Blood Selenium Concentrations Research Articles

Selen in der Tumorprävention

Krebs ist eine der wichtigsten Todesursachen in den Industrieländern, und daher wurde in den letzten Jahren über Präventionsmöglichkeiten diskutiert, z.B. die Anwendung von Selenpräparaten. Beginnend mit den siebziger Jahren des letzten Jahrhunderts sind eine große Anzahl von Veröffentlichungen erschienen, die im Allgemeinen einen inversen Zusammenhang von Selenkonzentrationen im Vollblut oder Serum und dem Risiko für das Auftreten bestimmter Tumorerkrankungen belegen. Nachdem einige Interventionsstudien beim Menschen zur Krebsprävention durch Selen vielversprechende Resultate lieferten, wurde die so genannte SELECT-Studie aufgelegt, die bislang größte doppelblinde und placebokontrollierte Studie zur Prävention von Prostatakrebs. Der Beitrag gibt einen Überblick über die bislang publizierte Literatur.

Cadmium, Lead, and Selenium in Cord Blood and Thyroid Hormone Status of Newborns

Cadmium (Cd), lead (Pb), and selenium (Se) concentrations in cord whole blood, sampled from 24 women at the time of delivery in a hospital in Tokyo in 2005, were determined by inductively coupled plasma mass spectrometry with a reaction cell. Signal enhancement caused by nonspectroscopic interference for Se was evident and the standard addition technique was essential for correcting the interference. Median concentration in cord bloods was 0.20 ng/g, 6.7 ng/g (0.67 microg/dL), and 191 ng/g for Cd, Pb and Se, respectively. Lead concentration was lower, whereas Se concentration was higher, than those reported in other countries. The trace element concentration was related to the levels of thyroid stimulating hormone (TSH) and free thyroxin (fT4) in the neonatal blood sampled at 4-6 days postpartum. A significantly negative correlation was observed between Cd concentrations in cord blood and TSH concentration in neonatal blood. The result indicated the possible effect of in utero Cd exposure on thyroid hormone status of newborns and that Cd exposure level should be assessed as a covariate in the survey on the relationship between in utero chemicals (e.g., PCBs) exposure and thyroid hormone status.

Biological availability of selenosugars in rats

The biological availability and metabolism of two selenosugars orally administered to rats were investigated. Two other selenium species, selenite and trimethylselenonium ion (TMSe) were included in the study as positive and negative controls, respectively. Male Wistar strain rats (three per group) at 8 weeks of age were exposed to sodium selenite, TMSe, selenosugar 1 (methyl-2-acetamido-2-deoxy-1-seleno-β- d-galactopyranoside) or selenosugar 2 (methyl-2-acetamido-2-deoxy-1-seleno-β- d-glucopyranoside) through drinking water for 48 h. Total selenium concentrations (ICPMS) and selenium species concentrations (HPLC/ICPMS) were determined in urine samples collected in two 24 h periods during the exposure, and total selenium concentrations in liver, kidney, small intestine and blood were determined at the end of the experiment. The major species found in background urine were selenosugar 1 (major metabolite) and TMSe (minor metabolite). Rats exposed to selenite excreted large quantities of selenosugars and TMSe consistent with efficient uptake and biotransformation of selenite, whereas TMSe-exposed rats excreted large quantities of TMSe, but there was no significant increase of other selenium metabolites, consistent with TMSe being taken up and excreted unchanged. Rats exposed to selenosugars, however, excreted significant quantities of TMSe suggesting that the sugars were at least partly biologically available and biotransformed. Rats exposed to selenite accumulated selenium in the liver, kidney, small intestine and blood, whereas no accumulation was observed for the other samples except for small increases in selenium concentrations of small intestine from the two selenosugar-exposed groups.

Influence of Glucose in the Dialysate on the Activity of Erythrocyte-Glutathione-Peroxidase and Blood Selenium Concentration in Hemodialyzed Patients

The aim of the study was to show the influence of glucose in the dialysate on the intensity of oxidative stress, activity of glutathione peroxidase (GSHPx) and concentration of selenium in patients undergoing regular hemodialysis. The study was comprised of 85 patients hemodialyzed with dialysate containing glucose [HD-g(+)] or not containing glucose [HD-g(-)], patients with chronic renal failure on conservative treatment and control group. The concentrations of the products of reaction with thiobarbituric acid (TBARS), concentration of selenium in erythrocytes and plasma, concentration of copper in erythrocytes and the activity of GSHPx were determined. GSHPx had significantly higher activity in HD-g(-) group before HD than in control group. In HD-g(+) group before hemodialysis, the activity of GSHPx was significantly lower than in the control group. After HD, the activity showed a statistically significant increase. In both hemodialyzed groups, selenium concentration before hemodialysis both in plasma and erythrocytes was significantly lower, compared to control group. In the group of patients with CRF on conservative treatment, selenium concentration in RBC was significantly higher, compared to concentrations obtained in other groups except for control group. The increase of copper concentration in erythrocytes was accompanied by the increase of oxidative stress and increase of TBARS concentration. The opposite relationship was observed for selenium-its concentration was inversely correlated to copper concentration. In both groups of hemodialyzed patients, hemodialysis caused the increase of GSHPx in erythrocyte activity and increase of plasma and erythrocyte selenium concentration.

Selenium toxicokinetics after oral and intravenous administration in buffalo calves

The blood levels, toxicokinetics and urinary excretion of selenium were investigated in healthy male buffalo calves after single oral and intravenous administration of selenourea at the dose rate of 0.75 mg/kg (providing 0.48 mg/kg selenium). The concentration of selenium in blood and urine was estimated spectrophotometrically. Following administration of the drug, the blood selenium disposition patterns exhibited two distinct peaks. The toxicokinetic parameters of selenium were determined by employing non-compartmental analysis. The values of AUC, t 1/2 elm , Cl B and Vd SS were 18.46 μg ml −1 h, 10.33 h, 20.04 ml kg −1 h −1and 0.3 l kg −1, respectively, after oral administration and 23.97 μg ml −1 h, 7.12 h, 20.53 ml kg −1 h −1 and 0.2 l kg −1, respectively, following intravenous injection of selenourea. The value of MRT was higher after oral dosing. The bioavailability of selenium, following oral administration of selenourea was 77%. Approximately, 22% of the total intravenous dose and 5.9% of total oral dose of selenium was excreted in urine within 24 h of administration of selenourea. The data on blood Se levels may be of help in diagnosing the impeding selenium toxicosis and thus preventing mortality due to selenium toxicity.

Selenium in Intensive Care (SIC): Results of a prospective randomized, placebo-controlled, multiple-center study in patients with severe systemic inflammatory response syndrome, sepsis, and septic shock*

Sepsis is associated with an increase in reactive oxygen species and low endogenous antioxidative capacity. We postulated that high-dose supplementation of sodium-selenite would improve the outcome of patients with severe sepsis and septic shock. Prospective randomized, placebo-controlled, multiple-center trial. Eleven intensive care units in Germany. Patients were 249 patients with severe systemic inflammatory response syndrome, sepsis, and septic shock and an Acute Physiology and Chronic Health Evaluation (APACHE) III score >70. Patients received 1000 microg of sodium-selenite as a 30-min bolus injection, followed by 14 daily continuous infusions of 1000 microg intravenously, or placebo. The primary end point was 28-day mortality; secondary end points were survival time and clinical course of APACHE III and logistic organ dysfunction system scores. In addition, selenium levels in serum, whole blood, and urine as well as serum glutathione-peroxidase-3 activity were measured. From 249 patients included, 11 patients had to be excluded. The intention-to-treat analysis of the remaining 238 patients revealed a mortality rate of 50.0% in the placebo group and 39.7% in the selenium-treated group (p = .109; odds ratio, 0.66; confidence interval, 0.39-1.1). A further 49 patients had to be excluded before the final analysis because of severe violations of the study protocol. In the remaining 92 patients of the study group, the 28-day mortality rate was significantly reduced to 42.4% compared with 56.7% in 97 patients of the placebo group (p = .049, odds ratio, 0.56; confidence interval, 0.32-1.00). In predefined subgroup analyses, the mortality rate was significantly reduced in patients with septic shock with disseminated intravascular coagulation (n = 82, p = .018) as well as in the most critically ill patients with an APACHE III score > or =102 (>75% quartile, n = 54, p = .040) or in patients with more than three organ dysfunctions (n = 83, p = .039). Whole blood selenium concentrations and glutathione peroxidase-3 activity were within the upper normal range during selenium treatment, whereas they remained significantly low in the placebo group. There were no side effects observed due to high-dose sodium-selenite treatment. The adjuvant treatment of patients with high-dose sodium-selenite reduces mortality rate in patients with severe sepsis or septic shock.

Effect of soluble glass bolus administration on the blood selenium concentration in grazing Philippine goats under backyard conditions

ABSTRACTThe present study was conducted to determine the effects of selenium (Se) soluble glass bolus (SGB) on blood Se concentrations of mixed‐bred (native × Anglo Nubian) pregnant does weighing between 15 and 52 kg and grazing on natural pastures in the Philippines. The control group, consisting of 28 does, was not administered with SGB, while 23 does were administered with SGB every 6 months for a period of 12 months. Forage and blood samples in both groups were collected every 2 months. Their Se, sulfur, calcium, phosphorus, magnesium, copper and zinc concentrations were analyzed using the wet digestion method. The results showed that the grazed forage had concentrations of all these minerals that were far higher than the accepted critical lower levels. The Se concentration was higher (P < 0.05) in the dry season than in the rainy season, especially in the whole blood collected from the does and newborn kids. In both groups the Se concentration in the kids tended to increase during the suckling period but decreased after weaning. Kids born to the SGB does had higher whole blood Se concentrations (P < 0.05) than those born to the control does. However, the administration of SGB to the does did not affect any blood mineral concentrations except for Se in the grazing does and their kids. The animals did not exhibit any clinical signs of mineral deficiencies or toxicities during the experimental period.

Selenium absorption, distribution, and excretion in white sturgeon orally dosed with L‐selenomethionine

The usefulness of a newly developed, combined technique consisting of esophageal intubation, dorsal aortic cannulation, and urinary catheterization to deliver Se orally and to monitor Se uptake, accumulation, and excretion in white sturgeon (Acipenser transmontanus) was explored. Groups of five yearling sturgeon (1-2 kg) each were intubated with 0 (sham), 250, 500, or 1,000 microg Se/kg body weight in the form of L-selenomethionine, an ecologically relevant organic form of Se. Selenium concentrations in whole blood, plasma, and red blood cells did not change in the sham group but began to rise within 2 h postintubation in the other groups, and levels remained near maximum concentrations throughout the 48-h sampling period. Average urinary Se excretion rates over the entire 48-h period were 0.05, 0.46, 0.61, and 2.15 microg Se/kg/h in sturgeon intubated with 0, 250, 500, and 1,000 microg Se/kg, respectively. Selenium excretion rates were highest within the first 6 h in all treatment groups except the sham group. Selenium concentrations in the liver were positively correlated with the intubated Se dosage.

Selenium and coronary heart disease: a meta-analysis

It is hypothesized that low selenium concentrations are associated with an increased risk of cardiovascular disease and that selenium supplements prevent coronary heart disease. The objective was to perform a meta-analysis on the association of selenium biomarkers with coronary heart disease endpoints in observational studies and on the efficacy of selenium supplements in preventing coronary heart disease endpoints in randomized trials. The MEDLINE and the Cochrane Library databases were searched for studies conducted from 1966 through 2005. Relative risks were pooled by using an inverse-variance weighted random-effects model. Twenty-five observational studies (14 cohort and 11 case-control studies) that measured blood or toenail selenium concentrations and 6 randomized trials that evaluated supplements containing selenium met our inclusion criteria. The pooled relative risk in a comparison of the highest with the lowest selenium concentration categories was 0.85 (95% CI: 0.74, 0.99) in cohort studies and 0.43 (0.29, 0.66) in case-control studies. In observational studies, a 50% increase in selenium concentrations was associated with a 24% (7%, 38%) reduction in coronary heart disease risk. In randomized trials, the pooled relative risk in a comparison of supplements containing selenium with placebo was 0.89 (0.68, 1.17). Selenium concentrations were inversely associated with coronary heart disease risk in observational studies. Because observational studies have provided misleading evidence for other antioxidants, the validity of this association is uncertain. Few randomized trials have addressed the cardiovascular efficacy of selenium supplementation, and their findings are still inconclusive. Evidence from large ongoing trials is needed to establish low selenium concentrations as a cardiovascular disease risk factor. Currently, selenium supplements should not be recommended for cardiovascular disease prevention.

Whole blood mercury and selenium concentrations in a selected Austrian population: Does gender matter?

Data on mercury exposure of the Austrian population were inadequate. This study was performed to determine the causal factors underlying mercury exposure and selenium concentrations, and to estimate the gender-related health impacts. Venous blood samples of 78 women and 81 men were drawn at the Austrian Red Cross, Vienna. Mercury contents in acid-digested whole blood samples were measured after amalgam enrichment by CV-AAS, and selenium by AAS (heated quartz-cell) after hydrid formation. The average total mercury blood content of Austrians was low (2.38+/-1.55 microgL(-1); N=152). Mercury and selenium concentrations were not different between the genders (P>0.05) but we observed discrepancies regarding the causal factors. Mercury levels in men were influenced not only by fish consumption but also by age, education level, and amalgam fillings, whereas in women, only the diet (fish/seafood, red wine consumption) determined blood mercury (P<0.05). Moreover, only the males indicated a depressive effect of dental amalgam on hematocrit (P<0.05). Regarding selenium, age and alcohol consumption led to lower concentrations in men, whereas a high-level education had the opposite effect; no determinant was found for women. For the whole study group, a significant effect of chronic disease on selenium levels could be detected (P<0.05). 18% of women and 13% of men showed marginal selenium deficiency (blood selenium<65 microgL(-1)). Selenium and mercury concentrations were not correlated. Our results indicate the need to evaluate and integrate gender-related findings in metal toxicology and trace element research, because different causal factors require different preventive measures to reduce mercury exposure and the risk of low selenium concentrations. Future research is needed on the gender- and age-related differences in fish/seafood consumption habits, the modifications of mercury toxicokinetics through sex hormones, the selenium supply in Austria, and the clinical relevance of a low selenium status.

Selenium Supplementation of Lactating Dairy Cows: Effect on Selenium Concentration in Blood, Milk, Urine, and Feces

The objectives were to determine effects of graded levels of selenized yeast derived from a specific strain of Saccharomyces cerevisiae (CNCM I-3060) on animal performance and in selenium concentrations in the blood, milk, feces, and urine of dairy cows compared with sodium selenite; and to provide preliminary data on the proportion of selenium as selenomethionine in the milk and blood. Twenty Holstein cows were used in a 5×5 Latin square design study in which all cows received the same total mixed rations, which varied only in source or concentration of dietary selenium. There were 5 experimental treatments. Total dietary selenium of treatment 1, which received no added selenium, was 0.15 mg/kg of dry matter, whereas values for treatments 2, 3, and 4, derived from selenized yeast, were 0.27, 0.33, and 0.40 mg/kg of dry matter, respectively. Treatment 5 contained 0.25mg of selenium obtained from sodium selenite/kg of dry matter. There were no significant treatment effects on animal performance, and blood chemistry and hematology showed few treatment effects. Regression analysis noted significant positive linear effects of increasing dietary selenium derived from selenized yeast on selenium concentrations in the milk, blood, urine, and feces. In addition, milk selenium results indicated improved bioavailability of selenium from selenized yeast, compared with sodium selenite. Preliminary analyses showed that compared with sodium selenite, the use of selenized yeast increased the concentration of selenomethionine in the milk and blood. There was no indication of adverse effects on cow health associated with the use of selenized yeast.

Selen und Katarakt - Risikofaktor oder sinnvolle Nahrungsergänzung?

The exact role of selenium in cataract development is still unclear. Both protective and toxic effects and mechanisms have been postulated in the past. Accordingly, the selenium contents in human lenses and blood sera in different forms of cataract were investigated. 123 patients (76 female and 37 male) with a mean age of 69.8 years (range: 17 to 91 years) were enrolled in this study. Overall, 84 lenses (after ECCE) and 110 blood serum samples were investigated by atomic absorption spectroscopy. Interpretation of data was accompanied by exact preoperative investigations including Scheimpflug techniques. A significant increase of selenium content of the lenses was found with increasing lens opacification and colouration. Lenses with a mature cataract showed the highest selenium contents in the lens compared to other cataract forms. Opposite results were detected in blood serum. Lenses of diabetics showed already at a younger age changes in selenium content. Smokers showed both decreased selenium contents in the lens and decreased selenium concentration in blood serum. An obvious correlation between the type of cataract and selenium content of the lens seems to exist. The question by which mechanism selenium acts directly or by selenium-dependent enzymes acts lens opacification remains speculative up to now.

Study of Blood Selenium Level in Thyroid Pathologies by Instrumental Neutron Activation Analysis

Selenium deficiency constitutes a risk factor for several pathologies (congestive cardiomyopathie, cancer, etc.). It was shown, recently, that selenium is implied in thyroid metabolism. It constitutes the catalytic site of the enzymes intervening in thyroid hormone synthesis. In the present work, we determined concentrations of selenium in total blood of 39 patients suffering from thyroid pathologies (hyperthyroidism [HEP], hypothyrodism [HOP], simple goiter [SG]), and 29 normal controls using instrumental neutron activation analysis (INAA). The blood selenium concentrations of patients suffering from hyperthyroidism was 142.56±20.25 µg/L of total blood, which is significantly lower than that of normal controls (206.72±17.98 µg/L. p≤0.05). No significant differences were observed in the concentrations of Se in hypothyroidism (184.26±20.77 µg/L) and simple goiter groups (160.47±25.76 µg/L).

Effects of Spent Composts of Selenium-enriched Mushroom and Sodium Selenite on Plasma Glutathione Peroxidase Activity and Selenium Deposition in Finishing Hanwoo Steers

Effects of spent composts of selenium-enriched mushroom (Se-SMC) on plasma glutathione peroxidase (GSH-Px) activity and selenium (Se) deposition in finishing Hanwoo (Bos taurus coreanae) steers were investigated. Twenty-five Hanwoo steers (average body weight = 613 kg, average age = 22 months) were allotted to treatments in five groups of five steers per pen for 12 weeks preceding slaughter. Treatments were SMC alone (CON; 0.1 ppm Se), 0.3 ppm (0.3 Se-SMC), 0.6 ppm (0.6 Se-SMC), 0.9 ppm (0.9 Se- SMC), and 0.9 ppm (sodium selenite; SENI) Se. During the experimental period, blood samples were taken to analyze Se concentrations and GSH-Px activities. Muscle and liver samples were collected for analyses of Se contents after slaughter. Dry matter intake and body weight gain were not affected by Se-SMC or sodium selenite supplementation. Selenium concentration in the whole blood and GSH-Px activity in plasma were linearly increased (p<0.01) with increasing levels of Se-SMC. The whole blood Se concentration of SENI treatment was significantly higher (p<0.05) than that of CON treatment from 4 weeks, whereas there was no significant difference in GSH-Px activities between both treatments at 8 and 12 weeks. Selenium content in the hind leg and liver increased linearly (p<0.05) with increasing levels of Se-SMC, but those of SENI treatments were not significantly different from CON treatments. These results suggested that Se in the Se-SMC was highly bioavailable to blood and tissues of ruminants, especially compared with Se in the sodium selenite. Therefore, Se-SMC might be used not only as an inexpensive way of providing Se for ruminants but also as another way of

Opinion of the Panel on additives and products or substances used in animal feed (FEEDAP) on the safety and efficacy of the product Sel‐Plex 2000 as a feed additive according to Regulation (EC) No 1831/2003

Opinion of the Panel on additives and products or substances used in animal feed (FEEDAP) on the safety and efficacy of the product Sel‐Plex 2000 as a feed additive according to Regulation (EC) No 1831/2003

Selenium levels in related biological samples: Human placenta, maternal and umbilical cord blood, hair and nails

A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 μg/g (mean±standard deviation: 0.81±0.02 μg/g). The levels for the umbilical cord blood were 51.1–104.2 μg/l (76.3±6.5 μg/l). For the maternal blood the values measured were between 57.3 and 117.9 μg/l (90.0±15.2 μg/l), and for hair and nails were 0.22–1.5 μg/g (0.60±0.37 μg/g) and 0.46–1.57 μg/g (0.90±0.27 μg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 μg/g (1.04±0.48 μg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers’ age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns’ hair, between placenta and umbilical cord, and between cord blood and maternal blood.

Effect of reduced glutathione treatment on selenosis, blood selenium concentration and glutathione peroxidase activity after repeated short-term selenium exposure in buffalo calves

Effects of repeated feeding of selenium, when given alone or along with reduced glutathione, on whole blood selenium levels, selenosis and glutathione peroxidase activity, was studied in buffalo calves. After feeding 2.5 mg/kg of BW sodium selenite, good correlation was found between the onset of selenosis and whole blood selenium concentrations. Adverse effects appeared when the whole blood selenium concentrations increased above 2 μg/ml and mortality occurred when they exceeded 3.4 μg/ml. Reduced glutathione, given i.v. at 5 mg/kg of BW arrested the progress of selenosis and prevented mortality which was 100% in the sodium selenite supplemented group; also a reduced whole blood selenium concentration was noted. Whole blood selenium concentrations were a better and more sensitive indicator of selenium status than glutathione peroxidase activity alone.

The relationship between whole blood selenium (Se) concentration and the activity of the seleno-enzyme, glutathione peroxidase (GSH-Px, E.C.I.11.1.9) in camel ( Camelus dromedarius)

The concentration of Se and the activity of the enzyme glutathione peroxidase (GSH-Px) were investigated in the whole blood of camels. Variable concentrations of whole blood Se (0.025–0.043 μg/ml) and GSH-Px activity (6.32–18.64 EU/ml) were demonstrated in both sexes, with females having significantly higher ( P < 0.001 ) blood Se concentration and GSH-Px activity than males. A highly significant correlation ( r = 0.88 , P < 0.001 ) has been demonstrated between whole blood Se concentration and the activity of the enzyme GSH-Px.

Mercury and other Contaminants in Common Loons Breeding in Atlantic Canada

Common loons (Gavia immer) were studied to assess the biomagnification of persistent contaminants in lake ecosystems in Atlantic Canada. Forty-two breeding adults and 20 juvenile loons were captured in August, 1995-1997 on lakes in four areas of southern New Brunswick (Lepreau and Fundy National Park) and Nova Scotia (Halifax and Kejimkujik National Park). Blood samples were collected for analysis of mercury, methylmercury, lead, and selenium. Plasma samples from adult loons were analyzed for PCB congeners and organochlorine pesticides. Secondary flight feathers were collected from adult loons for mercury analysis. Kejimkujik loons had significantly higher geometric mean concentrations of mercury in blood (adults: 5.5 microg/g, wet wt) and feathers (adults: 15 microg/g, fresh wt), and higher levels of PCBs, DDE, oxychlordane, trans-nonachlor, mirex and hexachlorobenzene than loons at Halifax or Lepreau. Blood selenium levels were lowest in Kejimkujik loons. Selenium and mercury concentrations were negatively related in blood of adults across all sites. Adult males had higher concentrations of mercury in blood and feathers and PCBs, DDE, and oxychlordane in plasma, and lower levels of selenium in blood, than adult females. Juvenile loons had lower blood mercury and selenium concentrations than adults. Several contaminants showed significant inter-lake variation within the study sites. Mean blood mercury concentrations in Kejimkujik loons are the highest found in breeding common loons across North America. Of adult loons at Kejimkujik, 92% had blood mercury levels > 4 microg/g (wet wt), which have been associated with impaired reproduction, elevated corticosterone levels, asymmetry in plumage development, and altered breeding behavior in loons there and elsewhere.

Plasma Vitamin E and Blood Selenium Concentrations in Norwegian Dairy Cows: Regional Differences and Relations to Feeding and Health

Plasma α-tocopherol (vit E) and blood selenium (Se) concentrations in February were determined in samples from 314 dairy cows in Norway, selected to provide a representative subset of the Norwegian dairy cow population. Each sample was followed by a questionnaire with information about feeding of the cow at the time of sampling. The results were correlated to herd data and to calving and health data for each cow from the Norwegian Dairy Herd Recording System and the Norwegian Cattle Health Recording System. The mean concentrations were 6.9 μg vit E per ml plasma and 0.16 μg Se per g blood. Both levels were highest in mid lactation. Plasma vit E varied with the amount of silage fed to the cow, while blood Se varied with the amount of concentrates and mineral supplements, and with geographical region. No differences in vit E or Se levels were found between cows with recorded treatments for mastitis, parturient paresis or reproductive disorders in the lactation during or immediately prior to sampling, and those without such treatments. For ketosis, a small difference in blood Se was found between the groups with or without recorded treatments. It is concluded that winter-fed lactating cows in Norway had an adequate plasma level of vit E and a marginal-to-adequate level of Se.