalization of the EPH was uniformly accompanied by normalization of the alpha-T level. However, normal alpha-T levels occurred with elevated EPH (between 20% and 80%) on 11 occasions. EPH greater than 80% correctly identified vitamin E deficiency in all cases. Hence, EPH is a satisfactory screening test of vitamin E sufficiently. When the EPH is less than 20%, the patient is vitamin E sufficient. Conversely, when the EPH is greater than 80%, the patient is vitamin E deficient. Serum alpha-T measurements are needed to determine vitamin E sufficiency when the EPH is greater than 20% and less than 80%.

A study of the relationship between neurological function and serum vitamin E concentrations in patients with cystic fibrosis

A patient with cystic fibrosis and undetectable serum vitamin E concentrations is described who developed a progressive spinocerebellar syndrome and pigmentary retinopathy with abnormal somatosensory and visual evoked potentials (SSEPs and VEPs). In order to assess the relationship between neurological function and serum vitamin E concentrations in cystic fibrosis, 29 unselected patients who had no neurological symptoms were examined neurologically. Ten were randomly selected for neurophysiological assessment by recording SSEPs and VEPs. Electroretinograms (ERGs) were also performed in five cases. The findings were correlated with serum vitamin E concentrations which were unknown to the neurological investigators prior to completion of the study. Only one patient had definite reflex and sensory abnormalities, and the remaining 28 were clinically normal. The ERG was abnormal in two cases, one of whom had abnormal VEPs. SSEPs were normal in all 10 cases. Twenty six patients had serum vitamin E concentrations below the normal range. In two of the three patients who had definite neurological or electrophysiological abnormalities serum vitamin E concentrations were below the median value for the whole group.

Selenium deficiency and possible increased risk of carcinoma in adults with cystic fibrosis

20 young adults with cystic fibrosis (CF), including 2 with cancer, were found to have low serum selenium concentrations. Serum vitamin E concentrations were also low. It is suggested that low levels of circulating selenium are associated with increased risk of carcinoma, particularly in the presence of reduced vitamin E levels. Older patients with CF may be at increased risk for the development of carcinoma.

The role of vitamin E in the treatment of the neurological features of abetalipoproteinaemia and other disorders of fat absorption

Studies in patients with abetalipoproteinaemia and other chronic and severe fat malabsorptive states, and neuropathological studies in the vitamin E-deficient human, monkey and rat indicate that vitamin E is important for normal neurological function. Appropriate vitamin E supplementation is, therefore, advisable for all patients with chronic fat malabsorption who have low serum vitamin E concentrations.

Management of paucity of interlobular bile ducts

Two types of paucity of interlobular bile ducts (PIBD) may be observed in children with chronic cholestasis. The syndromatic type (80 cases) is the most frequent. The non-syndromatic type (32 cases) is the most severe and half of the patients in this group died from liver failure in the first years of life. The main therapeutic point is that patients with PIBD should not be operated on. The only treatment available is symptomatic medical treatment: the main helpful possibilities concern feeding of medium-chain triglycerides, large supplementation of liposoluble vitamins (A, D, E and K) given intramuscularly, phenobarbital and cholestyramine when there is severe pruritus. The place of the liver transplantation will be clarified in the near future.

Effect of dietary vitamin E on nitrite-treated rats

The effect of dietary vitamin E on cellular responses to nitrite was studied in rats. One-month-old male Sprague-Dawley rats were fed a basal vitamin E-deficient diet with or without 100 ppm vitamin E and 1000 ppm sodium nitrite (NaNO2) for 9 weeks. In addition to a high mortality rate, nitrite-fed rats maintained on a vitamin E-deficient diet exhibited a marked increase in liver necrosis, tubular nephrosis and myodegeneration, as well as greater biochemical and hematological alterations when compared to the control animals. No animal mortality or histopathologic lesions in any tissues were observed in rats receiving a vitamin E-supplemented diet with or without nitrite. The results suggest that depletion of vitamin E renders rats more susceptible to the adverse effect of nitrite, and that nitrite administration potentiates deficiency of vitamin E in rats.

Vitamin E and neurological function: abetalipoproteinaemia and other disorders of fat absorption

Evidence that vitamin E is important for normal neurological function in humans is presented. First, in abetalipoproteinaemia early therapy with vitamin E delays and may prevent the development of the neurological complications, and in patients with established lesions treatment can arrest or reverse the neuropathy. Second, in other chronic disorders of fat absorption with severe vitamin E deficiency, neurological manifestations which are very similar to those described in untreated abetalipoproteinaemia can be improved by vitamin E. Vitamin E supplementation is therefore advisable for all patients with chronic fat malabsorption who have low serum vitamin E concentration. Serum vitamin E concentrations should also be measured in patients with spinocerebellar disorders, whatever the aetiology.

Nervous and ocular disorders in children with cholestasis and vitamin A and E deficiencies

Thirteen children, aged 10 months to 20 years, presenting with chronic cholestasis from the first month of life and with low serum levels of vitamins A and/or E, have been investigated for neurological and ophthalmological symptoms. Clinical findings consisted of 4 types: peripheral neuropathy; cerebellar dysfunction; abnormalities of eye movement, and retinal degenerative changes. The results of electrophysiological and morphological studies of muscle and nerves were consistent with neurono-axonal degeneration. Electrical abnormalities of the retina, especially a decrease of the b wave of electroretinogram, appear to be the first sign of the syndrome, allowing early detection. Evidence for vitamin deficiency (E or E+A) suggests substitutive parenteral treatment in such patients.

Vitamin E and neurological function

Three lines of evidence indicate that vitamin E is important for normal neurological function in man. First, in abetalipoproteinaemia early therapy with vitamin E delays, and may prevent, the development of neurological complications, and in patients with established lesions treatment can arrest or reverse the neuropathy. Secondly, in other chronic disorders of fat absorption with severe vitamin E deficiency, neurological manifestations can be improved by vitamin E. Thirdly, the neuropathological changes observed in vitamin-E-deficient states in man (such as abetalipoproteinaemia, chronic liver disease, and cystic fibrosis) are similar to those reported in vitamin-E-deficient rats and monkeys.

Spinocerebellar degeneration secondary to chronic intestinal malabsorption: a vitamin E deficiency syndrome

Two adults are described who developed a progressive neurological disorder more than 20 years after the onset of chronic fat malabsorption. The clinical features included dysarthria, cerebellar ataxia, and prominent proprioceptive loss with depressed or absent tendon reflexes. Serum vitamin E was undetectable in both cases. One patient improved clinically and electrophysiologically after oral therapy with vitamin E. The findings in these patients were similar to those in others recently reported with vitamin E deficiency associated with biliary atresia. Electrophysiological observations suggested that the human deficiency state parallels that found neuropathologically in vitamin E-deficient animals.

Progressive neuromuscular disease in children with chronic cholestasis and vitamin E deficiency: clinical and muscle biopsy findings and treatment with alpha-tocopherol

We have studied four children (ages 6 to 17 years) with chronic cholestasis who developed a slowly progressive neuromuscular disease characterized by ataxia, dysmetria, areflexia, loss of vibratory sensation, and a variable ophthalmoplegia. Serum vitamin E concentrations were low in all patients prior to treatment (0.17-2.0 mg/g cholesterol, normal greater than 3 mg/g). Muscle histochemical studies showed prominent yellow autofluorescence, basophilic cytoplasmic inclusions which stain with esterase and acid phosphatase, and occasional necrotic fibers. Ultrastructural findings consisted of increased number and size of membrane-bound dense bodies (lysosomes), membranous whorls, and autophagic vacuoles. Intramuscular injections of all-rac-alpha-tocopherol (0.55-1.42 mg/kg per 24 hours based on individualized pharmacokinetic data) were required in three patients to achieve normal serum vitamin E values. High-dose (32 mg/kg per 24 hours) oral supplementation was effective in one patient. After normalization of serum vitamin E concentrations for 12 to 20 months, the neurologic disease has improved in all four patients.