Objective:This study aimed to investigate possible serum 25-hydroxyvitamin D [25(OH)D] cutoffs for the associations between 25(OH)D and Bone turnover markers (BTMs), and how GC gene variation influences such cutoffs in Chinese women of childbearing age. Methods:In total, 1,505 non-pregnant or non-lactating women (18-45 years) were recruited from the 2015 Chinese Adult Chronic Disease and Nutrition Surveillance. Serum 25(OH)D, osteocalcin (OC), procollagen type 1 N-terminal propeptide (P1NP), β-CrossLaps of type 1 collagen containing cross-linked C-telopeptide (β-CTX), and single nucleotide polymorphisms were determined. Locally weighted regression and smoothing scatterplot and segmented regression were performed to estimate the 25(OH)D thresholds. Results:The median serum 25(OH)D was 16.63 (11.96-22.55) ng/mL and the prevalence of low serum 25(OH)D (< 12 ng/mL) was 25.2%. Women with the lowest 25(OH)D had the highest β-CTX. After adjustment for the confounders, 25(OH)D cutoffs for OC [14.04 (12.84-15.23) ng/mL], β-CTX [13.94 (12.49-15.39) ng/mL], and P1NP [13.87 (12.37-15.37) ng/mL] in the whole population, cutoffs for OC [12.30 (10.68-13.91) ng/mL], β-CTX [12.23 (10.22-14.23) ng/mL], and P1NP [11.85 (10.40-13.31) ng/mL] in women with the GC rs2282679 G allele, and cutoffs for OC [12.75 (11.81-13.68) ng/mL], β-CTX [13.05 (11.78-14.32) ng/mL], and P1NP [12.81 (11.57-14.06) ng/mL] in women with the GC rs2282679 T allele, were observed. Below these cutoffs, BTMs were negatively associated with 25(OH)D, while above these cutoffs, BTMs plateaued. Conclusion:In Chinese women of childbearing age, there were thresholds effect of serum 25(OH)D concentrations on BTMs. The results indicated that serum 25(OH)D concentrations < 13.87 ng/mL in this population had adverse influences on maintaining bone remodeling. BTMs were suppressed at a relatively lower serum 25(OH)D in women with the GC rs2282679 G allele compared with those with the T allele.

Background/Objectives: Subnormal folate levels have a detrimental impact on the growth and development of preschoolers. We aimed to investigate the association between independent/synergistic effects of the gene polymorphisms (methyltetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms, alongside methionine synthase reductase (MTRR) A66G polymorphism and the methionine synthase (MTR) A2756G polymorphism) and serum folate levels as well as cognitive levels in Chinese preschoolers aged 5-7 years. Methods: Data were sourced from 614 children, acquired through the "Long-term Health Effects Assessment Project of Infants and Toddlers Nutritional Pack (LHEAITNP)" program were used. Folate serum concentrations were measured using a microbiologically modified technique. The genotypes of MTHFR A1298C and C677T, together with MTRR A66G, were identified by Kramer's Allele-Specific PCR (KASP) technique. The cognitive scores of children were assessed by questionnaire. Results: MTHFR 677TT and MTR 2756AG + GG correlated negatively with serum folate levels (TT vs. CC + CT, p = 0.0009 and AG + GG vs. AA, p = 0.0057, respectively). MTHFR C677T and A1298C were independently linked to an elevated risk of suboptimal cognitive development (TT vs. CC + CT, p = 0.0009 and AA vs. CA + CC, p < 0.0001, respectively). The joint impact of these risk genotypes showed significantly increased risk of folate deficiency and inferior cognitive function compared to non-risk genotypes, particularly in those with more than two risk genotypes. The findings were corroborated by a cumulative effects model (p < 0.05). Conclusions: Our results indicate the substantial association between folate-homocysteine metabolism gene variants and serum folate status/cognitive performance in Chinese preschoolers. Potential gene-nutrient interactions worthy of longitudinal investigation.

OBJECTIVE:Discussion on the effects of edible oils with different fatty acid compositions on glucose and lipid metabolism in middle-aged and elderly rats under free-feeding conditions with a fat energy ratio of 35%. METHODS:The experiment randomized 50 male rats aged 8-10 months into five groups: a control group(NC, fed AIN93 M diet), a monounsaturated fatty acid(MUFA) group(fed high oleic sunflower oil diet), a polyunsaturated fatty acid(PUFA) group(fed regular sunflower oil diet), an animal-based saturated fatty acid(ASFA) group(fed lard diet), and a vegetable-based saturated fatty acid(VSFA) group(fed coconut oil diet). The rats were fed continuously for 12 weeks. During the experiment, the body weight and food intake of the rats were measured weekly. At the end of the 12th week, an oral glucose tolerance test was performed on the rats. After the experiment, dual-energy X-ray absorptiometry(DEXA) was used to measure the body fat and abdominal fat content of the rats. Blood samples were collected from the abdominal aorta for the determination of fasting blood glucose and blood lipid levels. The perirenal fat and epididymal fat of rats were removed and weighed, and the ratios of these fat masses to the body weight were calculated respectively. Additionally, HE staining was used to observe the liver pathological lipids of the rats. RESULTS:Body weight and food intake result showed that compared to the NC group, the total food intake of rats in all four experimental groups decreased. The energy intake of the VSFA group and the energy utilization of the PUFA and VSFA groups increased, with these differences being statistically significant(P&lt;0.05). In terms of blood lipid levels, compared to the NC group, the the triglyceride(TG) level in the MUFA group decreased, while the TG, total cholesterol, high density lipoprotein cholesterol(HDL-C), nonesterified fatty acid(NEFA)and Non-HDL-C levels in the PUFA group significantly decreased. The HDL-C and NEFA levels in the ASFA group also decreased, and the low density lipoprotein cholesterol(LDL-C) level in the VSFA group significantly decreased, all with statistically significant differences(P&lt;0.01 or P&lt;0.05). In terms of blood glucose levels, the FBG levels of rats in the PUFA and ASFA groups were lower than in the NC group(P&lt;0.05). The perirenal and epididymal fat masses of rats in the MUFA and VSFA groups were higher than those in the control group(P &lt; 0.01, P &lt; 0.05). The perirenal fat mass of rats in the ASFA group was higher than that in the NC group(P&lt;0.05). The abdominal and total body fat content of rats in the MUFA group was significantly higher than in the NC group(P&lt;0.01, P&lt;0.05). Hepatic histopathological result showed that the lipid vacuoles in the liver of the VSFA group were significantly more than in the NC group, while that in the other groups were between the two. CONCLUSION:Under the condition of ad libitum feeding and a fat energy contribution ratio of 35%, PUFA oil are beneficial for improving glucose and lipid metabolism levels, thereby potentially reducing the risk of cardiovascular disease. MUFA oil may lead to an increase in abdominal and overall body fat in rats, ASFA oil may help lower blood glucose levels, while VSFA oil may exacerbate the accumulation of liver fat in rats.

ObjectiveThe free hormone hypothesis suggests that free and bioavailable 25-hydroxyvitamin D [25(OH)D] may better reflect vitamin D bioactivity. This study aimed to determine the free and bioavailable 25(OH)D characteristics, estimate their thresholds based on parathyroid hormone (PTH) and bone turnover markers (BTMs), assess their associations with the risk of metabolic syndrome (MetS), and evaluate their potential advantages.MethodsA cross-sectional study was conducted using a nationally representative database (n = 1,505, female, 18–45 years). Serum total 25(OH)D, vitamin D-binding protein, albumin, PTH, and BTMs [osteocalcin, β-CrossLaps of type 1 collagen containing cross-linked C-telopeptide (β-CTX), and procollagen type 1 N-terminal propeptide (P1NP)] were measured. Free 25(OH)D and bioavailable 25(OH)D were calculated. The threshold associations of 25(OH)D with PTH and BTMs were analyzed. The relationship between 25(OH)D and MetS risk was examined. An intervention study was then performed in 39 women (18–47 years) to assess the associations of increasing 25(OH)D with PTH and BTMs after vitamin D supplementation.ResultsIn the cross-sectional study, the three forms of 25(OH)D were found to have similar distribution characteristics. Free and bioavailable 25(OH)D correlated well with total 25(OH)D. Significant total 25(OH)D cutoffs were observed for PTH (14.19 ng/mL and 18.03 ng/mL), osteocalcin (15.14 ng/mL), β-CTX (14.79 ng/mL), and P1NP (15.08 ng/mL). Free and bioavailable 25(OH)D cutoffs were only found for P1NP (3.47 pg/mL and 1.66 ng/mL, respectively). A total 25(OH)D of <15.14 ng/mL was marginally associated with a higher risk of reduced high-density lipoprotein cholesterol (HDL-C) [odd ratios (OR) = 1.371 (0.991–1.899)]. The ORs of higher versus lower free and bioavailable 25(OH)D levels for reduced HDL-C were 0.770 (0.621–0.956) and 0.772 (0.622–0.958), respectively. The results of the intervention study indicated that PTH and BTMs responded more sensitively to total 25(OH)D than to free or bioavailable 25(OH)D.ConclusionFree and bioavailable 25(OH)D only had a threshold effect on P1NP. The active 25(OH)D thresholds could be used for risk assessment of reduced HDL-C. However, no superiority of free or bioavailable 25(OH)D was found based on the response of PTH and BTMs to changes in 25(OH)D in Chinese women of childbearing age following vitamin D supplementation.Clinical trial registrationhttp://www.chictr.org.cn, ChiCTR2200058290.

Objective: To analyze the associations between serum 25(OH)D levels and the risk of metabolic syndrome (MetS) and its components, and the related genetic and non-genetic factors in non-diabetic women of childbearing age in China. Methods: Subjects were randomly selected from the 2015 Chinese Adult Chronic Disease and Nutrition Surveillance. The data of sociodemographic characteristics and lifestyle factors were obtained through questionnaire survey. Anthropometry was measured by trained interviewers, and fasting blood was collected to test 25-hydroxyvitamin D [25(OH)D], total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), and other related parameters. Generalized linear mode and multivariate logistic analysis were performed to analyze the associations between serum 25(OH)D and MetS and its components, adjusting for the possible confounders. Results: Body mass index (BMI), serum alanine aminotransferase (ALT), hypersensitive C-reactive protein (hs-CRP), 25(OH)D, phosphorus (P), and parathyroid hormone (PTH) levels were associated with the number of MetS’s components. G allele carriers of GC rs2282679 had higher diastolic blood pressure (DBP) and FBG levels compared with the TT genotypes, while higher genetic risk score (GRS) seemed to be associated with reduced HDL-C level. The odds ratio (OR) for MetS in lowest group of 25(OH)D was 1.533 (0.980–2.399) after adjusting for season, district, area type, latitude, age, BMI, PTH, P, ALT, CRE, interleukin-6 (IL-6), and hs-CRP, compared with the median group, but the association was not significant. An insufficient 25(OH)D concentration (<14.22 ng/mL) was significantly related to the risk of elevated waist circumference (WC) (OR = 1.612 (1.014–2.561)) and TG (OR = 2.210 (1.318–3.706)), and reduced HDL-C (OR = 1.639 (1.206–2.229)) after adjusting for the confounders among these women. Moreover, these relationships were not affected by vitamin D metabolism-related gene polymorphisms. Conclusion: After comprehensively considering various influencing factors, significant associations between insufficient serum 25(OH)D and MetS‘s components, including elevated WC, TG, and reduced HDL-C, were observed. However, MetS, hypertension, and hyperglycemia were not found independently associated with 25(OH)D levels.

OBJECTIVE:To analyze the relationship between vitamin D(VitD)-related single nucleotide polymorphism(SNP) and 25-hydroxyvitamin D(25(OH) D) levels and VitD nutritional status.METHODS:A total of 1507 women of childbearing age aged 18-45 were selected from the sample bank of "2015 Chinese adult chronic disease and nutrition monitoring". Basic information(including region, season, age, height, weight, etc. ) of the subjects was collected. The SNPs related to VitD metabolism were screened, and the improved multiple ligase detection reaction was used for SNP testing. Liquid chromatography tandem mass spectrometry was used to determine the serum 25(OH)D concentration. The effects of genotypes on 25(OH)D level and VitD deficiency were analyzed by generalized linear model and binary logistic regression model, respectively.RESULTS:After adjusting for latitude, region, region type, season and age, CYP2R1 rs12794714, GC rs2282679, GC rs7041 and VDR rs2228570 were associated with serum 25(OH)D levels in women of childbearing age. The risk of VitD deficiency in individuals carrying GG genotype at rs2282679 was significantly higher than that in individuals carrying TT genotype(OR=2.466, 95%CI 1.690-3.598, P&lt;0.001), and the risk of VitD deficiency in individuals carrying A allele at rs2228570 was lower than that in individuals carrying G allele(OR_(AA)=0.625, 95%CI 0.446-0.876, P_(AA)=0.006;OR_(GA)=0.661, 95%CI 0.502-0.869, P_(GA)=0.003).CONCLUSION:The genotype distribution of CYP2R1 rs12794714, GC rs2282679, GC rs7041 and VDR rs2228570 may be related to serum 25(OH)D level or VitD nutritional status of Chinese women of childbearing age.

OBJECTIVETo investigate the association of rs7041 polymorphism of GC gene that encodes the vitamin D-binding protein with serum vitamin D status in Chinese women of childbearing age.METHODSA total of 1812 plasma samples of women childbearing aged 18-44 years old were selected by stratified random sampling technology from the established biological samples bank of Chinese Chronic Diseases and Nutrition Survey(CCDNS, 2015-2018). The serum 25(OH)D status was detected by enzyme-linked immunosorbent assay. The genotypes of rs7041 in the GC gene were analyzed by improved multiple ligase detection reaction method.RESULTSA total of 1812 childbearing women aged 18-49 years were included in this study. The frequency of rs7041 genotypes in the study were distributed according to the Hardy-Weinberg equilibrium, indicating sufficient representativeness of our sample. The median serum 25(OH)D status was 16. 69(12. 04, 21. 69)ng/mL. The higher 25(OH)D levels was detected in the overall sample, southern women or women with normal vitamin D status with the CC genotype than the AA genotype(P<0. 05). Before and after correction, the risk of vitamin D insufficiency in the women carrying the CC genotype was decreased significantly compared with the women carrying the AA genotype(OR=0. 571, 95%CI 0. 373-0. 873). And the CC genotype of rs7041 was associated with a significant decrease in risk of 25(OH)D deficiency(in the subgroup of southern childbearing women, OR=0. 284, 95%CI 0. 144-0. 560 and in the subgroup of northern childbearing women, OR=0. 109, 95%CI 0. 015-0. 798).CONCLUSIONThe GC rs7041 with A/C polymorphism are significantly correlated with 25(OH)D status in Chinese childbearing women, mutant CC genotype is a protective factor for vitamin D non-normal status risks.

维生素D是人体必需物质,参与机体骨骼代谢等多种生理过程.维生素D缺乏已成为世界性营养问题,这使得人们关注影响维生素D水平的高危因素.除了环境因素(包括膳食补充、紫外线暴露等)外,遗传因素的作用也日益受到重视.参与维生素D代谢调控的主要基因有10个:VDR/DBP/CYP/NADSYN1/DHCR7/AMDHD1/SEC23 A/CUBN/LRP2/RXRA.本文就近5年国内外这些基因多态性与维生素D代谢关系的进展进行综述.