Validation of a new point-of-care assay for determination of ß-carotene concentration in bovine whole blood and plasma.

BACKGROUND: ß-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. ß-Carotene concentrations in plasma are used to optimize ß-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure ß-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC). OBJECTIVE: The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring ß-carotene in whole blood and plasma. METHODS: ß-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene). RESULTS: Concentrations of ß-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean ± SD; n = 166): HPLC-plasma 4.23 ± 2.35 mg/L; POC-plasma 4.49 ± 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 ± 2.12 mg/L; POC-whole blood 3.67 ± 2.29 mg/L. CONCLUSIONS: Concentrations of ß-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding ß-carotene deficiency facilitates rapid and appropriate optimization of ß-carotene supplementation in feed.

Quantification of vitamin a in palm oil using a fast and simple portable device: method validation and comparison to high-performance liquid chromatography.

Vitamin A deficiency continues to be a global public health problem. Fortification of oil with vitamin A is considered a cost-effective, feasible strategy to prevent this problem but quality control poses a challenge to program implementation. To overcome this, we have validated a newly developed device that quantitatively measures the content of retinyl palmitate in refined palm oil, is simple to use, and yields immediate results.Linearity of analysis ranged from 2.5 - 30 mg retinol equivalents (RE)/ kg of palm oil, with 2.5 mg RE/kg being the determination limit; inter- and intra-assay precision ranged from 1.4 - 7.1 %. Comparison with a high-performance liquid chromatography method showed high agreement between the methods (R(2) = 0.92; Limits of Agreement: -1.24 mg to 2.53 mg RE/kg), and further comparisons illustrate that the new device is useful in low-resource settings. This device offers a field- and user-friendly solution to quantifying the vitamin A content in refined palm oil.

Concentration of carotenoids, retinol and alpha-tocopherol in plasma of six microchiroptera species.

To adequately feed species in captivity it is necessary to know their nutritional habits and their natural availability of specific nutrients. Such essential nutrients are vitamin A, vitamin E and selected carotenoids as vitamin-A-precursors. Because their blood plasma concentration are valid biomarkers of nutritional status of dietary intake, we determined the concentrations of carotenoids, retinol and alpha-tocopherol by HPLC as well as the transport proteins for retinol, the retinol-binding protein (RBP) and transthyretin (TTR) immunologically in the plasma of six species of microchiroptera from free-ranging animals and compared it in one species (Carollia perspicillata) to a group held in captivity. Plasma concentrations of the investigated components were generally much lower compared to most other mammals. Within the bats, differences were observed for all components. As in other species retinol, RBP and TTR were present but no retinyl esters could be detected. Plasma of the insectivorous bat species Molossus molossus contained carotenoids. Within the group of carotenoids, beta-carotene was dominant and only traces of lutein were present. Phyllostomus hastatus revealed the highest alpha-tocopherol concentration. No differences in the plasma content of the investigated compounds were found between a group of Carollia perspicillata kept in captivity for 20 years and free-ranging individuals from a population in Central America. No sex related differences were obvious. In conclusion, nutritional biomarkers in bats were highly variable due to dietary and possible species-specific differences.

Carotenoides y retinol plasmáticos en embarazadas a término y mujeres no embarazadas / No disponible

Fundamentos: La ingestión de carotenoides a través delas frutas y vegetales es de suma importancia en el embarazoy en el parto en su doble función como precursoresde la vitamina A y como antioxidantes.Objetivo: Evaluar la ingestión de vegetales ricos en carotenoidesy relacionarla con las concentraciones plasmáticasde cada carotenoide en un grupo de embarazadas saludablesen comparación con mujeres no embarazadas.Métodos: Se determinaron seis carotenoides y vitaminaA en el plasma de 20 embarazadas antes del parto y de20 mujeres no embarazadas. Se les aplicó una encuestade frecuencia semicuantitativa de consumo de alimentosricos en carotenoides y vitamina A de 30 días.Resultados: Las embarazadas ingirieron mayores cantidadesde vegetales que las mujeres no embarazadas. Losvegetales ricos en carotenoides de mayor consumo fuerontomate, lechuga, naranja, plátano, papaya, mandarina,plátano vianda y chícharos. Se muestra la contribuciónde los vegetales consumidos a los distintoscarotenoides. En el grupo de mujeres no embarazadas seencontró correlación entre la ingestión y los valoresplasmáticos para el afa y Beta-caroteno que desapareció enlas embarazadas; estas a pesar de haber tenido mayoresingestiones de vitamina A y licopeno disminuyeron comparativamentesus valores plasmáticos.Conclusiones: El comportamiento diferente entre embarazadasy no embarazadas parece estar dado por unamayor utilización de estos cuatro compuestos en estaúltima etapa del embarazo en su función de vitamina A ycomo antioxidantes. Las embarazadas mostraron un buenestado de la vitamina A(AU)

Background: Carotenoids intake from fruits and vegetablesis of great importance in pregnancy and birth due to itsdouble function as precursors of vitamin A and asantioxidants.Objective: To evaluate the consumption of vegetables richin carotenoids and to relate it with plasma concentrationsof each carotenoid in a group of healthy pregnant womenin comparison with non pregnant women.Methods: Six carotenoids and A vitamin were assessedin the plasma of 20 pregnant women before childbirthand in 20 non pregnant women. A semiquantitative foodfrequency questionnaire of food rich in carotenoids andvitamin A in 30 days was completed.Results: Pregnant women had higher consuption ofvegetables than non pregnant women. The most consumedvegetables rich in carotenoids were tomato, lettuce, orange,banana, papaw, nectarine, viand banana and peas.Contribution of vegetables to the intake of differentcarotenoids is shown. There was a correlation betweenvegetable consumption and plasma levels of alpha and Beta-carotene in non pregant women, but not in pregnantwomen; despite they had higher intake levels of vitamin Aand licopene, their plasma values decreased.Conclusions: There were differences in carotenoids statusbetween pregnant and non pregnant women whichseems related to a biggest use of these four compounds inthis last stage of pregnancy, both in its function of vitaminA and as antioxidants. Pregnant women show adequatenutritional status of vitamin A(AU)

[Relationship between oxidant stress and milk productivity in dairy cows]. / Der Zusammenhang zwischen Milchleistung und oxidativem Stress bei Milchkühen.

An imbalance between formation and detoxification of oxygen radicals leads to oxidant stress that may increase in more intense oxidative metabolism caused by a high intake of metabolizable energy to provide metabolic intermediates for the milk synthesis and secretion. This hypothesis was tested using dairy cows and the concentration of hydroperoxides in lipids (LHP) extracted from circulative lipoprotein particles of low and very low density (LDL and VLDL/chylomicrons) as oxidant stress indicator. The particles were prepared by ultracentrifugation of serum obtained by coccygeal bleeding (13 cows, 1. parity, n=8 and 2. parity, n=5, lactation stage, 53 +/- 1.4 days post partum) and purified by precipitation. Concentrations of LHP-LDL/mg Lipoprotein correlated significantly with daily milk yield (r = 0.73, P = 0.004) or daily milk energy output (r = 0.77, P = 0.003) in contrast to LHP of VLDL/chylomicron particles. Thus, some evidence was obtained for an almost linear, positive relationship between milk productivity and oxidant stress occurring in LDL.

Vitamin A, carotenoid and vitamin E plasma concentrations in children from Laos in relation to sex and growth failure.

BACKGROUND: Deficiencies of vitamin A and its precursors, the carotenoids are common problems in developing countries. Plasma levels of these components are used as biomarkers of their availability. The study was conducted to evaluate whether blood plasma obtained from capillaries can be compared with plasma obtained from venous blood with regard to its levels of retinol, carotenoids and alpha-tocopherol and secondly to apply this technique to evaluate the levels of these components in children in a region with possible deficiencies. METHODS: The survey was conducted in a region of Laos in 81 children (age 35 to 59 months). Dietary intake was assessed by a questionnaire. Retinol, carotenoids and alpha-tocopherol were determined by HPLC. Blood plasma was obtained either from capillary blood collected into microcapillaries and for reasons of methodological comparison in 14 adults from venous blood. RESULTS: The comparison between capillary and venous blood revealed that all components except zeaxanthin were 9-23 % higher in plasma obtained from capillary blood. Results in Laotian children showed that all investigated components except retinol were significantly lower (P < 0.01) compared to European children of slightly older age. Contrary to children in Europe, most components were significantly lower in boys compared to girls. In children from Laos, lutein was the dominant carotenoid, while in children in Europe, beta-carotene was dominant. Within the Laotian children only a few differences were observed between stunted and non-stunted children and between children from lowland areas and high land areas. CONCLUSIONS: Results show that in consideration of slightly lower levels than in venous blood, capillary blood can be used to evaluate retinol, carotenoids and alpha-tocopherol as biomarkers of intake or status and to evaluate the possible effect of diet on absolute and relative carotenoid composition in children from Europe and Laos. Observed sex related differences might not be related to diet and would need further investigation.

Carotenoides séricos y su relación con la dieta en un grupo de adultos cubanos / Serum carotenoids and their relationship with diet in a group of Cuban adults

El objetivo del trabajo fue obtener el perfil de carotenoides séricos en un grupo de adultos cubanos aparentemente sanos y relacionarlo con la ingesta dietética. En el estudio participaron 30 voluntarios (20 mujeres y 10 hombres) con edades comprendidas entre 22 y 53 años. Se les tomó una muestra de sangre para las determinaciones de carotenoides y vitamina A en el suero por cromatografía líquida de alta resolución (HPLC); paralelamente se les realizó una encuesta de frecuencia de consumo semicuantitativa que recogía la información de los alimentos consumidos los 30 días precedentes. La encuesta incluyó 38 alimentos ricos en vitamina A y carotenoides, 26 de origen vegetal y 12 de origen animal. Se hizo un estimado de los alimentos de mayor consumo y su aporte en carotenoides provitamina A y no provitamina A, así como el de vitamina A y la ingestión media de carotenoides. Los niveles medios de ingestión fueron licopeno 6,86 mg/día (dado por el consumo de tomate y papaya), betacaroteno 2,81 mg/día (principalmente tomate y zanahoria), luteína 0,79 mg/día (calabaza y chícharos), zeaxantina 0,12 Ág/día (naranjas), betacriptoxantina 1,38 mg/día (naranja y papaya) y alfacaroteno 0,60 mg/día (zanahoria y plátanos). Las medias de los carotenoides séricos fueron: licopeno 38,14 ± 15,94 Ág/dL; betacaroteno 16,64 ± 6,36 Ág/dL; luteína 16,20 ± 7,61 Ág/dL; betacriptoxantina 8,33 ± 6,03 Ág/dL; alfacaroteno 6,48 ± 3,42 mg/dL y zeaxantina 2,30 ± 0,91 Ág/dL. El perfil de carotenoides estuvo caracterizado por una elevada concentración de licopeno y alfacaroteno por un abundante consumo de tomate y plátanos respectivamente sobre los valores habituales relacionado con el consumo. Se encontró correlación entre la ingesta y los niveles séricos para los carotenoides provitamina A y la zeaxantina. Este resultado permite utilizar con buena precisión la encuesta de frecuencia de consumo en estudios epidemiológicos para la estimación de los carotenoides(AU)

Carotenoides séricos y su relación con la dieta en un grupo de adultos cubanos / Serum carotenoids and their relationship with diet in a group of Cuban adults

El objetivo del trabajo fue obtener el perfil de carotenoides séricos en un grupo de adultos cubanos aparentemente sanos y relacionarlo con la ingesta dietética. En el estudio participaron 30 voluntarios (20 mujeres y 10 hombres) con edades comprendidas entre 22 y 53 años. Se les tomó una muestra de sangre para las determinaciones de carotenoides y vitamina A en el suero por cromatografía líquida de alta resolución (HPLC); paralelamente se les realizó una encuesta de frecuencia de consumo semicuantitativa que recogía la información de los alimentos consumidos los 30 días precedentes. La encuesta incluyó 38 alimentos ricos en vitamina A y carotenoides, 26 de origen vegetal y 12 de origen animal. Se hizo un estimado de los alimentos de mayor consumo y su aporte en carotenoides provitamina A y no provitamina A, así como el de vitamina A y la ingestión media de carotenoides. Los niveles medios de ingestión fueron licopeno 6,86 mg/día (dado por el consumo de tomate y papaya), betacaroteno 2,81 mg/día (principalmente tomate y zanahoria), luteína 0,79 mg/día (calabaza y chícharos), zeaxantina 0,12 µg/día (naranjas), betacriptoxantina 1,38 mg/día (naranja y papaya) y alfacaroteno 0,60 mg/día (zanahoria y plátanos). Las medias de los carotenoides séricos fueron: licopeno 38,14 ± 15,94 µg/dL; betacaroteno 16,64 ± 6,36 µg/dL; luteína 16,20 ± 7,61 µg/dL; betacriptoxantina 8,33 ± 6,03 µg/dL; alfacaroteno 6,48 ± 3,42 mg/dL y zeaxantina 2,30 ± 0,91 µg/dL. El perfil de carotenoides estuvo caracterizado por una elevada concentración de licopeno y alfacaroteno por un abundante consumo de tomate y plátanos respectivamente sobre los valores habituales relacionado con el consumo. Se encontró correlación entre la ingesta y los niveles séricos para los carotenoides provitamina A y la zeaxantina. Este resultado permite utilizar con buena precisión la encuesta de frecuencia de consumo en estudios epidemiológicos para la estimación de los carotenoides