Vitamin D Nutritional Status and its Related Factors for Chinese Children and Adolescents in 2010–2012

Abstract

Vitamin D plays a critical role in calcium and phosphate metabolism and helps maintain skeletal integrity in childhood, yet vitamin D status in Chinese children and adolescents is not well documented. The aim of this study was to assess the vitamin D status and analyze the risk factors for vitamin D deficiency in Chinese children and adolescents aged 6–17 years. Serum 25 hydroxyvitamin D (25(OH)D) was measured with a radioimmunoassay kit in 15,000 children and adolescent participants in the Chinese national nutrition and health survey (CNNHS) 2010–2012. Age, gender, region type, ethnicity, outdoor time, and vitamin D supplementation were recorded in unified design questionnaires. The season was recorded by the date of blood taken; location was divided into north and south by China’s Qinling Mountains and Huaihe River; and ambient ultraviolet B (UVB) radiation level was classified according to the corresponding dose of each participant living area from National Aeronautics and Space Administration data. 14,473 participants from the cross-sectional study of CNNHS 2010–2012 were included in this study. The median serum 25(OH)D concentration was 48.2 (35.4–63.4) nmol/L, and the concentration for males was 50.0 (36.5–65.7) nmol/L, which was statistically higher than that of females (46.7 (34.4–60.9) nmol/L) (P < 0.001). The general prevalence of vitamin D deficiency was 53.2%; 50.0% for males and 56.5% for females at the cut-off 50 nmol/L. According to the results of the log-binomial regression analysis, vitamin D deficiency in Chinese children and adolescents was specifically related to female gender (P < 0.0001), to ages 12–14 years (P < 0.0001) and 15–17 years (P < 0.0001), living in large cities (P < 0.0001) or ordinary rural areas (P < 0.0001), low ambient UVB levels (P < 0.0001) and medium ambient UVB levels (P < 0.0001), spring (P < 0.0001), autumn (P < 0.0001) and winter seasons (P < 0.0001). The data showed that vitamin D deficiency was very common among children and adolescents aged 6–17 years in China. Effective sun exposure should be encouraged in both genders aged 6–17 years, dietary vitamin D and vitamin D supplements are also recommended, especially in the seasons of spring and winter.

Variation Trend of Vitamin D Status in Wintertime Among Infants: A Cross-sectional Study

“…Manios et al did not find the regional differences on vitamin D status during winter [11]. But in the present study, the infant living in rural region were more at risk for vitamin D deficiency than those live in urban areas, consistently with the results from Chinese children and adolescents [29]. The quality of formula and vitamin D supplements might explain these difference.…”

Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections

“…Interestingly, while the highest vitamin D levels were reported in North America, data from the United States still indicate that 8% of the non-infant population was at risk for vitamin D deficiency, and 17% exhibited concentrations below the 25(OH)D level that is associated with desirable intake [53]. Other studies based on 25(OH)D levels indicate that vitamin D inadequacy or deficiency are also prevalent in Europe and China [54][55][56]. Similarly, a recent systematic review involving 132 studies of serum alpha-tocopherol status indicated that 13% of the values were below the threshold of deficiency (12 mmol/L).…”

Effects of variants of 50 genes on diabetes risk among the Chinese population born in the early 1960s

“…According to data provided by the China National Bureau of Statistics, the country was classified into four strata based on economy and social development: large cities, medium and small cities, ordinary rural areas, and poor rural areas . Subjects were recruited to the study using a stratified multistage cluster and probability proportional to size sampling design, which has been described previously . Questionnaires were used to collect information on demographic characteristics.…”

“…13 Subjects were recruited to the study using a stratified multistage cluster and probability proportional to size sampling design, which has been described previously. 14 Questionnaires were used to collect information on demographic characteristics. Blood samples were collected from subjects.…”