Vitamin D and provitamin D in fish

A highly-sensitive high-performance liquid chromatographic method for measuring vitamin D₃ and provitamin D₃ in the edible part of fish was developed. The sample preparation procedure consisted of cold saponification and liquid/liquid extraction of the unsaponifiable matter using a disposable kieselguhr cartridge. For the purification of the sample extracts a semipreparative stage using normal-phase HPLC with UV-detection was applied. A vitamin D and a provitamin D fraction was collected and subsequently quantified by analytical reversed-phase HPLC with electrochemical detection. Internal standardization was used for quantitation. The accuracy of this method was evaluated by recovery experiments. The investigated fish included most of the important fish species consumed in Germany.     

Vitamin D Stability in Milk

A method was developed to determine vitamin D₃ in milk. It includes saponification, solid phase extraction and HPLC. Recovery of added vitamin D₃ was 93%. Vitamin D₃ concentrations in commercial milks were variable. Stability studies showed that on exposure to light, there was a slight loss of vitamin D₃ from fortified milk. Air exposure did not affect stability in milk. Upon standing there was some stratification of the vitamin in milk containers with slightly more vitamin D₃ in the top layer of milk than at the bottom.     

Several parameters of the nutritional status of indigenous population of Far North

Presented are the results of nutrition status of 803 inhabitants of Yakutia both sexes at the age from 20 to 50. 22 per cent of examined men and 42 per cent of examined women had redundant body mass. It relates to high caloric diet and unbalance between consumption and expense of energy. High caloric diet is a cause of hypercholesterinemia and hypertriglyceridemia among young and old people. The most part of residents had insufficiency of vitamin C and beta-carotene in winter. It relates to deficit of fruit and vegetables in diet. 8 per cent of examined men and 30 per cent of examined women had low level of hemoglobin. Thus, rational nutrition is necessary for prophylaxis diseases in the Far North.     

Fusarium avenaceum -- the North European situation

The Fusarium species complex found on small-grain cereals in Northern Europe is largely dominated by F. avenaceum, while other important species include F. tricinctum, F. poae, F. culmorum and F. graminearum. The dominance of F. avenaceum has in recent years initiated extensive analytical activity in Norway and Finland in order to gain insight into the contamination of grain with secondary metabolites related to the fungus. Of these, moniliformin is the most studied compound with regard to toxicity. However, the data from analytical surveys indicate that field conditions in Northern Europe do not favour production of the metabolite. Instead, enniatins are regularly found in ppm-concentrations in grain, especially wheat and barley, while the bio-production of a range of other F. avenaceum related metabolites has so far barely been investigated. This paper summarises the results from mycological and chemical analyses of grain samples from Norway and Finland for major Fusarium species and F. avenaceum-related secondary metabolites.     

Vitamin D Bioavailability: State of the Art

There has been renewed interest in vitamin D since numerous recent studies have suggested that besides its well-established roles in bone metabolism and immunity, vitamin D status is inversely associated with the incidence of several diseases, e.g., cancers, cardio-vascular diseases, and neurodegenerative diseases. Surprisingly, there is very little data on factors that affect absorption of this fat-soluble vitamin, although it is acknowledged that dietary vitamin D could help to fight against the subdeficient vitamin D status that is common in several populations. This review describes the state of the art concerning the fate of vitamin D in the human upper gastrointestinal tract and on the factors assumed to affect its absorption efficiency. The main conclusions are: (i) ergocalciferol (vitamin D₂), the form mostly used in supplements and fortified foods, is apparently absorbed with similar efficiency to cholecalciferol (vitamin D₃, the main dietary form), (ii) 25-hydroxyvitamin D (25OHD), the metabolite produced in the liver, and which can be found in foods, is better absorbed than the nonhydroxy vitamin D forms cholecalciferol and ergocalciferol, (iii) the amount of fat with which vitamin D is ingested does not seem to significantly modify the bioavailability of vitamin D₃, (iv) the food matrix has apparently little effect on vitamin D bioavailability, (v) sucrose polyesters (Olestra) and tetrahydrolipstatin (orlistat) probably diminish vitamin D absorption, and (vi) there is apparently no effect of aging on vitamin D absorption efficiency.

We also find that there is insufficient, or even no data on the following factors suspected of affecting vitamin D bioavailability: (i) effect of type and amount of dietary fiber, (ii) effect of vitamin D status, and (iii) effect of genetic variation in proteins involved in its intestinal absorption.

In conclusion, further studies are needed to improve our knowledge of factors affecting vitamin D absorption efficiency. Clinical studies with labeled vitamin D, e.g., deuterated or ¹³C, are needed to accurately and definitively assess the effect of various factors on its bioavailability.     

Vitamin D3 toxicity in dairy cows

Large parenteral doses of vitamin D3 (15 to 17.5 x 10(6) IU vitamin D3) were associated with prolonged hypercalcemia, hyperphosphatemia, and large increases of vitamin D3 and its metabolites in the blood plasma of nonlactating nonpregnant and pregnant Jersey cows. Calcium concentrations 1 day postpartum were higher in cows treated with vitamin D3 about 32 days prepartum (8.8 mg/100 ml) than in control cows (5.5 mg/100 ml). None of the cows treated with vitamin D3 showed signs of milk fever during the peripartal period; however, 22% of the control cows developed clinical signs of milk fever during this period. Signs of vitamin D3 toxicity were not observed in nonlactating nonpregnant cows; however, pregnant cows commonly developed severe signs of vitamin D3 toxicity and 10 of 17 cows died. There was widespread metastatic calcification in the cows that died. Because of the extreme toxicity of vitamin D3 in pregnant Jersey cows and the low margin of safety between doses of vitamin D3 that prevent milk fever and doses that induce milk fever, we concluded that vitamin D3 cannot be used practically to prevent milk fever when injected several weeks prepartum.     

Vitamin D binding factors in bovine blood.

Both 25 [25,26-hydrogen-3] hydroxycholecalciferol and [1alpha,2alpha-hydrogen-3] cholecalciferol were added to bovine plasma in vitro. Analysis by gel-filtration and ion exchange chromatography, electrophoresis, ultracentrifugation, competitive binding specificity studies, and plasma stripping showed that vitamin D circulated with a protein of alpha-globulin mobility. This globulin had a much higher affinity for 25-hydroxycholecalciferol while vitamin D3 appeared to be associated first with an alpha-lipoprotein and with time because associated with the alpha-globulin. This alpha-globulin had a molecular weight of approximately 70,000 as determined by gel-filtration. Cholecalciferol appeared to bind tightly to the alpha-lipoprotein and resisted being stripped from the plasma. Thus, alpha-globulin appears to be the major carrier of vitamin D in the blood while the alpha-lipoprotein may aid in the transfer of cholecalciferol from the gut to the liver via the lymph system.     

Vitamin D status and glucose metabolism in youth

This study aimed to review and synthesize the available scientific evidence on the relationship between serum 25(OH)D concentrations and glucose metabolism among adolescents. A total of 19 studies were included. Many studies did not find a relation between 25(OH)D concentrations and insulin sensitivity, but most studies have shown that vitamin D status influences glucose dysregulation in youth due to particularities of this life stage. Considering the prevalence of vitamin D deficiency and insufficiency were high among adolescents, the importance for vitamin D status correction in this young group, in which chronic diseases are not expected but getting every day more common, is mandatory.     

Lipids metabolism at aboriginal adolescents in Russian European North

The aim of our research was to investigate the contents of lipids and fat-soluble vitamins in blood plasma of aboriginal adolescents of Russian European North (komi, n=104). It was established that there are specific Lipemic index at aboriginal adolescents: low level of the general cholesterol, triglycerides, transport lipoproteins both their albuminous components and raised proportion omega-6/omega-3 fatty acids concerning recommended specifications. Level of fat-soluble vitamins also has been considerably lowered. Adolescents living in 62 degrees N differed as a completely higher level of atherogenous fractions of lipids, than the adolescents of Circumpolar regions (65 degrees N) having traditional     

Dynamics of indigenous yeast populations during spontaneous fermentation of wines from Mendoza, Argentina

Fermentation of wine is a complex microbial reaction, which involves the sequential development of various species of yeasts and lactic acid bacteria. Of these, yeasts are the main group responsible for alcoholic fermentation. The aim of this work was to study, under industrial conditions, the evolution of yeast populations and to describe the individual evolution of the most important yeasts during three spontaneous fermentations of Malbec musts from Argentina. This work shows the significant participation of non-Saccharomyces yeasts during spontaneous fermentation of musts, with the ubiquitous presence of three main species: Kloeckera apiculata, Candida stellata and Metschnikowia pulcherrima.     

Prevalence of overweight and obesity among indigenous populations in Canada: A systematic review and meta-analysis

Previous studies on overweight and obesity among indigenous peoples in Canada have been inconclusive. A systematic review was conducted on the prevalence of overweight and obesity among Canadian indigenous populations. Major bibliographic databases were searched for relevant studies published between January 1990 and June 2013. We reviewed 594 abstracts and included 41 studies in the meta-analyses. Using the heterogeneity test (Cochrane Q) results, the overall prevalence was estimated using fixed- or random-effects model. Nonadults (<18 years) had a pooled prevalence of overweight and obesity at 29.8% (95% CI: 25.2–34.4) and 26.5% (95% CI: 21.8–31.3), respectively. The pooled prevalence of overweight and obesity among adults were 29.7% (95% CI: 28.2–31.2) and 36.6% (95% CI: 32.9–40.2), respectively. Adult males had higher overweight prevalence than females (34.6% vs. 26.6%), but lower obesity prevalence (31.6% vs. 40.6%). Nonadult girls had higher prevalence than boys [overweight: 27.6%; 95% CI: 22.6–32.7 vs. 24.7%; 95% CI: 19.0–30.5; obesity: 28.6%; 95% CI: 20.3–36.9 vs. 25.1%; 95% CI: 13.8–36.4]. Nonadult Inuit had the highest overweight and lowest obesity prevalence. Although Inuit adult had the lowest prevalence of overweight (28.7%; 95% CI: 27.3–30.2) and obesity (32.3%; 95% CI: 25.5–39.1), it was relatively high. This study highlights the need for nutritional intervention programs for obesity prevention among indigenous populations in Canada.     

维生素D改善肥胖大鼠的脂代谢

本文研究维生素D改善肥胖大鼠脂代谢的作用。建立肥胖大鼠模型,正常组、模型组、高剂量组(2.40μg/mL)、中剂量组(1.20μg/mL)、低剂量组(0.60μg/mL)、奥利司他组(0.10 mg/mL)。统计体重、体长、Lee’s指数、附睾脂肪垫质量、脂肪体重指数,检测总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C),观察大鼠脂肪细胞形态学,检测过氧化物酶体增殖物激活受体γ(PPAR-γ)、瘦素、线粒体解偶联蛋白(UCP)蛋白表达。高剂量组大鼠体重250.76 g、Lee’s指数2.52%、附睾脂肪垫质量5.05 g、脂肪体重指数1.41 g、TC 1.96 mmol/L、TG 0.83 mmol/L、LDL-C 1.05 mmol/L低于模型组大鼠,HDL-C 0.59mmol/L高于模型组大鼠(p0.05)。高剂量组大鼠PPAR-γ、瘦素蛋白表达低于模型组大鼠,高剂量组大鼠UCP蛋白表达高于模型组大鼠(p0.05)。维生素D通过调控PPAR-γ、瘦素、UCP蛋白表达,改善大鼠脂代谢。     

Riboflavin Photosensitized Singlet Oxygen Oxidation of Vitamin D

Samples containing various levels of vitamin D and riboflavin, with and without ascorbic acid or a-tocopherol were prepared in a model system. Samples were stored in the light or in the dark at 45®C for up to 8 h. Headspace oxygen was determined by gas chromatography with thermal conductivity detection. Oxidation of vitamin D was not observed in samples without riboflavin stored in the light nor in samples with riboflavin stored in the dark. Vitamin D with riboflavin was oxidized under light. α-Tocopherol quenched singlet oxygen at a rate of 2.52 × 10⁸ M^-1 sec^-1, whereas ascorbic acid quenched singlet oxygen at a rate of 2.23 × 10⁷ M^-1 sec^-1.     

Comparison of enterococcal populations in animals, humans, and the environment--a European study

The objectives of the present study were to generate knowledge of enterococcal populations in the food chain, by studying the population structure (in measures of abundance and diversity) among enterococci in different geographical regions and in different parts of the food chain, as well as the similarities between different enterococcal populations. Altogether, 2868 samples were collected from humans (healthy and hospitalised individuals and clinical isolates), animals (slaughterhouse carcasses and farm animals), and the environment (pig farms, sewage, and surface water) in four European countries-Sweden, Denmark, UK, and Spain. The samples were characterised with regard to presence and numbers of enterococci, and eight (for faecal samples) or 24 (for environmental samples) isolates per sample were phenotyped and preliminarily identified with the PhP-RF system. In total, more than 20,000 isolates were typed. A majority of the samples (77%) showed the presence of presumed enterococci. The diversities of enterococci in environmental samples were generally high, and also faecal samples normally showed presence of more than one enterococcal strain. The most common species found were Enterococcus faecium (33%), E. faecalis (29%), and E. hirae (24%), but different enterococcal populations differed in their species distribution. Clinical isolates, hospitalised patients, and hospital sewage in Sweden showed a clear dominance of E. faecalis (80%, 57%, and 54%, respectively) whereas healthy individuals and urban sewage contained less E. faecalis (39% and 40%, respectively). The species distribution among isolates from slaughterhouses varied between animal species and also between countries, but E. faecalis seemed to be mainly associated with broiler, and E. hirae with cattle and pigs. The results from the study have indicated a simplified method to study the diversity of bacterial populations. Instead of collecting many samples and analysing one or a few isolates per sample, it is possible to collect fewer samples and analyse several isolates per sample. Both approaches yielded similar information on the diversity of the populations. Another useful information was that since samples from hospital sewage, urban sewage, and manure contained enterococcal populations that reflected those in faecal samples of hospitalised patients, healthy humans, and animals, respectively, such samples may be used as pooled faecal samples and may replace cumbersome samplings from many individuals.     

Effects of Vitamin D3‐Enriched Diet on Egg Yolk Vitamin D3 Content and Yolk Quality

A 40‐wk experiment was conducted using Hy‐Line W‐36 laying hens (19‐wk old) to investigate the impact of feeding cholecalciferol‐enriched diets on egg yolk quality. Feeds were enriched with 4 cholecalciferol levels, 9700 (diet 2), 17200 (diet 3), 24700 (diet 4), and 102200 (diet 5) IU/kg feed. The control (diet 1) contained 2200 IU cholecalciferol/kg feed. Eggs from each replicate group of enriched diets were collected daily and the yolks were pooled into 2‐d period during the first 2 wk. During weeks 3, 4, 6, 8, 12, 16, 20, 24, 28, 32, 36, and 40, pooled samples were generated by daily collection of 3 consecutive days of egg production. The cholecalciferol content of egg yolk from the enriched diets increased rapidly during the first 3 wk. The peak cholecalciferol concentrations in egg yolk that occurred at week 3 were 865, 1641, 2411, and 34815 IU/100 g egg yolk (wet basis) from diet 2 to 5. The average cholecalciferol concentration in yolk during weeks 3 to 40 and the deposition rate of cholecalciferol during the first 3 wk were both linearly increased with the dietary cholecalciferol level when the feed contained no more than 24700 IU/kg cholecalciferol. Egg yolk lipid profile (total lipid content, fatty acid composition, phospholipid composition, and unsaponifiables), physical and functional properties (yolk viscosity and emulsifying property), and sensory quality of hard‐boiled egg yolk were not affected by the cholecalciferol enrichment in the feed. Practical Application: A linear dose‐response relationship between dietary vitamin D₃ level and egg yolk vitamin D₃ content was established at relatively low enrichment levels. Such relationship can be used to formulate feed to achieve a target egg vitamin D level. High vitamin D yolk showed no difference from the conventional yolk in other compositional, functional, and sensory properties.