Objective: To determine the basal metabolic rate (BMR) of young adults aged between 20-29 years old in Changsha. Methods: We recruited volunteers to join in our research project from April to May, 2015. All recruited volunteers must meet the inclusion criteria: aged 20-29 years old, height between 164-180 centimeters in males and 154-167 centimeters in females, in good health condition, and with no habit of regular physical exercise in last year. Finally, 81 qualified volunteers were selected as research objects, including 43 males and 38 females. The BMR, resting lying metabolism rate and resting sitting metabolism rate of the subjects were detected, and the determined BMR was compared with the calculated results: from the adjusted Schofield equation. Results The BMR, resting lying metabolism rate and resting sitting metabolism rate among males were (166.10±22.09), (174.22±24.56), and (179.54±23.35) kJ·m^-2·h^-1, respectively, which were all higher than those among females were (137.70±20.04), (149.79±19.25), and (167.78±26.02) kJ·m^-2·h^-1, respectively, (P<0.001). The BMR of males and females calculated from the adjusted Schofield equation were (160.83±3.93), and (140.29±4.18) kJ·m^-2·h^-1, respectively, and there was no significantly statistical difference found between the determined BMR and the calculated results from Schofield equation (adjusted) classified by sex, all P values >0.05. Conclusion The BMR of young adults aged 20-29 years old in Changsha was in the national average level, and the adjusted Schofield equation displayed fine accuracy in predicting BMR of young adults aged 20-29 years old in Changsha.

Objective: To investigate the vitamin A nutritional status of 6- to 17-year-old urban children and adolescents by analyzing serum retinol level, between 2010 and 2012 in China. Methods: Data were obtained from the China Nutrition and Health Survey in 2010-2012. Using multi-stage stratified sampling and the population proportional stratified random sampling method, 6 617 children aged 6-17 years from 32 metropolis and 41 middle-sized and small cities of China were selected. The questionnaire survey was used to collect demographic information. Blood samples were analyzed using high-performance liquid chromatography to determine serum retinol concentration, and the World Health Organization guidelines were used to evaluate the nutritional status of vitamin A. Vitamin A levels, vitamin A deficiency, and marginal vitamin A deficiency in children with different characteristics were compared. Results: A total of 3 785 cases with valid samples were obtained. The overall mean serum retinol concentration level was (1.49±0.71) μmol/L; the mean serum retinol concentration was (1.55±0.69) μmol/L for metropolis and (1.49±0.75) μmol/L for middle-sized and small cities (P>0.05). The mean serum retinol concentration was (1.52±0.78) μmol/L for boys and (1.47±0.68) μmol/L for girls (P>0.05). The mean serum retinol concentration level was (1.46±0.70) μmol/L for 6- to 11-year-old children and (1.54±0.65) μmol/L for 12- to 17-year-old children (P<0.05). The total vitamin A deficiency rate and marginal vitamin A deficiency rate was 7.69% (291/3 785) and 18.57% (703/3 785), respectively. The vitamin A deficiency rate was 8.00% (36/450) for metropolis and 7.64% (65/3 335) for middle-sized and small cities; 8.12% (155/1 908) for boys and 7.25% (136/1 877) for girls; and 8.04% (171/2 115) for 6- to 11-year-old children and 7.18% (120/1 670) for 12- to 17-year-old children. No significant differences were observed for region, sex, or age (P>0.05). The marginal vitamin A deficiency rate was 19.11% (86/450) for metropolis and 18.50% (617/3 335) for middle-sized and small cities; 18.19% (347/1 908) for boys and 18.97% (356/1 877) for girls, with no significant differences observed (P>0.05). The marginal vitamin A deficiency rate was 16.54% (350/2 115) for 6- to 11-year-old children and 21.13% (353/1 670) for 12- to 17-year-old children (P<0.05). Conclusion The vitamin A nutritional status of 6- to 17-year-old Chinese urban children and adolescents between 2010 and 2012 has improved, and the gap between cities is narrowing. However, vitamin A deficiency overall remains high, especially in younger children, and requires specific attention.

Objective: To evaluate the vitamin D nutritional status in Chinese women of child-bearing age by analyzing serum 25-hydroxyvitamin D level in 2010-2012. Methods: Data were obtained from the China Nutrition and Health Survey in 2010-2012. Using cluster sampling and proportional stratified random sampling, 1 514 women of child-bearing age (18-44 years old) from 34 metropolis and 41 small and medium-sized cities were included in this study. Demographic information was collected by questionnaire and serum 25-hydroxyvitamin D concentration was determined by radioimmunoassay, in accordance with the 2010 Institute of Medicine of the National Academies standards. We compared differences in vitamin D levels, specifically serious deficiency, lack of deficiency, insufficiency, and excess. Results: The overall serum 25-hydroxyvitamin D level of Chinese urban women of child-bearing age (P₅₀ (P₂₅-P₇₅)) was 20.1 (15.1-26.3) ng/ml; minorities had a significantly higher serum 25-hydroxyvitamin D level of 22.0 (15.9-27.5) ng/ml compared with women of Han nationality (19.8 (14.9-26.2) ng/ml) (χ²=7.02, P=0.008). The proportions of women with serious deficiency, lack of deficiency, insufficiency, and excess vitamin D were 11.6% (n=175), 37.9% (n=574), 35.1% (n=531), and 0.3% (n=5), respectively. Only 15.1% (n=229) of women of child-bearing age had normal vitamin D nutritional status. No significant differences in vitamin D nutritional status were observed according to age, body mass index, city, nationality, educational level, marital status, or household income per capita (P>0.05). Conclusion Most Chinese urban women of child-bearing age have poor vitamin D levels and require vitamin D supplementation.

Objective: To assess the vitamin A nutritional status of the Chinese urban elderly population by analyzing serum retinol level in 2010-2012. Methods: Data were collected from the Chinese National Nutrition and Health Survey in 2010-2012. Using the multi-stage stratified cluster sampling method, serum samples from elderly residents aged ≥60 years old were obtained from 34 metropolis and 41 middle-sized and small cities. Demographic data were collected using a questionnaire survey. The serum retinol concentration was determined by high-performance liquid chromatography. Vitamin A deficiency (VAD) was determined using the World Health Organization guidelines. A total of 3 200 elderly residents were included in the study. The serum retinol levels and prevalence of VAD and marginal VAD were also compared. Results: The serum retinol concentration (P₅₀(P₂₅-P₇₅)) of Chinese urban elderly residents was 1.83 (1.37-2.39) μmoL/L. Compared with middle-sized and small cities (1.91 (1.47-2.48) μmol/L), the retinol level of senior citizens in metropolis (1.70 (1.25-2.25) μmol/L) was significantly lower (P<0.001). The serum retinol levels of elderly male (1.89 (1.37-2.47) μmoL/L) was significantly higher than that of female (1.80 (1.36-2.28) μmoL/L) (P=0.001). The serum retinol concentration was 1.87 (1.42-2.43), 1.78 (1.32-2.33), and 1.71 (1.24-2.24) μmol/L for 60-69, 70-79, and ≥80 years olds, respectively. The retinol level in elderly people ≥70 years olds was significantly lower than that of 60-69 years olds (P<0.001). The overall prevalence of VAD among Chinese urban elderly residents was 4.22% (135/3 200); 6.00% (81/1 350) for metropolis residents and 2.92% (54/1 850) for middle-sized and small city residents. The overall marginal VAD rate of Chinese urban elderly residents was 8.19% (262/3 200); 10.51% (142/1 350) for metropolis residents and 6.49% (120/1 850) for medium-sized and small city residents. The prevalence of VAD and marginal VAD for males was 3.87% (61/1 577) and 8.24% (130/1 577), respectively (P<0.05). The prevalence of VAD according to age group was 3.65% (72/1 975), 4.96% (50/1 008), and 5.99% (13/217), respectively(P=0.097). The prevalence of marginal VAD according to age group was 6.99% (138/1 975), 9.82% (99/1 008), and 11.52% (25/217), respectively(P=0.05). Conclusion Chinese urban elderly residents showed various levels of VAD, although marginal VAD was quite common. As VAD was more common in metropolis residents and older residents, specific strategies should target these populations.