Combination of a solid phase extraction and a two-dimensional LC-UV method for the analysis of vitamin D3 and its isomers in olive oil.

The current HPLC methods for the quantification of vitamin D3 (VitD3) and its two isomers previtamin D3 (PreVitD3) and trans-vitamin D3 (trans-VitD3) in olive oil preparations present some limitations mainly due to peak overlapping of the oily matrix components with the compounds of interest. The use of two-dimensional liquid chromatography (2D-LC) with different retention mechanism can reach higher resolving power thus allowing the analysis of complex samples. The present paper proposes a new alternative method including a solid phase extraction sample preparation step and a two-dimensional liquid chromatographic analysis using routine instrumentation, fitting the needs of quality assurance and quality control laboratories of pharmaceutical companies. The extraction protocol was demonstrated to provide a clean-up of the sample and a quantitative recovery of the species of interest. The 2D method proved its suitability in the isolation of vitamins from oil components in the first dimension and the separation and quantification of the analytes in the second dimension thanks to the orthogonal selectivities of phenyl and porous graphitic carbon (PGC) stationary phases. The method was validated following ICH guidelines and possesses an adequate sensitivity to quantify the impurity trans-VitD3 in pharmaceuticals considering the limits imposed by regulatory agencies. The applicability of the phenyl x PGC 2D-LC-UV method to quality control of medicinal products based on VitD3 in olive oil was confirmed by the successful quantification of vitamins in olive oil formulations.

A robust method for simultaneous determination of eight B vitamins in human serum by liquid chromatography tandem mass spectrometry.

The level of vitamin B group in human serum is an important index of human health. Among B vitamins, cyanocobalamin in serum is unstable and its content is extremely low. Rapid and simultaneous detection of multiple B vitamins including cyanocobalamin is a challenge. Herein, we have developed a rapid and stable method that can realize the determination of thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxic acid, biotin, 5-methyltetrahydrofolate, and cyanocobalamin simultaneously in 6 min. The method was established based on protein precipitation with methanol and then chromatographic separation was achieved using Waters acquity ultra-high-performance liquid chromatography high strength silica T3 column, which was stable and sensitive especially for cyanocobalamin. Limit of quantification, precision, trueness, and matrix effect were validated according to the European Medicines Agency and United States Food and Drug guidelines and Clinical and Laboratory Standards Institute guidelines on bioanalytical method. The limit of quantification for thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxic acid, biotin, 5-methyltetrahydrofolate, and cyanocobalamin was 0.4, 0.4, 0.8, 2.0, 0.4, 0.1, 0.4, and 0.04 ng/mL separately, respectively. Intra- and interday precisions were 1.1%-12.4% and 2.0%-13.5%, respectively. The relative errors were between 0.3% and 13.3%, and the matrix effects were between 2.6% and 10.4%.

Association of Air Pollution with a Urinary Biomarker of Biological Aging and Effect Modification by Vitamin K in the FLEMENGHO Prospective Population Study.

BACKGROUND: A recently developed urinary peptidomics biological aging clock can be used to study accelerated human aging. From 1990 to 2019, exposure to airborne particulate matter (PM) became the leading environmental risk factor worldwide. OBJECTIVES: This study investigated whether air pollution exposure is associated with accelerated urinary peptidomic aging, independent of calendar age, and whether this association is modified by other risk factors. METHODS: In a Flemish population, the urinary peptidomic profile (UPP) age (UPP-age) was derived from the urinary peptidomic profile measured by capillary electrophoresis coupled with mass spectrometry. UPP-age-R was calculated as the residual of the regression of UPP-age on chronological age, which reflects accelerated aging predicted by UPP-age, independent of chronological age. A high-resolution spatial-temporal interpolation method was used to assess each individual's exposure to PM10, PM2.5, black carbon (BC), and nitrogen dioxide (NO2). Associations of UPP-age-R with these pollutants were investigated by mixed models, accounting for clustering by residential address and confounders. Effect modifiers of the associations between UPP-age-R and air pollutants that included 18 factors reflecting vascular function, renal function, insulin resistance, lipid metabolism, or inflammation were evaluated. Direct and indirect (via UPP-age-R) effects of air pollution on mortality were evaluated by multivariable-adjusted Cox models. RESULTS: Among 660 participants (50.2% women; mean age: 50.7 y), higher exposure to PM10, PM2.5, BC, and NO2 was associated with a higher UPP-age-R. Studying effect modifiers showed that higher plasma levels of desphospho-uncarboxylated matrix Gla protein (dpucMGP), signifying poorer vitamin K status, steepened the slopes of UPP-age-R on the air pollutants. In further analyses among participants with dpucMGP ≥4.26µg/L (median), an interquartile range (IQR) higher level in PM10, PM2.5, BC, and NO2 was associated with a higher UPP-age-R of 2.03 [95% confidence interval (CI): 0.60, 3.46], 2.22 (95% CI: 0.71, 3.74), 2.00 (95% CI: 0.56, 3.43), and 2.09 (95% CI: 0.77, 3.41) y, respectively. UPP-age-R was an indirect mediator of the associations of mortality with the air pollutants [multivariable-adjusted hazard ratios from 1.094 (95% CI: 1.000, 1.196) to 1.110 (95% CI: 1.007, 1.224)] in participants with a high dpucMGP, whereas no direct associations were observed. DISCUSSION: Ambient air pollution was associated with accelerated urinary peptidomics aging, and high vitamin K status showed a potential protective effect in this population. Current guidelines are insufficient to decrease the adverse health effects of airborne pollutants, including healthy aging trajectories. https://doi.org/10.1289/EHP13414.

Rapid simultaneous determination of 7 fat-soluble vitamins in human serum by ultra high performance liquid chromatography tandem mass spectrometry.

Accurate detection of vitamins is critically important for clinical diagnosis, metabolomics and epidemiological studies. However, the amounts of different vitamins vary dramatically in human serum. It is a challenge to achieve simultaneous detection of multiple vitamins rapidly. Herein, we developed and validated a sensitive and specific method using ultra high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for simultaneous quantification of 7 fat-soluble vitamins (FSVs) across their physiological concentrations in serum for the first time, which was subjected to protein precipitation, liquid-liquid extraction to an organic phase, evaporation to dryness and reconstitution with acetonitrile. In the present procedure, retinol (vitamin A), ergocalciferol (25-OH-D2), cholecalciferol (25-OH-D3), α-tocopherol (vitamin E), phylloquinone (vitamin K1), menatetrenone-4 (MK-4), and menaquinone-7 (MK-7) were detected in one analytical procedure for the first time within 5.0 min by triple quadrupole tandem mass spectrometry. The limit of quantification (LOQ) for vitamin A was 10.0 ng mL-1, LOQs for 25-OH-D2 and 25-OH-D3 were 1.0 ng mL-1, LOQ for vitamin E was 100.0 ng mL-1, and LOQs for vitamin K1, MK-4 and MK-7 were 0.10 ng mL-1, respectively, with a correlation (R2) of 0.995-0.999. Recoveries ranged from 80.5% to 118.5% and the intra-day and inter-day coefficients of variance (CVs) were 0.72-8.89% and 3.2-9.0% respectively. The method was validated according to the European Medicines Agency (EMA) and U.S. Food and Drug guidelines and C62-A on bioanalytical methods, and was used for clinical routine determination.

The association between umbilical cord blood fat-soluble vitamin concentrations and infant birth weight.

Background: Fat-soluble vitamins, including vitamins A, D and E, play an important role in the regulation of glucose and lipid metabolism, and may affect infant birth weight. Evidence on the association of birthweight with fat-soluble vitamins is controversial. Therefore, this study aims is to determine the associations of birthweight with vitamin A, D, and E concentrations in cord blood. Methods: A total of 199 mother-infant pairs were enrolled in the study. According to gestational age and birth weight, the mother-infant pairs were divided into small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). The Vitamin A, D, and E concentrations in serum were measured by high-performance liquid chromatography tandem-mass spectrometry. Results: The concentrations of vitamin A in the SGA group were significantly lower than those in the AGA and LGA groups. The concentrations of vitamin E in the SGA group were significantly higher than those in the AGA and LGA groups. However, no significant differences were observed in vitamin D among the three groups. Being male (ß = 0.317, p < 0.001) and birth weight (ß = 0.229, p = 0.014) were positively correlated with the levels of vitamin A. Birth weight (ß = -0.213, p= 0.026) was correlated with lower levels of vitamin E. No correlation was found between influencing Factors and the levels of vitamin D (p> 0.05). After adjusting for gestational age, sex, mother's age, delivery mode, pre-pregnancy BMI, and weight gain during pregnancy, the levels of cord blood vitamin A were positively correlated with birth weight (p=0.012). Conclusion: The infant's birth weight is associated with the levels of cord blood vitamins A and E. The dysregulation of vitamins A and E in infants may be a risk factor for fetal growth and future metabolic diseases.

Quantification of 10 B vitamins in mouse colon by LC-MS/MS: Application on breast cancer mice treated with doxorubicin.

B vitamins play important roles in various physiological processes, including cell metabolism and DNA synthesis. The intestine is critical for the absorption and utilization of B vitamins, but few analytical methods for detecting intestinal B vitamins are currently available. In this study, we developed a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of 10 B vitamins in mouse colon tissue, including thiamin (B1), riboflavin (B2), nicotinic acid (B3), niacinamide (B3-AM), pantothenic acid (B5), pyridoxine (B6), pyridoxal 5'-phosphate (B6-5P), biotin (B7), folic acid (B9), and cyanocobalamin (B12). The method was thoroughly validated following the U.S. Food and Drug Administration (FDA) guidelines and yielded good results in terms of linearity (r2 > 0.9928), lower limit of quantification (40-600 ng/g), accuracy (88.9-119.80 %) and precision (relative standard deviation ≤ 19.71 %), recovery (87.95-113.79 %), matrix effect (91.26-113.78 %), and stability (85.65-114.05 %). Furthermore, we applied our method to profile B vitamins in the colons of mice with breast cancer after doxorubicin chemotherapy treatment, which revealed that the doxorubicin treatment led to significant colon damage and accumulation of several B vitamins including B1, B2 and B5. We also confirmed the capability of this method for quantifying B vitamins in other intestinal tissues like the ileum, jejunum, and duodenum. The newly developed method is simple, specific, and useful for targeted profiling of B vitamins in mouse colon, with a potential for future studies on the role of these micronutrients in healthy and diseased states.

A Miniaturized Sample Preparation Method for the Determination of Vitamins A and E in Food Products.

A new analytical approach to the simultaneous identification and quantification of vitamins A and E in three representative matrices (Parmesan, spinach, and almonds) was developed. The analyses were based on high-performance liquid chromatography with UV-VIS/DAD detection. The procedure was optimized by a significant reduction in the weight of the tested products and quantities of reagents added during the saponification and extraction stages. A full method validation study was performed for retinol at two concentration levels (LOQ and 200 × LOQ), which showed satisfactory results, with recoveries ranging from 98.8 to 110.1%, and an average CV of 8.9%. Linearity was tested in the range of 1-500 µg/mL and showed the coefficient of determination R2 = 0.999. The satisfactory recovery and precision parameters were achieved for α-tocopherol (LOQ and 500 × LOQ) in the range of 70.6-143.2%, with a mean CV equal to 6.5%. The observed linearity for this analyte in the concentration range of 1.06-532.0 µg/mL was R2 = 0.999. The average extended uncertainties were estimated, using a top-down approach of 15.9% and 17.6% for vitamin E and A, respectively. Finally, the method was successfully applied to determine vitamins in 15 commercial samples.

Recovery of Polyphenolic Compounds and Vitamins from the Stinging Nettle Leaves: Thermal and Behavior and Biological Activity of Obtained Extracts.

Stinging nettle (SN) is an extraordinary plant from the Urticaceae botanical family. It is well-known and widely used in food and folk medicine to treat different disorders and diseases. This article aimed to study the chemical composition of SN leaves extracts, i.e., polyphenolic compounds and vitamins B and C, because many studies ascribed high biological potency to these compounds and their significance in the human diet. Besides the chemical profile, the thermal properties of the extracts were studied. The results confirmed presence of many polyphenolic compounds and vitamins B and C. It also showed that the chemical profile closely correlated with the applied extraction technique. The thermal analysis showed that analyzed samples were thermally stable up to about 160 °C. Thermal degradation of samples UAE, MAE, and MAC took place in four steps, and sample SE in three steps. Altogether, results confirmed the presence of health-beneficial compounds in stinging nettle leaves and indicated the possible application of its extract in pharmaceutical and food industries as both a medicinal and food additive.

Exploring the unexplored: A characterization of vitamins and vitamers in white grape musts by high-performance liquid chromatography.

Although prime compounds in yeast metabolism, vitamins in oenology have remained mostly unexplored for decades. Here, a premier characterization of the vitamers in white grape musts has been drawn. A RP-HPLC method has therefore been developed for their direct analysis in musts, allowing for the determination of 19 different vitamers from 8 water-soluble vitaminic groups, including thiamine forms T, TMP and TPP, with LODs between 0.1 and 45.9 µg.L-1 and LOQs between 0.4 and 137.8 µg.L-1. A resulting characterization of 85 grape musts has been drawn from their vitaminic composition. Plus, the use of neither sulfites nor filtration affects the must vitamin content. The method stands as a useful tool for the later determination of yeast requirements, or impact of winemaking products on vitamins. The method has, overall, proven as practical and sensitive, for rapid identification of vitamins and vitamers in musts.

Vitamin K content of cheese, yoghurt and meat products in Australia.

Vitamin K is vital for normal blood coagulation, and may influence bone, neurological and vascular health. Data on the vitamin K content of Australian foods are limited, preventing estimation of vitamin K intakes in the Australian population. We measured phylloquinone (PK) and menaquinone (MK) -4 to -10 in cheese, yoghurt and meat products (48 composite samples from 288 primary samples) by liquid chromatography with electrospray ionisation-tandem mass spectrometry. At least one K vitamer was found in every sample. The greatest mean (± standard deviation for foods sampled in multiple cities) concentrations of PK (4.9 µg/100 g), MK-4 (58 ± 9 µg/100 g) and MK-9 (8 ± 2 µg/100 g) were found in lamb liver, chicken leg meat and Cheddar cheese, respectively. Cheddar cheese (1.1 ± 0.3 µg/100 g) and cream cheese (1.0 µg/100 g) contained MK-5. MK-8 was found in Cheddar cheese only (4 ± 2 µg/100 g). As the K vitamer profile and concentrations appear to vary considerably by geographical location, Australia needs a vitamin K food composition dataset that is representative of foods consumed in Australia.

The evaluation of vitamin K status in children with febrile seizure.

BACKGROUND: Febrile seizure is the most common neurological disorder in childhood. The exact pathophysiology of febrile seizures is unknown. Recent studies showed the role of vitamin K in nonhematological and inflammatory disorders. This study aimed to investigate the serum vitamin K levels in children with febrile seizures. AIMS: To evaluate vitamin K levels in children with febrile seizures. STUDY DESIGN: Prospective case-control study. METHODS: This multicenter study examined representative populations in 8 different cities in Turkey between April 1, 2018 and April 1, 2019. Blood samples were taken from all children at presentation. Vitamin K1, vitamin K2, tumor necrosis factor-alpha, interleukin 1 beta, and interleukin 6 levels were determined by enzyme-linked immunosorbent assay. RESULTS: A total of 155 children were included in the study-84 children with febrile seizures and 71 children in febrile control group. Serum vitamin K1 and vitamin K2 levels were also higher in children with febrile seizures than in the controls. The results of statistical analysis showed that vitamin K1 and vitamin K2 levels were correlated with tumor necrosis factor-alpha, interleukin 1 beta, and interleukin 6 levels. The median vitamin K1 and vitamin K2 levels of children experiencing their first febrile seizure were higher than those in children with recurrent febrile seizures. Type of febrile seizure has no effect on serum vitamin K1 and vitamin K2 levels. CONCLUSION: In children with febrile seizures, vitamin K levels are higher than those in the control group. These new findings may contribute to elucidating the etiopathogenesis of febrile seizures.

Vitamin K intake and breast cancer incidence and death: results from a prospective cohort study.

BACKGROUND & AIMS: Vitamin K prevents growth and metastasis of certain cancers, but there is little evidence regarding the association between dietary vitamin K and breast cancer incidence and death. We sought to examine whether intakes of total vitamin K, phylloquinone (vitamin K1) and menaquinones (MKs) (vitamin K2) may influence risks of breast cancer incidence and death in the US population. METHODS: Herein, 2286 breast cancer cases and 207 breast cancer deaths were identified during 702,748 person-years of follow-up. Cox regression and competing risk regression were used to estimate multivariable-adjusted hazards ratios (HRs) and 95% confidence intervals (95% CIs) by dietary vitamin K intake quintile (Q) for risk of breast cancer incidence and mortality. RESULTS: After adjustment for confounders, the total MK intake was associated with an increased risk of breast cancer (HR Q5 vs Q1, 1.26; 95% CI, 1.05 to 1.52; Ptrend, 0.01) and death from breast cancer (HR Q5 vs Q1, 1.71; 95% CI, 0.97 to 3.01; Ptrend, 0.04). Non-linear positive dose-response associations with risks of breast cancer incidence and death were found for total MKs intake (Pnon-linearity<0.05). No statistically significant associations were observed between the intake of total vitamin K and phylloquinone and breast cancer. CONCLUSIONS: The present study suggests that total MK intake was associated with an altered risk of the occurrence and death of breast cancer in the general US population. If our findings are replicated in other epidemiological studies, reducing dietary intake of menaquinones may offer a novel strategy for breast cancer prevention.

Vitamin K (phylloquinone and menaquinones) in foods - Optimisation of extraction, clean-up and LC-ESI-MS/MS method for quantification.

Growing evidence of vitamin K's importance in human health beyond blood coagulation and bone health necessitates its further research. A method involving extraction, lipase treatment, clean-up, and detection and quantification by LC-ESI-MS/MS of phylloquinone (PK), menaquinone-4 (MK-4), menaquinone-7 (MK-7) and menaquinone-9 (MK-9) was developed, and single-laboratory validated. The matrices included in the validation were hazelnut, cheese, broccoli, and pork. The LC-method runtime was 9 min. The LOQ for PK, MK-4 and MK-7 was 0.5 µg/100 g food, while for MK-9 it was 2.5 µg/100 g food. The intra- and inter-day precision was <15% for endogenous and spiked levels, except for low content at 4 times the LOQ. Trueness was assessed to be in the range 94-125% for spiking at levels approximately 4 and 10 times LOQ. It is further shown that deuterium labelled MK-7 can be used as an internal standard for MK-9.

Vitamin K Intake in Chronic Stroke: Implications for Dietary Recommendations.

Previous research has identified a possible association between vitamin K intake and cardiometabolic disease. This could mean that the assessment of vitamin K intake is a meaningful tool when monitoring individuals with preexisting cardiovascular disease. Sixty chronic stroke survivors (men and women, body mass index (BMI) 30.36 ± 6.61 kg/m2, age 61.7 ± 7.2 years) completed food records which were analyzed for energy, macronutrient, micronutrient, and food group servings. Participants were divided into two groups: below vitamin K recommendation (BEL, n = 49) and met vitamin K recommendation (MET, n = 11). Energy and macronutrient intake did not differ between groups (all p > 0.127). Vegetable intake was higher in the MET group (p = 0.0001). Vitamin K intake was higher in the MET group (p = 0.0001). Calcium (p = 0.003), vitamin A (p = 0.007), and vitamin E (p = 0.005) intakes were higher in the MET group. There were no differences in sodium, potassium, vitamin D, vitamin C, and iron intakes between groups (all p > 0.212). In this sample of chronic stroke survivors, 82% reported consuming below the Dietary Reference Intake (DRI) for vitamin K. Given that the majority of this study population did not reach the DRI for vitamin K, it is advisable to promote the adequate intake of food rich in vitamin K. Further work is needed to determine the significance of low vitamin K intake in this population.

Development, Optimization, and Comparison of Different Sample Pre-Treatments for Simultaneous Determination of Vitamin E and Vitamin K in Vegetables.

The absence of vitamin E from the diet can lead to cardiovascular disease, cancer, cataracts, and premature aging. Vitamin K deficiency can lead to bleeding disorders. These fat-soluble vitamins are important nutritional factors that can be determined in different methods in vegetables. In this work, the simultaneous determination of α-tocopherol, α-tocopheryl acetate, phylloquinone, and menaquinone-4 by gas chromatography-mass spectrometry (GC-MS) has been optimized using both direct injection and solid phase microextraction (SPME). Three different sample pre-treatment approaches based on: (A) solid-liquid-liquid-liquid extraction (SLE-LLE), (B) SLE, and (C) SPME were then applied to extract the target analytes from vegetables samples using menaquinone as internal standard. All the procedures allowed the determination of the target analytes in onion, carrot, celery, and curly kale samples. Similar results were obtained with the three different approaches, even if the one based on SPME offers the best performance, together with a reduced use of solvent, time consumption, and experimental complexity, which makes it the preferable option for industrial applications.

Evaluation of vitamin K status and rationale for vitamin K supplementation in dialysis patients.

The cardinal biological role of vitamin K is to act as cofactor for the carboxylation of a number of vitamin K-dependent proteins, some of which are essential for coagulation, bone formation and prevention of vascular calcification. Functional vitamin K deficiency is common and severe among dialysis patients and has garnered attention as a modifiable risk factor in this population. However, no single biochemical parameter can adequately assess vitamin K status. For each biological function of vitamin K, the degree of carboxylation of the relevant vitamin K-dependent protein most accurately reflects vitamin K status. Dephosphorylated uncarboxylated matrix Gla protein (dp-ucMGP) is the best biomarker for vascular vitamin K status when cardiovascular endpoints are studied. Dp-ucMGP levels are severely elevated in haemodialysis patients and correlate with markers of vascular calcification and mortality in some but not all studies. The aetiology of vitamin K deficiency in haemodialysis is multifactorial, including deficient intake, uraemic inhibition of the vitamin K cycle and possibly interference of vitamin K absorption by phosphate binders. The optimal vitamin K species, dose and duration of supplementation to correct vitamin K status in dialysis patients are unknown. Dp-ucMGP levels dose-proportionally decrease with supraphysiological vitamin K2 supplementation, but do not normalize even with the highest doses. In the general population, long-term vitamin K1 or K2 supplementation has beneficial effects on cardiovascular disease, bone density and fracture risk, and insulin resistance, although some studies reported negative results. In haemodialysis patients, several trials on the effects of vitamin K on surrogate markers of vascular calcification are currently ongoing.

Fatty Acids and Fat-Soluble Vitamins in Breast Milk: Physiological Significance and Factors Affecting Their Concentrations.

Fatty acids (FAs) and fat-soluble vitamins are vital components of the human milk lipid fraction. About two-thirds of the human milk FA fraction consist of oleic, linoleic, and palmitic FAs, but the precise composition depends on maternal geography, diet, and genetics. Mothers with high fish consumption have more docosahexaenoic acid (DHA) and other ω-3 FAs in their milk, while mothers with high dairy consumption have more branched-chain FAs in their milk. Vitamins A and E are the most common fat-soluble vitamins, but milk concentrations vary, depending on maternal diet and body stores. Vitamin D is typically low or undetectable in mother's milk and typically fails to meet the infant needs. However, trial data indicate that high maternal supplementation (6,400 IU/day) safely provides nutritionally adequate amounts of vitamin D in her milk. FA and fat-soluble vitamin levels in mother's milk can significantly influence infant health; for example, in preterm infants, low endogenous stores of DHA paired with low levels in maternal milk may influence the risk of chronic lung disease and other inflammatory conditions. Greater attention is warranted to the variation in FA and fat-soluble vitamin content of human milk in relation to infant health.

Quantification of Vitamins A, E, and K and Carotenoids in Submilliliter Volumes of Human Milk.

Background: Human milk is the optimal nutrition for all newborns in the first 6 months of life. In order to assess the nutritional needs of the breastfed infant, human milk is often characterized for multiple nutrients. Objective: To ensure that we minimize the volume of milk dedicated for research and optimize the number of nutrients characterized, we developed analytical methodologies for the determination of vitamins A (retinol), E (alpha and gamma tocopherol), K (phylloquinone and menaquinone-4), and five carotenoids (ß-carotene, lycopene, ß-cryptoxanthin, lutein, and zeaxanthin) using <1 mL human milk. Method: Vitamins E and K and carotenoids are simultaneously isolated from 750 µL milk by liquid-liquid extraction (LLE). Tocopherols and carotenoids are determined by normal-phase LC with fluorescence and ultraviolet detection respectively. Vitamin K is analyzed on the same extracts after resuspension and clean-up by reversed phase liquid chromatography coupled to tandem MS. The analysis of vitamin A involves saponification of 200 µL milk followed by LLE and determination by normal-phase LC with UV detection. Results: Full single-laboratory validation at four different concentration levels is presented. Recovery rates were within 90-105% in all except one case (retinol at 1.9 µg/mL, 88% recovery), with RSDs of repeatability and intermediate reproducibility below 10 and 15%, respectively for all the compounds. Conclusions and Highlights: To the best of best knowledge, this is the first report that allows for the characterization and quantification of vitamins A, E, and K and five carotenoids in <1 mL human milk.

Feeding potentially health promoting nutrients to finishing bulls changes meat composition and allow for product health claims.

Supplementation of feed for bulls with selenium (+50%), vitamin D3 (+300%), vitamin E (+825%), vitamin K3 (+325%) and omega-3 fatty acids (+120%) affected beef nutrient composition. Twelve bulls (½â€¯year old) were randomly allocated to two dietary treatments; control (Con) or supplemented (Sup), and fed 170 days pre-slaughter at an amount of 1% of body weight. Daily gain and feed efficiency were equal in the two groups. Homogenate meat from left forequarter in the Sup group contained more selenium (+26%), vitamin MK4 (+123%), D (+197%), E (+318%), and had lower omega-6/omega-3 ratio (-24%) compared to Con meat. Sup meat fulfilled the requirements to be labelled by health claims and nutrient claims as: "A food item containing a significant amount of selenium, vitamin K and vitamin D". We suggest supplementation of cattle rations during the finishing period as a strategy to increase meat content of specific nutrients important to human health.

[Guidelines for certification of International Normalized Ratio (INR) for vitamin K antagonists monitoring according to the EN ISO 22870 standards]. / Recommandations pour l'accréditation de l'International normalized ratio (INR) pour la surveillance des traitements par antivitamine K en biologie délocalisée selon la norme EN ISO 22870.

Point of care testing (POCT) must comply with regulatory requirements according to standard EN ISO 22870, which identify biologists as responsible for POCT. INR for vitamin K antagonists (VKAs) monitoring is a test frequently performed in haemostasis laboratories. Bedside INR is useful in emergency room, in particular in case of VKAs overdosage but also for specific populations of patients like paediatrics or geriatrics. INR POCT devices are widely used at home by the patients for self-testing, but their use in the hospital by the clinical staff for bedside measurement is growing, with devices which now comply with standard for POCT accreditation for hospital use. The majority of point of care devices for INR monitoring has shown a good precision and accuracy with results similar to those obtained in laboratory. With the aim to help the multidisciplinary groups for POCT supervision, the medical departments and the biologists to be in accordance with the standard, we present the guidelines of the GFHT (Groupe français d'étude sur l'hémostase et la thrombose, subcommittee "CEC et biologie délocalisée") for the certification of POCT INR. These guidelines are based on the SFBC guidelines for the certification of POCT and on the analysis of the literature to ascertain the justification of clinical need and assess the analytical performance of main analysers used in France, as well as on a survey conducted with biologists.