Assessment of selenium nutritional status of school-age children from rural areas of China in 2002 and 2012

Systematic Literature Review of the Nutrient Status, Intake, and Diet Quality of Chinese Children across Different Age Groups

There is a lack of comprehensive reports on nutrient deficiencies and dietary intake among various age groups of children in China. The objective of this review is to provide an overview of the nutrient status, intake, and diet adequacy of Chinese children (0-18 years old). PubMed and Scopus were searched for literature published between January 2010 and July 2022. A systematic review approach with a quality assessment was performed to analyze 2986 identified articles in English and Chinese. Eighty-three articles were included in the analysis. In younger children, anemia and iron and Vitamin A deficiencies remain severe public health problems, despite high Vitamin A and adequate iron intake. In older children, a high prevalence of selenium; Vitamin A and D deficiencies; and inadequate intakes of Vitamins A, D, B, C, selenium, and calcium were reported. Intakes of dairy, soybeans, fruits, and vegetables were below recommended levels. High intakes of iodine, total and saturated fat, and sodium and low dietary diversity scores were also reported. As nutritional concerns vary with age and region, future nutrition interventions should be tailored accordingly.

Ribosomal DNA copy number associated with blood metal levels in school-age children: A follow-up study on a municipal waste incinerator in Zhejiang, China

To evaluate the body burdens of heavy metals and explore the impact of environmental metal exposure on ribosomal DNA (rDNA) or mitochondrial DNA (mtDNA) copy number (CN) variation in school-age children living near a municipal waste incinerator (MWI), we conducted a follow-up study in 2019. A total of 146 sixth-grade children from a primary school located 1.2 km away from the MWI were recruited for our study. Metals, including vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), stannum (Sn), stibium (Sb), thallium (Tl), and lead (Pb), were determined by an inductively coupled plasma mass spectrometer method. Real-time qPCR was used to measure the rDNA and mtDNA CN. The blood metal levels followed this order: Zn > Cu > Se > Pb > Mn > Sb > As > Ni > Cd > Co > Cr > Sn > V > Tl. Blood Cr level was significantly correlated with 18 S, 2.5 S, and 45 S CN (β = -0.25, -0.22, -0.26, p < 0.05); Ni was correlated with 5 S (β = -0.36, p < 0.01); Cu was correlated with 28 S, 18 S, and 5.8 S (β = -0.24, -0.24, -0.23, p < 0.05); while Zn was correlated with 18 S, 5.8 S, and 45 S (β = -0.28, -0.32, -0.26, p < 0.05). In conclusion, school-age children living near the MWI had lower blood metal levels compared to children recruited in 2013, while rDNA CN loss was found to be correlated to several heavy metals in these children.

Analysis of Intracellular and Extracellular Selenium Concentrations: Differences According to Training Level

Trace mineral element concentrations are under homeostatic control. Selenium (Se) is a very important micronutrient for the antioxidant and immune system. Se metabolism could be modified due to physical training. This research aimed to analyze the extracellular (plasma, urine and serum) and intracellular (platelets and erythrocytes) concentrations of Se in athletes and to compare it with subjects with low levels of physical training. Forty young men divided into a control group (CG; n = 20; 19.25 ± 0.39 years) and a training group (TG; n = 20; 18.15 ± 0.27 years) participated in this study. The TG was formed by semi-professional soccer players. The analysis of Se was determined by inductively coupled plasma mass spectrometry. The TG obtained higher values of maximum oxygen consumption and muscle percentage (p < 0.05). The TG showed reduced absolute (p < 0.01) and relative (p < 0.05) Se concentrations in erythrocytes and platelets in comparison to CG. Trace element assessments should not be limited only to extracellular compartments as there could be deficiencies at the intracellular level.

Calculation of an Adequate Intake (AI) Value and Safe Range of Selenium (Se) for Chinese Infants 0-3 Months Old Based on Se Concentration in the Milk of Lactating Chinese Women with Optimal Se Intake

The required selenium intake for optimal health in Chinese residents was published in 2014. However, the adequate intake (AI) value for Chinese infants 0-3 months old is not established. This study assessed the current selenium nutritional status of 264 lactating Chinese women from three geographical locations with different Se levels (Liangshan in Sichuan province, Enshi in Hubei province, and Xicheng District in Beijing), to screen mothers with optimal Se intake, and to modify the AI value of Se for Chinese infants 0-3 months old. Milk and plasma Se concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS) and glutathione peroxidase 3 (GPx3), and plasma selenoprotein P (SEPP1) was measured by ELISA. Daily Se intake (Y, μg/day) in lactating Chinese woman was calculated from plasma Se concentrations (X, μg/L) using the formula logY = 1.623 log(X) + 3.433. Plasma Se concentrations in lactating Chinese women were 78.19 ± 25.71, 112.48 ± 24.57, and 183.83 ± 45.81 μg/L from Se-deficient, Se-moderate, and seleniferous areas, respectively. Se intakes calculated from concentrations of plasma Se were 45.6 ± 21.69, 80.03 ± 27.69, and 223.10 ± 50.95 μg/day, respectively. An optimal dietary Se intake is not lower than the recommended nutrient intake (RNI) but not more than the tolerable upper intake level (UL). A range of 78-400 μg Se/day was defined as the optimal daily Se intake for lactating Chinese women. The percentages of mothers within this range in Sichuan, Beijing, and Enshi were 8.11, 45.13, and 6.06%, respectively. Based on milk Se concentrations of mothers with optimal daily Se intake, the adequate Se intake value and a safe range for Chinese infants 0-3 months of age were calculated as 15.29 and 8-35 μg Se/day, respectively. The Se status of Chinese lactating women has improved, particularly in traditionally Se-deficient and Se-toxic regions. A safe range for daily Se intake in Chinese infants may be regarded as a guideline for infant formula.