Evidence is accumulating that vitamin D may have beneficial effects on respiratory tract, autoimmune, neuro-degenerative, and mental diseases. The present umbrella review of systematic reviews (SRs) of cohort studies and randomised controlled trials (RCTs), plus single Mendelian randomisation studies aims to update current knowledge on the potential role of vitamin D in preventing and treating these extraskeletal diseases. Altogether, 73 SRs were identified. Observational data on primary prevention suggest an inverse association between vitamin D status and the risk of acute respiratory tract infections (ARI), dementia and cognitive decline, and depression, whereas studies regarding asthma, multiple sclerosis (MS), and type 1 diabetes mellitus (T1DM) are scarce. SRs of RCTs support observational data only for the risk of ARI. No respective RCTs are available for the prevention of chronic obstructive pulmonary disease (COPD), MS, and T1DM. SRs of RCTs indicate beneficial therapeutic effects in vitamin D-deficient patients with asthma and COPD, while effects on major depression and T1DM need to be further elucidated. Mendelian randomisation studies do not consistently support the results of SRs. Since several limitations of the included SRs and existing RCTs do not permit definitive conclusions regarding vitamin D and the selected diseases, further high-quality RCTs are warranted.

We investigated whether macronutrient composition of energy-restricted diets influences the efficacy of a telemedically guided weight loss program.

The degradation of muscle mass and loss of functional proteins due to catabolism are associated with adverse outcomes in critically ill patients. While an adequate supply of protein within a medical nutrition concept is suggested to minimize proteolysis, the specificities on appropriate dosage and timing are still under debate. The current study aimed to evaluate the effect of two different quantities of protein as part of a standardized energetically controlled nutrition therapy for the preservation of muscle mass in the later phase of critical illness. A randomized controlled trial was conducted in 42 critically ill patients (age 65 ± 15; 12 females; SAPS 45 ± 11; TISS 20 ± 7; SOFA-score 7 ± 3). The subjects were randomly assigned to either the intervention (1.8 g protein/kg body weight [BW]/d) or standard (1.2 g protein/kg BW/d) group. Nutrient supply via enteral and/or parenteral nutrition was calculated based on the individual energy expenditure measured by indirect calorimetry and target protein content. Quadriceps muscle layer thickness (QMLT) was observed through sonography at inclusion, and during the follow-up period, two and four weeks after inclusion. The measurement points were fixed on two sides at the midpoint and two-thirds between the anterior superior iliac spine and top of the patella. The data were analyzed descriptively wherein chi-squared tests or unpaired two-samle t-tests checked group differences. Daily changes in muscle mass were estimated using a linear mixed model. All data are shown as the mean ± standard deviation (SD). Actual protein intake reached 1.5 ± 0.5 g and 1.0 ± 0.5 g/kg BW/d in the intervention and standard group, respectively. Mean values of all measurements of QMLT at inclusion (day 13 ± 2 after ICU admission) were 13.5 ± 7.4 mm and 13.4 ± 7.1 mm in the intervention and standard group, respectively (P = 0.967). In both the groups, QMLT decreased over time (P < 0.001), while the estimated mean values of daily QMLT changes were -0.15 ± 0.08 mm (intervention) and -0.28 ± 0.08 mm (standard) without significant between-group differences (intervention effect, P = 0.368; time x intervention effect, P = 0.242). Illness scores and clinical outcomes showed no group differences. In this single-center trial the increased amounts of protein (1.5 g vs. 1.0 g/kg BW/d) provided through medical nutrition therapy in the late phase of critical illness did not achieve a statistically significant impact on the loss of muscle mass in long-term immobilized ICU patients. Larger multi-center trials are needed to evaluate whether observed numerical differences in muscle mass could be a true finding, and will translate into improved clinical outcomes. German Clinical Trials Register (http://www.drks.de/), DRKS-ID: DRKS00013594.

Flavan-3-ols are the main contributors to polyphenol intake. Many varying beneficial health effects in humans have been attributed to them, including the prevention of cardiovascular disease and cancer. Nevertheless, the mechanisms by which these flavonoids could exert beneficial functions are not entirely known. Several in vitro studies and in vivo animal models have tried to elucidate the role of the specific colonic metabolites on the health properties that are attributed to the parent compounds since a larger number of ingested flavan-3-ols reach the colon and undergo there microbial metabolism. Many new studies about this topic have been performed over the last few years and, to the best of our knowledge, no scientific literature review regarding the bioactivity of all identified microbial metabolites of flavan-3-ols has been recently published. Therefore, the aim of this review is to present the current status of knowledge on the potential health benefits of flavan-3-ol microbial metabolites in humans while using the latest evidence on their biological activity.