Inmaculada Blanco-Navarro

Lutein bioavailability from lutein ester-fortified fermented milk: in vivo and in vitro study☆☆☆

We assessed the bioavailability of lutein from lutein-fortified fermented milk using in vivo and in vitro approaches. Twenty-four volunteers were randomized to take lutein-fortified fermented milk at two levels of fortification. Single-dose bioavailability study (2x100 ml, ca. 8 or 16 mg of lutein) was performed using a three-point approach (baseline, 3.5 and 6.5 h). Multiple-dose study consisted of consuming one serving/day (ca. 4 or 8 mg/100 ml) for 14 days. Blood samples for biochemical, hematological and lutein analysis were drawn at baseline, Day 7 and Day 14. In vitro bioaccessibility was assessed by a static gastrointestinal digestion model. Lutein content, in vitro ester hydrolysis and micellarization, and lutein concentrations achieved in serum were analyzed by HPLC. In vivo, post-prandial response was higher using the high content fermented milk, but the percentage of absorption was not different according to the dose consumed. Net increments at Day 7 and Day 14 were significantly higher on consuming the high-dose milk as well. In vitro, lutein ester hydrolysis was incomplete regardless of the amount initially present. Free lutein released was higher using the high-dose fermented milk, but the percentage of hydrolysis was similar at both levels of fortification. In the micellar phase, the percentage of free and total lutein was not different according to the dose. Our results support the suitability of the fermented milk as a carrier of lutein esters and an in vivo dose-dependent effect upon regular consumption and suggest the usefulness of in vitro models to provide relevant information to predict in vivo responses.

Bioavailability of β-cryptoxanthin in the presence of phytosterols: in vitro and in vivo studies.

Bioactive compounds are used in the design and development of new food products with potential health benefits, although little is known regarding their bioavailability and interactions. This study assessed the stability, in vitro bioaccessibility, and human bioavailability of β-cryptoxanthin from β-cryptoxanthin-rich drinks with and without added phytosterols developed for this purpose. The developed drinks showed no difference in the content of β-cryptoxanthin, and they were stable over 6 months. In vitro, hydrolysis of β-cryptoxanthin esters and the amount of free β-cryptoxanthin at duodenal and micellar phases were similar regardless of the presence of phytosterols. In the human study, the daily intake provoked significant increments of β-cryptoxanthin in serum regardless of the type of the drink. In conclusion, in vitro and in vivo human studies have shown that the bioavailability of β-cryptoxanthin is not significantly affected by the presence of phytosterols when they are simultaneously supplied in a drink.

The prevalence of vitamin deficiency in clinical practice is assay-dependent.

BACKGROUND & AIM Vitamin D deficiency is an important concern in clinical settings and recently, international agencies have recognised the importance of 25-OHD assays in defining vitamin D status. Thus, our aim was to assess the consistency of different vitamin D assays in clinical practice. METHODS 25-OH-vitamin D was measured in 332 patients by ultra-fast liquid chromatography (UHPLC) and two immunoassays (Liaison Total 25(OH) and ADVIA Centaur Vitamin D Total Assay). Samples from the Vitamin D External Quality Survey (DEQAS) and the Standard Reference Material SRM 972 were used for analytical quality control. RESULTS All methods displayed an acceptable performance with DEQAS samples but immunoassays showed a significant bias against certified materials. Compared to UHPLC, differences were significant for both immunoassays in the deficiency interval but the systematic bias was higher for the ADVIA assay throughout the whole range of concentrations. CONCLUSION The prevalence of vitamin D deficiency in clinical practice is assay-dependent and physicians should be aware of the uncertainty associated with vitamin D assessment.

Seasonal variation of serum α- and β-cryptoxanthin and 25-OH-vitamin D3 in women with osteoporosis

Summaryβ-Cryptoxanthin displays a unique anabolic effect on bone calcification. In women with osteoporosis, serum β-cryptoxanthin and 25-OH-vitamin D3 showed a weak but significant correlation and exhibited a complementary seasonal distribution. The potential role of β-cryptoxanthin as a nutritional approach to improving bone health deserves further evaluation.IntroductionDietary intake and serum levels of β-cryptoxanthin have been inversely related to different bone and joint disorders and in vitro and animal studies have shown that β-cryptoxanthin displays a unique anabolic effect on bone calcification. Due to the emerging role of β-cryptoxanthin in bone biology, we aimed to assess the serum distribution and variability of β-cryptoxanthin and their potential relation to 25-OH-vitamin D3 in women with osteoporosis.MethodsSerum concentrations of α- and β-cryptoxanthin and 25-OH- D3 in women with osteoporosis (N = 644) were analyzed using a quality-controlled high-performance liquid chromatography (HPLC) method.ResultsOverall, significant seasonal variations were found for the three analytes and inter-individual variation was also high (60–73%). β-cryptoxanthin and 25-OH-vitamin D3 exhibited a marked complementary seasonal distribution in serum, with vitamin D displaying the highest values in summer and β-cryptoxanthin in winter.ConclusionsGiven the anabolic effect of β-cryptoxanthin on bone calcification and its complementary seasonal distribution with respect to 25-OH-vitamin D3, the potential role of β-cryptoxanthin as a sustainable nutritional approach to improving bone health deserves to be further evaluated.

Modulation of DNA-induced damage and repair capacity in humans after dietary intervention with lutein-enriched fermented milk.

Dietary factors provide protection against several forms of DNA damage. Additionally, consumer demand for natural products favours the development of bioactive food ingredients with health benefits. Lutein is a promising biologically active component in the food industry. The EFSA Panel on Dietetic Products, Nutrition and Allergies considers that protection from oxidative damage may be a beneficial physiological effect but that a cause and effect relationship has not been established. Thus, our aim was to evaluate the safety and potential functional effect of a lutein-enriched milk product using the Comet Assay in order to analyze the baseline, the induced DNA-damage and the repair capacity in the lymphocytes of 10 healthy donors before and after the intake of the mentioned product. Our data suggest that the regular consumption of lutein-enriched fermented milk results in a significant increase in serum lutein levels and this change is associated with an improvement in the resistance of DNA to damage and the capacity of DNA repair in lymphocytes. Our results also support the lack of a genotoxic effect at the doses supplied as well as the absence of interactions and side effects on other nutritional and biochemicals markers.

Analysis of microsamples of human faeces: a non-invasive approach to study the bioavailability of fat-soluble bioactive compounds

IntroductionBioavailability is a critical feature in the assessment of the role of micronutrients in human health. Poorly bioavailable micronutrients like carotenoids may reach significant concentrations in the gastrointestinal tract where they may exert biological actions.PurposeWe evaluated a simple collection protocol to determine vitamin A, E and carotenoids in microsamples of human faeces as a non-invasive approach for nutritional studies.MethodsMicrosamples of human faeces were collected using a commercially available device, extracted and analysed on two LC systems. Suitability of the protocol was assessed by evaluating several factors including the effect of simulated colonic conditions and two nutritional scenarios with different dietary components, chemical forms, nutritional goals and target groups.ResultsThe protocol was reproducible and representative of a faeces sample. The major dietary and serum carotenoids, and several “unidentified” compounds (possibly metabolites) could be detected, and cis-/trans-β-carotene profile reflected dietary intervention. In faeces of neonates, free retinol, retinyl and α-tocopheryl acetate (from infant formula), long-chain fatty acid retinyl esters (from human milk), free γ-tocopherol and α-tocopherol could be detected.ConclusionOur results show that the analysis of vitamin A, E and carotenoids in microsamples of human faeces is a suitable, non-invasive approach that may provide relevant information regarding responsiveness, nutrient stability and metabolism and may help assess adequacy of chemical forms and delivery systems reaching the colon.

Criteria of adequacy for vitamin D testing and prevalence of deficiency in clinical practice.

Abstract Background: Vitamin D deficiency is an important concern in clinical settings although there is no consensus on who should undergo 25-OH-vitamin D testing. We studied the prevalence of vitamin D deficiency before and after introducing adequacy (clinical and biochemical) criteria for testing. Methods: A total of 32,363 tests for 25-OH-vitamin D were retrospectively evaluated. Requests were unrestricted until December 2010 and justification criteria were applied from January 2011. During 6 years, 25,656 samples were analyzed (UHPLC) of which 12,315 were considered the first visit. The prevalence of deficiency was assessed for all the samples and according to the year, sex, season, age, origin of the requests, inclusion of adequacy criteria and consecutive visits. Results: A significant proportion of the requests (25%) were unjustified and less than half of the clinically or biochemically-justified tests displayed serum concentrations indicative of deficiency. Application of adequacy criteria resulted in a non-significant increase in the prevalence of deficiency, both at the first visit (36.5 vs. 41.7, p=0.17) and for all the samples analyzed (32.0 vs. 35.5, p=0.14). The percentage of deficiency decreased in consecutive visits although 2/3 and 41% of the patients remained deficient on the second and third visit, respectively. Moreover, at least 1/5 of sufficient patients at the first test became deficient in subsequent evaluations. Conclusions: A significant proportion of the requests was unjustified by clinical or biochemical criteria. Our data also indicate that clinical and biochemical criteria may be necessary (to be present) to justify vitamin D testing but not sufficient (predictive) to indicate the presence of vitamin D deficiency.

Chapter 21:Simultaneous Ultra-high-performance Liquid Chromatography for the Determination of Vitamin A and Other Fat-soluble Vitamins to Assess Nutritional Status

Diet constitutes a key modifiable factor in the development and maintenance of health. Malnutrition (both over- and under-nutrition) plays a critical role in morbidity and mortality, and therefore the evaluation of nutritional status is a key point to improve the health of the individuals and popula...