Ratio Of Alpha-tocopherol Research Articles

Prevalence of vitamin E inadequacy, dietary intake and sources of alpha-tocopherol, and predictors of alpha- and gamma-tocopherol status in adolescent girls in Central Mozambique.

An adequate alpha-tocopherol status is important for females at reproductive age. We studied the dietary intake and sources of alpha-tocopherol and alpha- and gamma-tocopherol status indicators in 14-19-year-old girls in Central Mozambique. We also explored factors associated with alpha- and gamma-tocopherol status. The participants (n 508) were from the cross-sectional ZANE Study that was conducted in 2010. We recruited two separate samples, one in January-February and the other in May-June. We collected venous blood samples and conducted 24 h dietary recall interviews. At the time of blood sampling, 11% of participants were pregnant and 10% were lactating. In the total sample, both seasons combined, the median intake of alpha-tocopherol was 6⋅7 mg/d, the mean plasma alpha- and gamma-tocopherol concentrations were 13⋅5 and 0⋅75 μmol/l, respectively, and the prevalence of vitamin E inadequacy (alpha-tocopherol <12 μmol/l) was 36⋅7% (95% CI: 31⋅9-42⋅0%). Season and lactation status were significant predictors of alpha-tocopherol status regardless of which the three indicators (plasma concentration, alpha-tocopherol:total cholesterol ratio, gamma-tocopherol:alpha-tocopherol ratio) were used. Being a lactating mother was negatively associated and having a blood sample taken in January-February, when the main sources of alpha-tocopherol were mango and dark green leafy vegetables, was positively associated with alpha-tocopherol status. In conclusion, vitamin E inadequacy was common in Central Mozambique, and the status may fluctuate due to seasonal changes in the diet. We suggest that lactating mothers are specifically at risk of poor alpha-tocopherol status in resource-poor settings.

Silage Additives Usage in Improving Fermentation Quality of Alfalfa Silage: A Review

Alfalfa is difficult to ensile due to its high protein content, low water-soluble carbohydrate level, low dry matter content, and high buffering capacity. Therefore, alfalfa has recently increased its efforts to make silage with additives. Silage additives have been used to enhancing the silage quality of alfalfa in recent years. This review covers research studies that have investigated the efficacy of silage additives on fermentation quality, the bacterial diversity of alfalfa silage using the Next-Generation Sequencing (NGS) technique, the effects of microbial inoculant on these bacterial communities, silage's antioxidant enzymes, and unsaturated fatty acid levels. In recent studies, more clear information about bacterial communities in silage fermentation has begun to be obtained with the use of NGS technique. In studies using these techniques, it was reported that lactic acid bacteria (LAB) organic acid additions to alfalfa silage caused Lactobacillus, Pediococcus and Sporolactobacillus species to increase relatively in silage environment, the ratio of unwanted species decreased and silage quality increased. Although the amount of alpha-tocopherol, and beta carotene decreased by half in pure silage compared to fresh alfalfa, it was observed that LAB inoculation increased the ratio of alpha tocopherol, beta carotene and also polyunsaturated fatty acids. Future silage additives are expected to determine effects fermentation quality, the bacterial community, the antioxidant enzymes, and unsaturated fatty acid levels.

A study on gender related differences in oxidative stress status

Female lives longer than male and incidence of cardiovascular disease is lower in young female. However the role of oxidative stress has been repeatedly described in various diseases but rarely healthy people. The objective of the study was to observe the gender related differences in oxidative stress status and to show significance in alteration. This cross sectional and comparative study was carried out in the Department of Physiology, Rajshahi Medical College during the period from January 2013 to June 2014. Total 45 healthy adult subjects (25 males and 20 females) were enrolled in the study. Systematic sampling technique was used to select each study subject from students, doctors and staffs of Rajshahi Medical College. Malondialdehyde (MDA), a lipid peroxide and alpha-tocopherol, an antioxidant in plasma was measured. MDA:alpha-tocopherol ratio was used as a reliable marker of oxidative stress status. The mean plasma alpha-tocopherol concentration was significantly higher (p &lt; 0.05) and plasma MDA: alpha-tocopherol ratio was significantly lower (p &lt; 0.05) in female group than male group. The mean plasma alpha-tocopherol concentration was significantly higher (p &lt; 0.05) in female group aged 18-21 years than the corresponding male group. From the results of this study, it can be concluded that oxidative stress is less in female than in male indicating presence of potent compensatory response against oxidative stress in female which may be attributed to influence of female sex hormones.&#x0D; Mediscope Vol. 6, No. 1: Jan 2019, Page 13-18

The effect of a very high daily plant stanol ester intake on serum lipids, carotenoids, and fat-soluble vitamins

Intake of 2-3 g/d of plant stanols as esters lowers LDL cholesterol level, but there is no information about the efficacy and safety of a respective very high daily intake. We studied the effects of 8.8 g/d of plant stanols as esters on serum lipids and safety variables in subjects with mild to moderate hypercholesterolemia. In a randomized, double-blind, placebo-controlled study the intervention (n=25) and control (n=24) groups consumed spread and drink enriched or not with plant stanol esters for 10 weeks. Plant stanols reduced serum total and LDL cholesterol concentrations by 12.8 and 17.3% from baseline and by 12.0 and 17.1% from controls (P<0.01 for all). Liver enzymes, markers of hemolysis, and blood cells were unchanged. Serum vitamins A, D, and gamma-tocopherol concentrations, and the ratios of alpha-tocopherol to cholesterol were unchanged. Serum beta-carotene concentrations decreased significantly from baseline and were different from controls even when adjusted for cholesterol. Serum alpha-carotene concentration and alpha-carotene/cholesterol ratio were not different from controls. High intake of plant stanols reduced LDL cholesterol values without any other side effects than reduction of serum beta-carotene concentration. However, the end product, serum vitamin A levels, were unchanged. The results suggest that plant stanol ester intake can be increased to induce a greater cholesterol lowering effect.

A prospective study of pregnancy outcome and biomarkers of oxidative stress in nulliparous obese women

We sought to investigate pregnancy outcome and biomarkers of oxidative stress in nulliparous obese pregnant women. Pregnancy outcome and blood biomarkers were assessed prospectively in 385 obese nulliparous women from the placebo arm of a randomized controlled trial. Body mass index was associated with higher rates of preeclampsia (PE) (P = .010) and cesarean section (P = .016). In all, 18.8% of infants were small for gestational age (< 10th adjusted birthweight centile), 13.4% were large for gestational age (> 90th centile), and 11.9% were preterm. The plasma ascorbic acid concentration was inversely related to small-for-gestational-age delivery (P < .025), and increased plasma triglyceride concentrations with later PE (P < .0001). Plasma uric acid concentration (P = .043) and the gamma- tocopherol:alpha-tocopherol ratio (P = .023) were related to body mass index. A previously unreported risk of fetal growth restriction associated with reduced plasma ascorbic acid concentration was identified in nulliparous obese women. The high incidence of PE and preterm birth were unrelated to oxidative stress markers.

Distribution of serum concentrations of α-tocopherol and γ-tocopherol in the US population 1–3

Although the population distribution of serum concentrations of alpha-tocopherol has been described in the United States, little is known about the distribution of gamma-tocopherol or the ratio of alpha-tocopherol to gamma-tocopherol. Our aim was to describe the distribution of serum concentrations of alpha-tocopherol and gamma-tocopherol in a nationally representative sample of US adults. We reviewed data from 4087 adults aged >/=20 y who participated in the National Health and Nutrition Examination Survey (1999-2000). Concentrations of alpha-tocopherol and gamma-tocopherol were measured by using HPLC with ultraviolet-visible wavelength detection. The arithmetic mean (+/-SEM) of serum concentrations of alpha-tocopherol was 30.09 +/- 0.45 micromol/L, the median was 25.94 micromol/L, and the geometric mean (+/-SEM) was 27.39 +/- 0.38 micromol/L. The arithmetic mean of serum concentrations of gamma-tocopherol was 5.74 +/- 0.22 micromol/L, the median was 5.25 micromol/L, and the geometric mean was 4.79 +/- 0.18 micromol/L. The median ratio of alpha-tocopherol to total cholesterol was 4.93 micromol/mmol, that of gamma-tocopherol to total cholesterol was 1.03 micromol/mmol, and that of alpha-tocopherol to gamma-tocopherol was 4.53 micromol/mmol. Concentrations of alpha-tocopherol increased significantly (P for trend < 0.001) with age and were significantly (P = 0.015) lower in men than in women. African Americans and Mexican Americans had significantly (P < 0.001) lower concentrations of alpha-tocopherol than did whites. The median concentrations of gamma-tocopherol showed a trend with respect to age, did not differ significantly between men and women, and were slightly but nonsignificantly lower in white participants than in African American or Mexican American participants. Sociodemographic variations in serum concentrations of alpha-tocopherol and gamma-tocopherol exist among US adults.

Gamma-tocopherol as a possible marker for nutrition-related risk: results from four National Diet and Nutrition Surveys in Britain.

Relationships between vitamin E status (alpha and gamma-tocopherol and their ratio in plasma), anthropometric and biochemical indices, and food and nutrient intakes, were studied in four British National Diet and Nutrition Surveys: children aged 1.5-4.5 years, young people aged 4.0-18.0 years, adults 19.0-64.0 years and adults aged > or = 65.0 years. gamma-Tocopherol:alpha-tocopherol ratio declined with age. In older women gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratios were directly related to indices of obesity. In young men alpha- and gamma-tocopherols were directly correlated with obesity, but gamma-tocopherol:alpha-tocopherol ratio was not. For young people and toddlers, fewer obesity indices were available and relationships were weaker. Other fat- and water-soluble vitamin indices correlated directly with alpha-tocopherol and inversely with gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratio. Whereas alpha-tocopherol correlated directly with 'healthy' nutrient choices (such as intrinsic sugars, dietary fibre, vitamins and potassium) and inversely with 'unhealthy' choices (extrinsic sugars and monounsaturated fats, i.e. avoidance of polyunsaturated fat), gamma-tocopherol and the gamma-tocopherol:alpha-tocopherol ratio related inversely with 'healthy' choices. Food groups had analogous relationships; thus, alpha-tocopherol related directly to use of polyunsaturated fats, fresh fruits and fruit juices, and inversely to non-polyunsaturated fats and extrinsic sugar. The reverse was true for gamma-tocopherol and gamma-tocopherol:alpha-tocopherol ratio. Although the mechanisms underlying these relationships are obscure, the gamma-tocopherol:alpha-tocopherol ratio may reveal poor dietary choices, status predictors and a propensity for obesity in later life, especially in women.

Platelet phospholipids are differentially protected against oxidative degradation by plasmalogens.

The oxidative degradation of phospholipids in the presence and absence of plasmalogens (plasmenyl phosphatidylethanolamine: PPE) was followed by chemical analysis. Human platelet phospholipids, either intact or after removal of PPE by acid treatment, were oxidized with 28 mM 2,2'-azobis(2-amidinopropane di-HCl in Triton X-100 micelles (detergent/phospholipid 5:1, mol/mol). PPE (12% of all phospholipids, mol/mol) disappeared about three times more rapidly than glycerophospholipids, whereas sphingomyelin remained unaltered and the lysophosphatidylethanolamine (lysoPE) generated became progressively more unsaturated. After 60 min oxidation, the FA compositions of PS, PC, and PI were similar in extracts with or without plasmalogens. In contrast, diacyl phosphatidylethanolamine (DPE) became more saturated in the absence of PPE. The rate of phospholipid destruction was always unique to each class, but for all phospholipids slowed down in the presence of PPE. This protective effect increased in the order DPE < PS < PC < PI and did not seem to be simply related to the class unsaturation. Alpha-tocopherol had no influence on the time courses of the quantities and compositions of the phospholipids, even at a molar ratio of alpha-tocopherol to phospholipids four times higher than in platelet membranes. Thus, PPE protected phospholipids efficiently but differentially against peroxidative attack, whereas the contribution of alpha-tocopherol appeared to be negligible even at a concentration four times greater than in platelet membranes.

Tissue distribution of alpha-tocopherol in nephrotic rats.

1. Reactive oxygen species are involved in the pathogenesis of puromycin aminonucleoside (PAN) nephrosis and alpha-tocopherol is one of the major anti-oxidants in the body. 2. In the present study, we measured the levels of alpha-tocopherol by high-performance liquid chromatography in the plasma and in nine tissues of control and nephrotic rats obtained 10 days after either 0.9% saline solution or PAN injection, respectively. 3. In nephrotic rats, alpha-tocopherol levels increased four-fold in plasma; however, the molar ratio of alpha-tocopherol/ cholesterol remained unchanged, suggesting that the increase in alpha-tocopherol content was attributable to an increase in plasma lipid concentration. 4. In nephrotic rats, the alpha-tocopherol/cholesterol ratio increased 1.33-fold in adrenal glands and 1.34-fold in the testis, but remained unchanged in heart, spleen, liver, kidney lung, brain and muscle. 5. These data suggest that, in PAN nephrotic rats, there are alterations in the distribution of alpha-tocopherol and there is no deficiency of alpha-tocopherol in plasma or tissues.

Cerebrospinal fluid levels of alpha-tocopherol in amyotrophic lateral sclerosis.

We compared CSF and serum levels, and the CSF/serum ratio of alpha-tocopherol (vitamin E), measured by HPLC, in 30 patients with sporadic amyotrophic lateral sclerosis (SALS) and 78 matched controls. The mean CSF and serum vitamin E levels did not differ significantly between the 2 study groups. These values were not influenced by the clinical form (spinal versus bulbar) of SALS. CSF alpha-tocopherol levels did not correlate with age, age at onset, and duration of the disease. These results suggest that CSF and serum alpha-tocopherol concentrations are unrelated with the risk for ALS.

Cerebrospinal fluid levels of alpha-tocopherol in patients with multiple sclerosis

We compared cerebrospinal fluid (CSF) and serum levels, and the CSF/serum ratio of alpha-tocopherol (vitamin E), measured by HPLC, in 36 patients with multiple sclerosis (MS) and 32 matched controls. The mean CSF vitamin E levels and the CSF/serum vitamin E ratio did not differ significantly between the two study groups. The serum levels of vitamin E and the serum vitamin E/cholesterol ratio were significantly lower in MS patients when compared with controls ( P<0.05 and P<0.01, respectively). These values were not correlated with age, age at onset and duration of the disease in the patients group. These results suggest that CSF vitamin E concentrations are not a marker of activity of MS activity.

Vitamin A and vitamin E statuses of preschool children of socioeconomically disadvantaged families living in the midwestern United States.

To determine the vitamin A and vitamin E statuses of socioeconomically disadvantaged preschool American children. Cross-sectional study of preschool children from socioeconomically disadvantaged families. Central Iowa, USA. A group of 77 apparently healthy children was studied with the following characteristics: 5 mo-6 y; 37 males, 40 females, 56 non-Hispanic Caucasians, 3 Hispanics, 18 Afro-Americans. Modified relative dose response (MRDR) test for vitamin A status assessment; serum retinol, alpha-tocopherol, cholesterol, and carotenoids; weight for age. Although the mean weight for age was the 53rd percentile of the NCHS standard, a significant number of children (P = 0.006, chi(2)) were either markedly underweight or overweight. Ratios of 3,4-didehydroretinol to retinol (DR/R) were > 0.030, in 32% of the children. Mean serum retinol, alpha-tocopherol and cholesterol (+/- s.d.) were 1.09 +/- 0.23 microM/L, 16.8 +/- 6.3 microM/L and 4.01 +/- 0.8 microM/L. Three children (3.9%) showed a serum retinol value < 0.7 microM/L. One child with a serum retinol value < 0.7 microM/L and one additional child showed a ratio of alpha-tocopherol to cholesterol < 1.44 mumol/mmol. The mean alpha-tocopherol to cholesterol ratio for the group (4.31 +/- 1.71 mumol/mmol), however, was satisfactory. The only significant (P < or = 0.05) age-related changes were an increase in the serum cholesterol (P = 0.005) and decrease in the alpha-tocopherol to cholesterol ratio (P < 0.005) between the 0-2 y and the 2-4 y groups. Serum cholesterol (P = 0.0165, two-tailed) and lycopene (P = 0.004) concentrations of Afro-Americans were significantly higher than those of Caucasians. Median serum concentrations of alpha-carotene and beta-carotene were lower and, of lycopene higher than those found in children studied in a national survey. Serum carotenoid concentrations generally increased with age. Larger percentages of underweight and overweight children and a significant degree (32%) of inadequate vitamin A status were found in this group of socioeconomically disadvantaged children. Afro-Americans showed higher serum cholesterol and lycopene concentrations than did Caucasians, but otherwise were nutritionally similar. Age-related changes were small. Of nutritional parameters considered, the vitamin A status of socioeconomically disadvantaged segments of our population clearly needs attention.

Assessment of hepatic vitamin E status in adult patients with liver disease.

No published reports compare hepatic alpha-tocopherol (adjusted for hepatic lipid content) with indicators of blood alpha-tocopherol in adult patients with various liver diseases. alpha-Tocopherol was simultaneously measured in liver biopsy tissues and blood from 66 subjects (9 comparison patients hospitalized for biliary tract surgery, 13 with chronic persistent hepatitis, 9 with chronic aggressive hepatitis, 10 with acute hepatitis, 10 with cirrhosis, 7 with both cirrhosis and hepatic cell carcinoma, and 8 with fatty liver). Hepatic, erythrocyte, and plasma alpha-tocopherol concentrations were measured, as were hepatic and serum lipids. The ratios of alpha-tocopherol to total lipid concentrations (Toc/TL ratios) in plasma and liver were calculated. In both comparison patients and patients with chronic persistent hepatitis and fatty liver, hepatic alpha-tocopherol concentrations were strongly correlated with hepatic triglyceride and total lipid concentrations (r = .72, P < .001; and r = .75, P < .001, respectively); the relationships (slopes) when hepatic alpha-tocopherol concentrations were compared with hepatic triglyceride and total lipid concentrations were similar in these patients and in all subjects. No strong correlations were found between hepatic and blood alpha-tocopherol parameters in all subjects. These results suggest that hepatic alpha-tocopherol is present at similar concentrations in triglycerides as well as total cholesterol and phospholipids and that neither plasma Toc/TL ratios nor erythrocyte alpha-tocopherol concentrations are useful indicators of hepatic vitamin E status. The hepatic Toc/TL ratio may be useful to assess total hepatic vitamin E status.

Cerebrospinal fluid levels of alpha-tocopherol (vitamin E) in Alzheimer's disease.

We compared CSF and serum levels, and the CST/serum ratio of alpha-tocopherol (vitamin E), measured by HPLC, in 44 apparently well-nourished patients with Alzheimer's disease (AD) and 37 matched controls. CSF and serum vitamin E levels were correlated, both in AD patients and in controls. The mean CSF and serum vitamin E levels were significantly lower in AD patients, and the CSF/serum ratio of AD patients did not differ significantly between the 2 study groups. CSF vitamin E levels did not correlate with age, age at onset, duration of the disease and score of the Minimental State Examination in the AD group. Weight and body mass index were significantly lower in AD patients than in controls. These results suggest that low CSF and serum vitamin E concentrations in AD patients could be related with a deficiency of dietary intake of vitamin E.

Lipoproteins containing apolipoprotein B isolated from patients with abetalipoproteinemia and homozygous hypobetalipoproteinemia: identification and characterization

Abetalipoproteinemia (ABL) and homozygous hypobetalipoproteinemia (HBL) are inherited disorders which are classically characterized by progressive retinal and spinocerebellar disease, fat-soluble vitamin deficiency, and absence of apolipoprotein (apo) B from the plasma. Using immunoaffinity chromatography with an anti-apo B antiserum, we isolated apo B-containing lipoprotein (LpB) particles from the plasma of 4 ABL and 2 HBL patients. The LpB particles were characterized and compared with low density lipoprotein (LDL) and LpB isolated from normal plasma. The ABL HBL LpB particles were similar in size and charge to normal LpB particles but were relatively enriched in several other apolipoproteins. They contained alpha-tocopherol in a ratio to cholesterol that was proportionately much higher than the very low ratio of alpha-tocopherol to cholesterol in plasma. They bound saturably to fibroblasts and were internalized and degraded similarly to LDL. Hence, the molecular defects in ABL and HBL permit the secretion of a very small number of apo B-containing lipoproteins which may be important for transport of alpha-tocopherol to peripheral tissues.

Depletion of alpha-tocopherol in human atherosclerotic lesions.

Estimations of alpha-tocopherol content were made on a series of human necropsy samples of normal arterial wall and of atherosclerotic lesions. The results were compared with stage of lesion, shown by histology, and with the amounts of cholesterol and hydroxycholesterols in the same lesions. The ratio of alpha-tocopherol to cholesterol levels varied widely in normal arterial wall but was consistently low in lesions, especially in lesions rich in macrophage foam cells. The results suggested that significant accumulation of hydroxycholesterols, found almost exclusively in lesions, only occurred when alpha-tocopherol levels were low in relation to the cholesterol content. This suggests that oxidative activity in the lesion may lead to significant oxidation of constituents of low-density lipoprotein only after alpha-tocopherol has been depleted.

Radical-mediated oxidation of isolated human very-low-density lipoprotein.

Oxidative modification of human low-density lipoprotein (LDL) has received much attention because of its suggested involvement in the early events of atherogenesis. In contrast, little data exist concerning the oxidation of human very-low-density lipoprotein (VLDL), although such modification promotes foam cell formation by these lipoproteins. We therefore investigated the radical-mediated oxidation of VLDL by using controlled oxidizing conditions and sensitive and specific methods to assess lipoprotein lipid oxidation and antioxidation. We observed that the ratio of alpha-tocopherol to coenzyme Q10 in VLDL was close to that of LDL, suggesting that these lipoproteins may transport some coenzyme Q10 to extrahepatic tissues, as they do tocopherol. Most of the coenzyme Q10 associated with VLDL was present in its reduced, antioxidant active form, ubiquinol-10. The small amounts of ubiquinol-10 in VLDL provided the lipoprotein lipids with a highly efficient antioxidant protection. Also, the kinetics of radical-mediated lipid peroxidation in VLDL resembled that in LDL and therefore also probably proceeded via the recently described tocopherol-mediated peroxidation mechanism. Oxidation competition experiments using aqueous radicals and physiological concentrations and molar ratios of LDL and VLDL indicated that in contrast to the situation with high-density lipoproteins, lipid peroxidation was initiated and detected simultaneously in the former two lipoprotein particles. However, once initiated, peroxidation propagated at an approximately twofold higher rate in VLDL than LDL. Our studies suggest that radical-mediated lipid (per)oxidation proceeds via similar mechanisms in isolated LDL and VLDL. We conclude that efficient LDL antioxidants are also likely to be effective protective agents for VLDL.

Influence of Maternal Factors on Cord and Neonatal Plasma Micronutrient Levels

The influence of gestational length, maternal prenatal supplement and maternal levels on umbilical cord and neonatal plasma selenium, alpha-tocopherol, and retinol were studied and appropriate reference intervals for ongoing studies of gestational and perinatal micronutrient requirements were derived. We measured retinol, alpha-tocopherol (total and alpha-tocopherol:cholesterol ratio), selenium, and glutathione peroxidase in 160 umbilical cord samples and 58 paired maternal and neonatal samples collected on the third postpartum day. Selenium and glutathione peroxidase were also measured in 25 paired umbilical artery and vein samples. The strongest correlation with gestational age and birthweight was found for the cord blood variables, whereas levels in maternal blood were not related to either gestation or weight. Neonatal values were significantly lower than maternal for selenium (0.96 [0.25] compared with 1.56 [0.27] mumol/liter), retinol (0.54 [0.19] and 1.26 [0.45] mumol/liter), alpha-tocopherol (11.5 [3.63] and 32.4 [9.20] mumol/liter), and glutathione peroxidase (446 [174] and 873 [176] U/liter) but not for the ratio of alpha-tocopherol:cholesterol (5.0 compared with 6.0). Maternal use of tocopherol and retinol supplements did not significantly affect blood concentrations. Maternal plasma selenium levels at term were about 60% of nonpregnant adult females. Selenium concentration and glutathione peroxidase activity did not differ between paired umbilical cord arterial and venous samples. Selenium, retinol, and glutathione peroxidase differed between infants born before or after 37 weeks' gestation.

Serum alpha-tocopherol levels of Mexican Americans, Cubans, and Puerto Ricans aged 4–74 y

Data from the Hispanic Health and Nutrition Examination Survey were used to examine serum alpha-tocopherol levels (in subjects aged 4-74 y) and ratios of alpha-tocopherol to cholesterol plus triglyceride and to cholesterol (in subjects aged 20-74 y) of Mexican Americans (MA), Cubans, and Puerto Ricans (PR). Neither alpha-tocopherol nor the alpha-tocopherol-lipid ratios differed between sexes. PR had lower mean alpha-tocopherol and alpha-tocopherol-lipid ratios and higher prevalences of alpha-tocopherol less than 11.6 mumol/L than did MA or Cubans in several age groups. MA and Cuban adolescents had lower alpha-tocopherol levels than children had. Mean alpha-tocopherol levels and alpha-tocopherol-lipid ratios increased and prevalences of alpha-tocopherol less than 11.6 mumol/L decreased during adulthood in all three ethnic groups.

The role of vitamin E in the nutrition of premature infants

Vitamin E (alpha-tocopherol) has been credited with a variety of beneficial effects in the premature newborn infant. It has been thought that deficiency of vitamin E is at least partly responsible for the anemia which often occurs 4 to 6 wk after premature birth, and routine dietary supplementation with vitamin E is frequently recommended. However, critical analysis reveals that published controlled studies of vitamin E supplementation do not agree on the magnitude or even the existence of this protective effect against anemia. Analysis of commonly used feeding practices suggests that the dietary ratio of alpha-tocopherol to polyunsaturated fatty acids is generally sufficient to prevent manifestations of vitamin E deficiency without supplementation. Large parenteral doses of vitamin E have been purported to protect premature infants exposed to oxygen-enriched environments and mechanical ventilation from the complications of retrolental fibroplasia and bronchopulmonary dysplasia. Subsequent studies, however, have not yet substantiated encouraging early reports of these protective effects. At present, there seems to be no clearly established need for supplementing the premature infant's usual dietary intake of vitamin E.