Reevaluation of the protein requirement in Chinese elderly adults without sarcopenia with the indicator amino acid oxidation technique.

It is now generally believed that elderly may have slightly higher dietary protein requirements than those of the young-middle-aged adults. We have previously conducted related studies by the indicator amino acid oxidation (IAAO) technique, but more research data are needed to revise the protein requirements of the elderly. The main objective was to reevaluate the dietary protein requirements of healthy Chinese adults (65-80 years) without sarcopenia by using the IAAO technique. Nine healthy adult men and seven healthy adult women participated in the study, with protein intakes ranging from 0·1 to 1·8 g/(kg·d). Diets that delivered energy at a 1·5 resting energy expenditure were isocaloric. The amounts of phenylalanine and tyrosine needed to remain constant for each protein dosage. By applying a nonlinear mixed-effects model analysis on the F13CO2 data, which revealed a breakpoint in F13CO2 in response to graded protein intakes, the mean protein requirement was calculated. The mean estimated average requirement (EAR) for healthy elderly Chinese adults without sarcopenia was determined to be 0·94 g/(kg·d). The protein recommended nutrient intake (RNI) determined using various derivation approaches ranged from 1·13 to 1·36 g/(kg·d). The EAR for Chinese adults without sarcopenia aged 65-80 years in this study is 6·8 % higher than the current recommended EAR (0·88 g/(kg·d)). The RNI derived using various derivation approaches are all greater than the current RNI (0·98 g/(kg·d)). This trial was registered with the Chinese clinical trial registry as ChiCTR2200061382.

[Blood cadmium level and the change of cadmium exposure risk in Chinese urban school-age children in 2002 and 2012].

OBJECTIVE: To investigate the blood cadmium concentrations and the related change in Chinese urban children derived from the China Nutrition and Health Survey 2002 and 2012(CNHS 2002 and CNHS 2012). METHODS: The Chinese urban children aged 6-11 years were selected according to gender, age and regional distribution using the multi-stage stratified cluster random sampling method, as well as the corresponding whole blood samples. The blood cadmium concentration was carefully determined by the quadrupole inductively coupled plasma mass spectrometry(ICP-MS) and the percentage of blood cadmium over 2 µg/L was subsequently estimated. In addition, the upper limit values of the 95%CI of the 95th percentiles of available blood cadmium data was assessed as the threshold of cadmium exposure. RESULTS: Totally, 2182 Chinese urban children were included, and of these, 1036 children were from the CNHS 2002 and 1146 children were from the CNHS 2012. From the CNHS 2002 to the CNHS 2012, the median blood cadmium concentration was increased from 0.28 µg/L to 0.95 µg/L, and the percentage of blood cadmium with over 2 µg/L was elevated from 1.45% to 10.47%. In addition, the new estimated threshold of blood cadmium was ascended from 1.24 µg/L up to 2.89 µg/L. CONCLUSION: The risk of cadmium exposure in Chinese urban children aged 6-11 years was increasingly aggravated from the CHNS 2002 to the CNHS 2012.

Re-exploration of dietary iodine intake in Chinese adult males using a modified iodine balance study.

There is still controversy about optimal dietary iodine intake as the Universal Salt Iodization policy enforcement in China. A modified iodine balance study was thus conducted to explore the suitable iodine intake in Chinese adult males using the iodine overflow hypothesis. In this study, thirty-eight apparently healthy males (19·1 (sd 0·6) years) were recruited and provided with designed diets. After the 14-d iodine depletion, daily iodine intake gradually increased in the 30-d iodine supplementation, consisting of six stages and each of 5 d. All foods and excreta (urine, faeces) were collected to examine daily iodine intake, iodine excretion and the changes of iodine increment in relation to those values at stage 1. The dose-response associations of iodine intake increment with excretion increment were fitted by the mixed effects models, as well as with retention increment. Daily iodine intake and excretion were 16·3 and 54·3 µg/d at stage 1, and iodine intake increment increased from 11·2 µg/d at stage 2 to 118·0 µg/d at stage 6, while excretion increment elevated from 21·5 to 95·0 µg/d. A zero iodine balance was dynamically achieved as 48·0 µg/d of iodine intake. The estimated average requirement and recommended nutrient intake were severally 48·0 and 67·2 µg/d, which could be corresponded to a daily iodine intake of 0·74 and 1·04 µg/kg per d. The results of our study indicate that roughly half of current iodine intakes recommendation could be enough in Chinese adult males, which would be beneficial for the revision of dietary reference intakes.

[Relationship between vitamin D and parathyroid hormone in Chinese elderly people].

OBJECTIVE: To explore the relationship between serum 25-hydroxyvitamin D(25(OH)D) and serum parathyroid hormone(PTH) level in Chinese people aged 50 years and above, and to probe the optimum threshold for vitamin D sufficiency preliminarily, and apply this threshold to predict the risk of metabolic syndrome(Mets) in this population. METHODS: A total of 750 serum samples were selected from the biological samples' bank of Chinese Chronic Diseases and Nutritional Survey(CCDNS, 2015-2017) by stratified sampling, basic information(including age, gender, season, etc. ) were collected from questionnaire and physical measurement of the subjects were conducted unified. Serum 25(OH)D concentration was determined by high performance liquid chromatography tandem mass spectrometer, and PTH and interleukin-6(IL-6) were detected by electrochemiluminescence method. Phosphorus, albumin(Alb), creatinine(Cr) in blood were detected by automatic biochemical analyzer. Factors affecting the concentration of 25(OH)D and PTH were found by multiple linear regression and adjusted by generalized additive model separately, threshold was predicted by locally weighted regression and smoothing scatterplot, abbreviated as LOESS, and the exact threshold of 25(OH)D was found when PTH reached the plateau by nonlinear least squares estimation and segmented regression. Relationship between 25(OH)D and Mets was analyzed by multivariate logistic regression using the different cut-off points in Chinese elderly people. RESULTS: Reference threshold for vitamin D deficiency in Chinese elderly people can be preliminarily discovered as serum total 25(OH)D was 19.62 ng/mL, and 28.44 ng/mL can be used as reference threshold for sufficient vitamin D. Sufficient 25(OH)D(≥28.44 ng/mL) could reduce the risk of Mets significantly(OR=0.617(0.439-0.869)) after adjusting for confounding factors such as sex, age, region, season, ect. A plateau in PTH was observed at a 25(OH)D concentration of 20.03-28.43 ng/mL for male whereas 13.12-26.33 ng/mL for female by gender stratification analysis, but no cut-off point was obtained statistically. CONCLUSION: Reference threshold for vitamin D sufficiency in Chinese elderly people was preliminarily observed in the range of 19.62-28.44 ng/mL when PTH was maximally inhibited, and the threshold may vary with gender. Applying the threshold we also found that more sufficient levels of vitamin D were protective against Mets in this population.

[Plasma selenium level and its influencing factors in Chinese child-bearing-aged women in 2015].

OBJECTIVE: To assess the plasma selenium(Se) level of child-bearing-aged women and discuss the influence factor for low-Se level. METHODS: Using the muti-stage stratified and population proportional cluster random sampling method, 1881 child-bearing-aged women aged 18 to 44 years were selected from China Adult Chronic Disease and Nutrition Surveillance(2015) Data. The basic information of the subjects was collected by unified electronic questionnaires and equipments were used for field survey, measurement and record. Plasma Se concentration was detected by inductively coupled plasma mass spectrometry. Plasma low-Se level were assessed using lower limit of plasma/serum Se established by the Mayo Clinic Laboratory and our laboratory, respectively. Influence factors of low-Se level were analyzed by the multivariate logistic regression model. RESULTS: The M(P25, P75) plasma Se concentration for Chinese child-bearing-aged women was 89.52(74.21, 105.03)µg/L. Nationality, location, urban-rural type and education level difference had influence on plasma Se level in this population(P<0.05). According to the lower limit of plasma/serum Se concentration established by the Mayo clinical laboratories(<70 µg/L) and our laboratories(<73.81 µg/L), the low-Se rate were 20.47% and 24.51%, respectively. There were significantly differences in low-Se rate among nationality, location, urban-rural type, education level and marital status(P<0.05). The multivariate logistic regression model showed that location and urban-rural type had significant effects on low-Se rate of child-bearing-aged women(P<0.05). CONCLUSION: The plasma low-Se rate of Chinese women of childbearing age is relatively high and higher prevalence low-Se was found in western and central regions and rural areas in China.

[Protein efficiency ratio of genetically modified pork powder with fat-1 gene].

OBJECTIVE: To evaluate the protein efficiency ratio(PER) of genetically modified pork powder with fat-1 gene(GM group), and thus evaluate whether the nutritional evaluation value of fat-1 gene pork powder has changed. METHODS: Sixty weaned SD rats(60-80 g) were randomly divided into casein group, parental control group and GM group according to sex and weight, 20 rats in each group, half of each sex. The rats in the three groups were fed with corresponding formulated feed containing 10% protein for 28 days. The body weight and food intake of each group were recorded weekly. Blood was collected at the end of the experiment to determine hematology and blood biochemical indexes. The food utilization rate, organ/body weigh indexes, PER and corrected PER were calculated. RESULTS: The weight of rats in all groups increased steadily during the experimental period. Statistically significant differences were found in some hematology and blood biochemical indexes and organ/body weigh indexes. No biologically significant changes were found. The food utilization rate of GM group was higher than that of casein group(P<0.05), which was equivalent to that in the parental control group. The PER of both genetically modified pork powder with fat-1 gene and parental white pork powder were higher than that of casein(P<0.05). CONCLUSION: The PER of genetically modified pork powder with fat-1 gene was equal to that of its parental white pork powder.

Exploration of the lower threshold of iodine intake in Southern Chinese young adults based on 'overflow theory' in an iodine balance study.

BACKGROUND: Appropriate iodine intake for adults is essential to reduce the prevalence of thyroid diseases, but there is little research data on iodine requirement of Chinese population. This study aimed to explore the iodine requirement of young adults to maintain a healthy status based on 'overflow theory'. METHODS: Iodine-balance experiment has been performed in this project. We conducted an 18-day study consisted of a 6-day acclimation period and 3 consecutive experimental stages in 37 Chinese healthy young adults (23 female and 14 male). Each stage was consumed for 4 days. Strictly-controlled low-iodine intake diets were provided for adults in the first period, an egg or 125mL milk was added in the second and third period, respectively. The dietary samples, 24-h urine specimens and faeces of volunteers were collected daily for assessment of iodine intake and excretion in volunteers. RESULTS: Mean values of iodine intake (22.7±3.6, 35.1±3.7, and 52.2±3.8µg/d), excretion (64.7±13.9, 62.3±12.6, and 94.3±14.5µg/d) and iodine balance (-35.2±19.5, -21.0±19.8, and -33.5±26.9µg/d) were significantly different among three periods for male (P<0.001 for all); mean values of iodine intake (16.6±3.1, 29.7±2.7, and 48.0±2.7µg/d), and excretion (47.0±9.9, 55.5±8.1, and 75.7±12.4µg/d) were significantly different among three periods for female (P < 0.001 for all). No significant difference was observed among the 3 periods for female in the iodine balance (-30.5±9.3, -25.9±7.3, and -27.6±12.1µg/d). The linear regression equation of iodine excretion on iodine intake was Y=0.979X+37.04 (male) and Y=0.895X+31.48 (female). Compared with stage 2, iodine excretion increments in stage 3 had exceeded the iodine intake increment for men. The ratio of increment was 1.675 for male when the average iodine intake was 52.2µg/d in stage 3. When the iodine excretion increment equaled to the iodine intake increment, the daily iodine intake of men was 47.0µg. CONCLUSION: We have evaluated the iodine requirement of young adults in southern China based on overflow theory. Our results indicate the lower limit of iodine requirement for Chinese young men is 47.0µg/d. The trial was registered at www.chictr.org.cn as ChiCTR1800014877.

Knowledge of Oral Cancer Amongst Dental Patients Attending Public Clinics in South East Queensland, Australia.

Patient knowledge of risk factors, signs and symptoms associated with oral cancers is crucial for increasing the likelihood of patient presentation for opportunistic screening and reducing delay in patient appraisal for early detection. This study aimed to assess the knowledge of oral cancer and to ascertain socio-demographic factors that influence knowledge amongst adult dental patients attending public clinics in Brisbane, Australia. A convenience sample of 213 adult dental patients who attended the Herston and Stafford public health clinics in Brisbane, Australia, between July and August 2019 participated in the self-administered questionnaire. Multivariate analyses were performed to identify predictors for oral cancer knowledge. Patients were well informed of smoking as a risk factor (n = 135; 84.4%), whereas only 53.8% (n = 82) of participants agreed that heavy alcohol consumption was a risk factor. A larger proportion of participants identified difficulty of moving the tongue (n = 79; 49.4%) and pain on swallowing (n = 72; 45.0%) compared to the proportion who identified fixed red patches (n = 61; 38.1%) and fixed white patches (n = 57; 35.6%) as a sign or symptom. Education level and gender were significant knowledge predictors for alcohol (p = 0.01), old age (p = 0.008) and family history (p = 0.004) as a risk factors for oral cancer. Those with a family history of cancer were more likely to identify a red patch (p = 0.02), bleeding gums (p = 0.001) and altered sensation (p = 0.023) as a sign or symptom of oral cancer. Overall, patient knowledge was greater for risk factors than for signs and symptoms for oral cancer. Symptoms associated with later stages of cancer were recognised by a greater proportion of patients compared to early stages of oral cancer. These results indicate the need for targeted public health initiatives to improve patient knowledge.

[Association of vitamin D gene polymorphisms and serum 25-hydroxyvitamin D in Chinese women of childbearing age].

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<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.

[Vitamin A nutrition status of Chinese urban adults aged 18 to 60 years old in 2015].

OBJECTIVE: To investigate the vitamin A nutritional status and its related influencing factors of Chinese 18-60 urban adults by analyzing serum retinol level in 2015. METHODS: Serum samples of 42 people, half male and half female, were randomly selected in each point, from the 302 monitoring sites of Chinese adult chronic diseases and nutrition surveillance in 2015. The serum retinol levels were determined by high pressure liquid chromatography(HPLC). RESULTS: A total of 2571 serum samples were detected. The serum retinol level of Chinese urban adults of 18-60 years old was 1.98(1.56-2.53)µmol/L, the deficiency rate was 0.25%, and the marginal deficiency rate was 4.45%. The serum retinol level of male was 2.19(1.75-2.78)µmol/L, the deficiency rate was 0.05%, and the marginal deficiency rate was 2.48%; The serum retinol level of female was 1.80(1.42-2.25)µmol/L, the deficiency rate was 0.46%, and the marginal deficiency rate was 6.51%. The significant differences in serum retinol was observed deficiency rate and marginal deficiency rate between males and females(P<0.01), the nutritional status of males was better than the females. The deficiency rate and marginal deficiency rate of 18-29 years old were the highest, which were 0.34% and 5.81% respectively. The deficiency rate and marginal deficiency rate of over 50 years old were the lowest, which were 0.15% and 2.60% respectively. The vitamin A deficiency rate and marginal deficiency rate of people with body mass index(BMI)<18.5 were 0.95% and 7.24%, 0.33% and 5.85% for BMI=18.5-23.9, 0.13% and 3.27% for BMI=24.0-27.9, respectively. The differences of vitamin A deficiency rate and marginal deficiency rate among different BMI were significant. CONCLUSION: The vitamin A nutritional status of urban adults in China is good, the vitamin A deficiency rate is very low, and the incidence of vitamin A deficiency is also low. It is basically not a public health problem according the WHO standard.

[Protein efficiency ratio of genetically modified corn with Cry1Ab-ma gene].

OBJECTIVE: To evaluate the protein efficiency ratio(PER) of genetically modified corn with Cry1Ab-Ma gene and parental corn. METHODS: Sixty SD rats(60-80 g) were randomly divided into genetically modified corn group, parental corn group and casein control group, with 20 rats in each group and half male and half female. Casein was added to 10% of the diet in casein control group. When the protein content of the diets in the genetically modified corn group and parental corn group was still less than 10% according to the principle of maximum incorporation, the defective part was supplemented with casein. Rats were free to drink and eat for 28 days. Food intake and body weight of each group were recorded every week. Blood was collected at the end of the experiment to determine hematology and blood biochemical indexes. The main organs were weighed and organ/body weigh indexes were calculated. PER and corrected PER were calculated. RESULTS: The body weight of all the animals in each group showed an increasing trend, and the weight growth was normal. Although there were statistical differences in the individual indexes of end-stage hematology and blood biochemical indexes, there was no biological significance. There were no significant change in the organ/body weigh indexes. PER of genetically modified corn, parental corn and casein were 2.01±0.22, 1.77±0.30 and 3.64±0.48, respectively. The corrected PER of genetically modified corn and parent corn were 1.38 and 1.22, respectively. CONCLUSION: The PER of this batch of genetically modified corn with Cry1Ab-ma gene was better than that of parental corn, but worse than that of casein.

[Establishment and application of high performance liquid chromatography-inductively coupled plasma mass spectrometry method for the determination of iodine species in serum].

OBJECTIVE: To establish a method for the determination of iodine species in human serum by inductively coupled plasma mass spectrometry(ICP-MS). METHODS: Total iodine was determined by ICP-MS in helium mode after dilution of serum with tetramethylammonium hydroxide solution. The serum was added to methanol solution to precipitate the protein, and the supernatant was separated by liquid chromatography(LC) followed by ICP-MS for the determination of inorganic iodine. RESULTS: The limit of detection(LOD) of serum I~- by ICP-MS was 0.17 µg/L, the limit of quantification(LOQ) was 0.57 µg/L, and the linear correlation coefficient R~2=0.9998; the LOD of serum IO_3~- was 0.16 µg/L, the LOQ was 0.55 µg/L, and the linear correlation coefficient R~2=0.9998.The I~- recoveries were 96.2%-104.5% for the total serum iodine assay and 93.7%-98.6% for the inorganic iodine assay. Analysis of the iodine species of the actual serum samples showed that the I~- content was 2.6-12.2 µg/L, the organic iodine content was 45.3-66.0 µg/L, and the serum samples were essentially free of IO_3~-. CONCLUSION: A convenient, efficient and accurate method for the determination of serum iodine species was established using high performance liquid chromatography tandem with inductively coupled plasma mass spectrometry.

[Plasma proteomic analysis of diabetes improvement by vitamin D supplementation].

OBJECTIVE: To analyze the effect of vitamin D supplementation on the improvement of diabetes mellitus based on plasma proteomics. METHODS: Five-week-old SPF spontaneously obese rats with type 2 diabetes were randomly divided into a diabetic group and a diabetic vitamin D intervention group, and the control group was Zucker lean rats. The fasting blood glucose of the rats in each group was compared with that of the diabetic vitamin D group, and the plasma proteins of the rats in each group were compared by quantitative analysis of the high-resolution mass spectrometry system iTRAQ, and KEGG signaling pathway analysis was performed. RESULTS: The fasting blood glucose of rats in the diabetic vitamin D intervention group was significantly lower than that of the diabetic group, and the proteins that were differentially expressed in the diabetic vitamin D intervention group were significantly improved. KEGG signaling pathway analysis revealed that the differential proteins in the diabetic group were mainly distributed among enzymes, exosomal proteins, and peptidases and inhibitors, and that the number of differences in these three classes of proteins was significantly reduced in the diabetic intervention group. CONCLUSION: Vitamin D supplementation can improve the differential expression of fasting glucose and plasma proteins in the diabetic rats.

[Vitamin A nutrition status among pregnant women in rural China in 2015].

OBJECTIVE: To evaluate the nutrition status of vitamin A in Chinese rural pregnant women from the Chinese National Nutrition and Health Survey 2015(CNNHS 2015). METHODS: A total of 3273 Chinese rural pregnant women were recruited in this study. The concentrations of serum retinol were determined using high performance liquid chromatography. The C-reactive protein and α-acid glycoprotein were determined by immunoturbidimetric method. The distribution of serum retinol status in pregnant women was further described for different regions, age groups, nationalities, body mass index(BMI), education levels, gestational weeks, family income per capita and inflammation levels. The prevalence of vitamin A deficiency and the percentage of marginal vitamin A deficiency in pregnant women were compared in different subgroups. RESULTS: The median concentration of serum retinol(M(P25, P75)) was 0. 47(0. 36, 0. 61) mg/L. There were significant differences among different regions, age groups, education levels, gestational age and per capita household income(P<0. 01). The prevalence of vitamin A deficiency was 1. 2% for deficiency and 10. 5% for marginal deficiency, respectively. Significant differences were observed in age groups, gestational weeks and inflammation levels(P<0. 01). In addition, the prevalence of vitamin A deficiency was relatively serious, 2. 1% for deficiency and 14. 2% for marginal deficiency in the third trimester, 2. 0% for deficiency and 12. 2% for marginal in the 30-44 years. CONCLUSION: It should be pay more attention on the vitamin A nutrition status in the third trimester and the 30-44 years old pregnant women, although the vitamin A status had been greatly improved in Chinese rural pregnant women.

[Vitamin A nutrition status and influencing factors of Chinese rural elderly in 2015].

OBJECTIVE: To analyze the level of vitamin A and its influencing factors of Chinese rural elderly. METHODS: The serum samples of the rural elderly were selected by random sampling method from the biological sample bank of Chinese Adults Nutrition and Chronic Diseases Surveillance in 2015(CANCDS2015). The basic information of the subjects was collected by questionnaire survey. High performance liquid chromatography(HPLC) method was used to determine the vitamin A nutritional status of the population according to the standard recommended by WHO. Multiple logistic regression analysis was explored the relationship between vitamin A status with the potential relevant factors. RESULTS: A total of 3134 elderly from Chinese rural were included in this study. The serum vitamin A concentration(M(P25, P75))was 1. 92(1. 50, 2. 45)µmoL/L. The prevalence of vitamin A deficiency was 0. 99%(95%CI 0. 64%-1. 34%), and the prevalence of vitamin A marginal deficiency was 4. 38%(95%CI 3. 65%-5. 10%). The prevalence of vitamin A marginal deficiency was significantly higher in elderly lived in western region than that lived in eastern and central regions of China. The serum vitamin A adequacy rate of rural elderly who were 80 years old and above or thin was relatively low(P<0. 05). Married elderly had significant lower vitamin A deficiency rate. The result from multivariate logistic regression model analysis showed that gender, age and body mass index had significant effects on vitamin A nutritional status of Chinese urban elderly(P<0. 05). CONCLUSION: The nutritional status of vitamin A in rural elderly in China was better, and the deficiency rate was lower.

[Relationship between rs7041 polymorphism of GC gene and serum vitamin D status in Chinese women of childbearing age].

OBJECTIVE: To 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. METHODS: A 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. RESULTS: A 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). CONCLUSION: The 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.

[Zinc status of 18-60 year-old adults in China in 2015].

OBJECTIVE: To estimate the distribution of serum zinc levels, zinc deficiency status and possible influencing factors in 18-60 year-old adults in China. METHODS: Based on the data of China Adult Chronic Disease and Nutrition Surveillance, 3903 blood samples were selected by stratified random sampling. The distribution of serum zinc in adults with different gender, age, regional type and regional distribution were analyzed by inductively coupled plasma mass spectrometry and body mass index(BMI), exercise, smoking, drinking, vitamin A level and other factors on serum zinc concentration and zinc deficiency rate. Multivariate logistic regression model was used to analyze the correlation between zinc deficiency and the influencing factors. RESULTS: In 2015, the median of serum zinc in Chinese adults aged 18-60 years was 103. 44(95%CI 64. 84-186. 12) µg/dL, and the overall zinc deficiency rate was 6. 04%. Serum zinc concentration had statistically significant difference(P<0. 05) in different genders, regional types, regional distribution, vitamin A status, smoking status, drinking status. In the comparison of zinc deficiency rates, ethnic minorities(10. 67 %) was higher than Han(5. 44%), rural area(7. 35%) was higher than urban area(4. 90%), vitamin A deficiency group(9. 12%) was higher than vitamin A normal group(5. 90%), non-exercise group(6. 29%) was higher than sports group(5. 09%). Among different regional distributions, the western region had the highest zinc deficiency rate(7. 33%), and among different BMI groups overweight group had the lowest rate(4. 81%). These differences were statistically significant(P<0. 05). In the analysis of multivariate logistic regression, the risk of zinc deficiency in the vitamin A deficiency group was 1. 89 higher than that of the normal group(OR=1. 89, 95%CI 1. 13-3. 18); and the overweight group had a lower risk of serum zinc deficiency than the normal group(OR=0. 71, 95%CI 0. 52-0. 96). CONCLUSION: The prevalence of serum zinc deficiency among adults aged 18-60 in China is relatively low. Vitamin A deficiency is a risk factor for zinc deficiency and overweight is a protective factor for zinc deficiency.

Protein Requirements of Elderly Chinese Adults Are Higher than Current Recommendations.

BACKGROUND: Due to a lack of research data on the protein requirements of the elderly in China, the estimated average requirement (EAR) and the recommended nutrient intake (RNI) of protein in the elderly remain the same as those in young and middle-aged people at 0.98 g/(kg·d). OBJECTIVE: The objective of this study was to determine the protein requirements of healthy Chinese adults >65y old through use of the indicator amino acid oxidation (IAAO) method. METHODS: Seven healthy adult men and 7 healthy adult women participated in the study, with protein intakes ranging from 0.3 to 1.8 g/(kg·d). The diets were isocaloric and provided energy at a 1.5 resting energy expenditure. Protein was given based on the lactalbumin. Phenylalanine and tyrosine were added to protein doses of 0.3-1.5 g/kg according to the highest dose of protein content [1.8 g/(kg·d)]. Phenylalanine and tyrosine concentrations were kept constant at each protein dose. The mean protein requirement was determined by applying a nonlinear mixed-effects model analysis to the F13CO2, which identified a breakpoint in F13CO2 in response to graded amounts of protein. This trial was registered with the Chinese clinical trial registry as ChiCTR-BOC-17010930. RESULTS: Protein EAR and RNI for healthy elderly Chinese adults were determined to be 0.91 and 1.17 g/(kg·d), respectively, based on the indicator amino acid oxidation technique. CONCLUSIONS: The estimates of protein requirements for Chinese adults >65 y in the present study are 3.4% and 19.4% higher than the current estimated requirements, 0.88 g/(kg·d) for EAR and 0.98 g/(kg·d) for RNI.

An iodine balance study to explore the recommended nutrient intake of iodine in Chinese young adults.

Data on average iodine requirements for the Chinese population are limited following implementation of long-term universal salt iodisation. We explored the minimum iodine requirements of young adults in China using a balance experiment and the 'iodine overflow' hypothesis proposed by our team. Sixty healthy young adults were enrolled to consume a sequential experimental diet containing low, medium and high levels of iodine (about 20, 40 and 60 µg/d, respectively). Each dose was consumed for 4 d, and daily iodine intake, excretion and retention were assessed. All participants were in negative iodine balance throughout the study. Iodine intake, excretion and retention differed among the three iodine levels (P < 0·01 for all groups). The zero-iodine balance derived from a random effect model indicated a mean iodine intake of 102 µg/d, but poor correlation coefficients between observed and predicted iodine excretion (r 0·538 for µg/d data) and retention (r 0·304 for µg/d data). As iodine intake increased from medium to high, all of the increased iodine was excreted ('overflow') through urine and faeces by males, and 89·5 % was excreted by females. Although the high iodine level (63·4 µg/d) might be adequate in males, the corresponding level of 61·6 µg/d in females did not meet optimal requirements. Our findings indicate that a daily iodine intake of approximately half the current recommended nutrient intake (120 µg/d) may satisfy the minimum iodine requirements of young male adults in China, while a similar level is insufficient for females based on the 'iodine overflow' hypothesis.

[Exploring study on the cutoff of vitamin D deficiency in Chinese adults].

OBJECTIVE: To study the relationship between 25-hydroxyvitamin D [25(OH)D] concentration and intact parathyroid hormone(iPTH) concentration in the Chinese non-clinical population aged 18-44 y, and to explore the threshold value of determining the appropriate nutritional status of vitamin D. METHODS: A total of 650 plasma samples of adults aged 18-44 years old were selected from the established biological samples' bank of Chinese Chronic Diseases and Nutrition Survey(CCDNS, 2015-2018). Basic information(including age, gender, region type, season, etc. ) was collected by questionnaires, and the waist circumference, height and weight of the subjects were determined unified. North and South area was divided by Qinling Mountains and Huaihe River. The serum 25(OH)D concentration was determined by high performance liquid chromatography tandem mass spectrometer, and the iPTH was determined by electronic chemiluminescence method. The relationship of 25(OH)D and iPTH were analyzed by partial correlation analysis, and the threshold of 25(OH)D was analyzed by locally weighted scatter plot smoothing method after adjusting the iPTH by age, season of blood draw, BMI, waist, sex and latitude. RESULTS: A total of 623 serum samples(293 male, 330 female) of 25(OH)D concentration and iPTH concentration were analyzed after excluding samples with poor blood sample quality. Significant higher 25(OH)D concentration was found in male than female(P<0. 0001). And the samples from the southern China had higher 25(OH)D concentration than those from the northern China(P<0. 0001). Samples from autumn had higher 25(OH)D concentration than those from spring and winter(P<0. 0001). The 25(OH)D concentration of samples from cities was lower than that of rural areas(P=0. 018). The inversely relationship between 25(OH)D concentration and iPTH concentration was observed when the 25(OH)D was below 17. 6 ng/mL for both sexes. The threshold of 25(OH)D for male was 16. 2 ng/mL and it was 25. 6 ng/mL for female. CONCLUSION: The threshold and the relationship between 25(OH)D and iPTH differs by sex among Chinese adults aged 18-44 y. Further study is needed to evaluate the sex-specific ranges of optimal vitamin D.