The aim of this systematic review was to assess the effect of vitamin D supplementation on glucose and insulin metabolism in overweight and obese subjects. The search process was based on the selection of publications listed in the databases: PubMed, Scopus, Web of Knowledge, Embase and the Cochrane library that met the inclusion criteria. Twelve randomized controlled trials were included. The analysed population consisted of 1181 individuals with BMIs >23 kg/m2. Changes in the concentration of 25(OH)D, fasting glucose, insulin and the HOMA-IR index were assessed. In the meta-regression analysis, a restricted maximum likelihood method was applied. To combine individual study results, a meta-analysis was performed. Vitamin D supplementation did not have an effect on glucose concentrations, insulin level and HOMA-IR values when the supplemented dose, time of supplementation and baseline of 25(OH)D concentration were taken under consideration in subgroup-analysis. This meta-analysis provides evidence that vitamin D supplementation has no significant effect on glucose and insulin metabolism in overweight and obese individuals.

This meta-analysis suggests that supplementation with vitamin D does not have a significant influence on changes in the concentration of selected inflammatory biomarkers in the obese and overweight subjects.

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Background The oral microbiota is a significant risk indicator for oral diseases, such as dental caries and periodontal inflammation. Much attention is presently paid to the development of functional foods (e.g. beverages containing cranberry constituents, or foods containing probiotics) that may serve as adjuncts for oral disease treatments (e.g. periodontitis and caries). Cranberry fruit, due to its unique chemical composition and antimicrobial potential, is a possible ingredient of such foods. The study aimed to investigate the effects of cranberry juice (CJ) and a cranberry functional beverage (mixture of 80% v/v apple juice, 20% v/v cranberry juice, and 0.25 g/100 mL ground cinnamon; CFB) on the growth and metabolic activity of selected oral bacteria. Methods Serial dilution pour plate method (SDPP) was used to examine the effect of CJ and CFB on the growth of Actinomyces naeslundii, Streptococcus mutans, and Lactobacillus paracasei subsp. paracasei. 48-h electrical impedance measurements (EIM) during the cultivation of A. naeslundii were applied to evaluate the utility of the method as a rapid alternative for the assessment of the antimicrobial potential of cranberry beverages. Results The tested bacteria differed in their susceptibility to the antimicrobial action of CJ and CFB, with L. paracasei subsp. paracasei being least vulnerable to CFB (according to SDPP). Although CJ at a concentration of 0.5 mL/mL, showed a bactericidal effect on the growth of S. mutans, A. naeslundii was more sensitive to CJ (SDPP). Its inhibitory effect on A. naeslundii was seen even at concentrations as small as 0.03125–0.125 mL/mL (SDPP and EIM). On the other hand, S. mutans seemed to be more vulnerable to CFB than A. naeslundii (SDPP). Conclusions CFB may be considered an adjunct in the treatment of oral diseases due to its action against selected oral pathogens, and not against the presumably beneficial L. paracasei subsp. paracasei. Bioelectrical impedance measurements appear to be a quick alternative to evaluating the antimicrobial activity of fruit beverages, but their utility should be confirmed with tests on other bacteria.

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Bovine colostrum (BC) is a promising natural product applied to improve immunological functions. However, there is very little evidence on the true benefits of BC treatment on the immune function of trained and physically active people; moreover, there is no consensus on the supplementation strategy. For this reason, the aim of this meta-analysis was to quantify the effects of BC supplementation on immunological outcomes in physically active people. Data from 10 randomised controlled trials (RCTs) investigating the effect of BC supplementation in athletes and physically active adults were analysed, involving 239 participants. The results show that BC supplementation has no or a fairly low impact on improving the concentration of serum immunoglobulins (IgA, IgG), lymphocytes and neutrophils, and saliva immunoglobulin (IgA) in athletes and physically active participants. Previous research has shown BC to reduce upper respiratory tract infections; nevertheless, there is a gap of scientific knowledge on the mechanisms underlying these effects. Future RCTs are needed to focus on finding these mechanisms, as well as on preparing a clear consensus on a BC supplementation strategy in trained athletes and the physically active population.

BackgroundFrom the viewpoint of human physiological adaptability, we previously investigated seasonal variation in the amount of unabsorbed dietary carbohydrates from the intestine after breakfast in Japanese, Polish and Thai participants. In this investigation we found that there were significant seasonal variations in the amount of unabsorbed dietary carbohydrates in Japanese and Polish participants, while we could not find significant seasonal variation in Thai participants. These facts prompted us to examine seasonal variations in the respiratory quotient after an overnight fast (an indicator of the ratio of carbohydrate and fat oxidized after the last meal) with female university students living in Osaka (Japan), Poznan (Poland) and Chiang Mai (Thailand).MethodsWe enrolled 30, 33 and 32 paid participants in Japan, Poland and Thailand, respectively, and measurements were taken over the course of one full year. Fasting respiratory quotient was measured with the participants in their postabsorptive state (after 12 hours or more fasting before respiratory quotient measurement). Respiratory quotient measurements were carried out by means of indirect calorimetry using the mixing chamber method. The percent body fat was measured using an electric bioelectrical impedance analysis scale. Food intake of the participants in Osaka and Poznan were carried out by the Food Frequency Questionnaire method.ResultsThere were different seasonal variations in the fasting respiratory quotient values in the three different populations; with a significant seasonal variation in the fasting respiratory quotient values in Japanese participants, while those in Polish and Thai participants were non-significant. We found that there were significant seasonal changes in the percent body fat in the three populations but we could not find any significant correlation between the fasting respiratory quotient values and the percent body fat.ConclusionsThere were different seasonal variations in the fasting respiratory quotient values in the three different populations. There were significant seasonal changes in the percent body fat in the three populations but no significant correlation between the fasting respiratory quotient values and the percent body fat.

Purpose. The purpose of the study was to evaluate the accuracy of three non-calorimetric methods' measurements of energy expenditure (EE) in laboratory conditions and to compare the results obtained by each method in free-living condition in a group of adult subjects. Methods. Measurement was performed on 20 individuals aged 19-39 years. An assessment of EE at different intensities of physical activity was conducted by: monitoring heart rate with a S-610 Polar Sport Tester (HrM), measuring body movement by an ActiGraph GT1M accelerometer (AM), and recording METs (Mr) by a physical activity questionnaire, for different activities (leisure and exercise) at various intensities in laboratory and free-living conditions. Indirect calorimetry (Cosmed K4b2 respirometer) was used as a reference standard. Results. The most reliable tool for EE assessment was HrM (100% accurate). AM overestimated EE (about 60%) for activity at moderate-intensity and underestimated EE (about 40%) at vigorous-intensity. Mr overestimated the results, with measurement errors increasing with an increase in physical activity intensity (about 40-120%). Conclusions. Although AM and Mr provided less accurate results than HrM in laboratory conditions, there were no significant differences between the three methods (HrM, AM and Mr) when total daily energy expenditure was calculated for the participants in free-living condition.