Observational studies have indicated an inverse association between vitamin D levels and the risk of diabetes, yet evidence from population interventions remains inconsistent. PubMed, EMBASE, Cochrane Library and ClinicalTrials.gov were searched up to September 2017. Data from studies regarding serum 25(OH)D, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were pooled. Twenty studies (n = 2703) were included in the meta-analysis. Vitamin D supplementation resulted in a significant improvement in serum 25(OH)D levels (weighted mean difference (WMD) = 33.98; 95%CI: 24.60–43.37) and HOMA-IR (standardized mean difference (SMD) = −0.57; 95%CI: −1.09~−0.04), but not in other outcomes. However, preferred changes were observed in subgroups as follows: short-term (WMD_FBG = −8.44; 95%CI: −12.72~−4.15), high dose (WMD_FBG = −8.70; 95%CI: −12.96~−4.44), non-obese (SMD_{Fasting insulin} = −1.80; 95%CI: −2.66~−0.95), Middle Easterners (WMD_FBG = −10.43; 95%CI: −14.80~−6.06), baseline vitamin D deficient individuals (WMD_FBG = −5.77; 95%CI: −10.48~−1.05) and well-controlled HbA1c individuals (WMD_FBG = −4.09; 95%CI: −15.44~7.27). Vitamin D supplementation was shown to increase serum 25(OH)D and reduce insulin resistance effectively. This effect was especially prominent when vitamin D was given in large doses and for a short period of time, and to patients who were non-obese, Middle Eastern, vitamin D deficient, or with optimal glycemic control at baseline.

The composition of human breast milk is highly variable, and it can be influenced by genetics, diet, lifestyle, and other environmental factors. This study aimed to investigate the impact of geographical location and mode of delivery on the nuclear magnetic resonance spectroscopy (NMR) metabolic profile of breast milk and its relationship with the milk microbiome. Human milk metabolic and microbiota profiles were determined using NMR and 16S rRNA gene sequencing, respectively, in 79 healthy women from Finland, Spain, South Africa, and China. Up to 68 metabolites, including amino acids, oligosaccharides, and fatty acid-associated metabolites, were identified in the milk NMR spectra. The metabolite profiles showed significant differences between geographical locations, with significant differences (p < 0.05) in the levels of galactose, lacto-N-fucopentaose III, lacto-N-fucopentaose I and 2-fucosyllactose, 3-fucosyllactose, lacto-N-difucohexaose II, lacto-N-fucopentaose III, 2-hydroxybutyrate, 3-hydroxybutyrate, proline, N-acetyl lysine, methyl-histidine, dimethylamine, kynurenine, urea, creatine and creatine phosphate, formate, lactate, acetate, phosphocholine, acetylcholine, LDL, VLDL, ethanolamine, riboflavin, hippurate, spermidine, spermine and uridine. Additionally, the effect of caesarean section on milk metabolome was dependent on the geographical region. Specific interrelations between human milk metabolites and microbiota were also identified. Proteobacteria, Actinobacteria, and Bacilli were most significantly associated with the milk metabolites, being either positively or negatively correlated depending on the metabolite. Our results reveal specific milk metabolomic profiles across geographical locations and also highlight the potential interactions between human milk’s metabolites and microbes.

Increased prevalence of metabolic syndrome (MetS) has become a global major public health problem. Chronic low-grade inflammation associated with diet was found to play an import role in the development of MetS, although further studies are needed. The main purpose of this study was to explore the association between the dietary inflammatory index (DII), C-reactive protein (CRP) as a sign of inflammation status, and MetS. A total of 1712 participants from eight cities in China were included. Sociodemographic and health-related information was collected by a self-administrated questionnaire. Anthropometric information and fasting blood samples were collected for identification of MetS. DII scores were computed based on one time 24-h dietary recall. No significant association between MetS and DII was observed except for the blood pressure component of MetS (OR _{T3 versus T1} = 1.40; 95% CI: 1.03 to 1.89). A significant increased prevalence for MetS was observed for higher CRP (OR = 1.66; 95% CI: 1.26 to 2.18), as well as four out of five of MetS components. In stratified analyses by sex, the associations between DII/CRP and MetS among women, but not men, are comparable to the whole sample. In addition, Both the 2nd and 3rd tertile of the DII had a higher CRP level (β-Coefficients _{T2 versus T1} = 0.086, 95% CI: 0.004 to 0.167; β-Coefficients _{T3 versus T1} = 0.145, 95% CI: 0.045 to 0.245) among subjects with MetS. Participants with higher DII scores reported a higher degree of “Shanghuo” (p = 0.007), which is a traditional concept characterized by “redness, swelling, fever and pain” in Chinese Medicine. This study suggested a close association between CRP and MetS, while the association between the DII and MetS was limited. DII was only specifically associated with CRP at a higher level among participants with MetS.

Foxtail millet has relatively low starch digestibility and moderate glycemic index compared to other grains. Since there are still no clinical researches regarding its long-term effect on blood glucose, this self-controlled study was conducted to investigate the glucose-lowering effect of foxtail millet in free-living subjects with impaired glucose tolerance (IGT). Fifty g/day of foxtail millet was provided to enrolled subjects throughout 12 weeks and the related clinical parameters were investigated at week 0, 6 and 12, respectively. After 12 weeks of foxtail millet intervention, the mean fasting blood glucose of the subjects decreased from 5.7 ± 0.9 mmol/L to 5.3 ± 0.7 mmol/L (p < 0.001) and the mean 2 h-glucose decreased from 10.2 ± 2.6 mmol/L to 9.4 ± 2.3 mmol/L (p = 0.003). The intake of foxtail millet caused a significant increase of serum leptin (p = 0.012), decrease of insulin resistance (p = 0.007), and marginal reduction of inflammation. Furthermore, a sex-dependent difference in glucose-lowering effect of foxtail millet was observed in this study. Foxtail millet could improve the glycemic control in free-living subjects with IGT, suggesting that increasing the consumption of foxtail millet might be beneficial to individuals suffering from type 2 diabetes mellitus.

Previous studies have demonstrated the importance of eating behaviour regarding dietary variety and nutrient intake of children. However, the association between picky eating and growth of children is still a topic of debate. This study sought to estimate the prevalence of picky eating and to identify possible associations with the growth of school-age children in China. In this survey, 793 healthy children aged 7-12 years were recruited from nine cities and rural areas in China using a multi-stage cluster sampling method. Data collected included socio-demographic information and parents' perceptions of picky eating using a structured questionnaire, nutrient intake using 24-hour dietary recall, weight and height using body measurements, and intelligence using the Wechsler Intelligence Scale for Children. Blood samples were collected and analysed for minerals. The prevalence of picky eating reported by parents was 59.3% in children. Compared with non-picky eaters, picky eaters had a lower dietary intake of energy, protein, carbohydrates, most vitamins and minerals, and lower levels of magnesium, iron, and copper in the blood (p < 0.05), and also had a 0.184 z-score lower in height for age (95% CI: -0.332, 0.036; p = 0.015), a 0.385 z-score lower in weight for age (95% CI: -0.533, -0.237; p < 0.001), a 0.383 z-score lower in BMI for age (95% CI: -0.563, -0.203; p < 0.001), and scored 2.726 points higher on the intelligence test (95% CI: 0.809, 4.643; p = 0.006) when adjusted for children's birth weight and food allergy, mothers' education, and family income. Picky eating behaviour towards meat, eggs and vegetables showed negative associations with growth. Picky eating behaviour is prevalent in school-age children in China and may have a negative effect on growth.

Fatty acids (FA), phospholipids (PL), and gangliosides (GD) play a central role in infant growth, immune and inflammatory responses. The aim of this study was to determine FA, PL, and GD compositional changes in human milk (HM) during lactation in a large group of Chinese lactating mothers (540 volunteers) residing in Beijing, Guangzhou, and Suzhou. HM samples were collected after full expression from one breast and while the baby was fed on the other breast. FA were assessed by direct methylation followed by gas chromatography (GC) analysis. PL and GD were extracted using chloroform and methanol. A methodology employing liquid chromatography coupled with an evaporative light scattering detector (ELSD) and with time of flight (TOF) mass spectrometry was used to quantify PL and GD classes in HM, respectively. Saturated FA (SFA), mono-unsaturated FA (MUFA), and PL content decreased during lactation, while polyunsaturated FA (PUFA) and GD content increased. Among different cities, over the lactation time, HM from Beijing showed the highest SFA content, HM from Guangzhou the highest MUFA content and HM from Suzhou the highest n-3PUFA content. The highest total PL and GD contents were observed in HM from Suzhou. In order to investigate the influence of the diet on maternal milk composition, a careful analyses of dietary habits of these population needs to be performed in the future.