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ClinicalTrials.gov Identifier: NCT03221972
Recruitment Status :
First Posted : July 19, 2017
Last Update Posted : July 19, 2017
Information provided by (Responsible Party):
Lichen Yang, Centers for Disease Control and Prevention, China
The aim of this study was to assess the vitamin D status and analyze risk factors for vitamin D inadequacy of Chinese children and adolescents aged 6-17y.
Condition or disease
Vitamin D Deficiency
In this study, we analyzed the vitamin D status of Chinese children and adolescents aged 6-17y, and related risk factors (such as gender, region strata, ambient UVB level at area of residence, season, and outdoor time, etc.). Serum 25 hydroxyvitamin D [25(OH)D] was measured with a radioimmunoassay kit in 15 000 children and adolescent participants in Chinese national nutrition and health survey (CNNHS) 2010-2012. Age, gender, region type, ethnicity, outdoor time, vitamin D supplementation were recorded in unified design questionnaires. 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.
25 hydroxyvitamin D [ Time Frame: through study completion, an average of 1 year ]
To describe the vitamin D status,ng/mL.
Secondary Outcome Measures :
Demographic data [ Time Frame: through study completion, an average of 1 year ]
age, gender, ethnicity
Environmental data [ Time Frame: up to 25 weeks ]
season,region type, latitude, ambient ultraviolet B radiation level
Outdoor time [ Time Frame: through study completion, an average of 1 year ]
outdoor activity time
Vitamin D supplementation [ Time Frame: through study completion, an average of 1 year ]
frequency of vitamin D supplements taking for each participant
Biospecimen Retention: Samples Without DNA
2 mL of fasting venous blood was collected and centrifuged at 1500×g for 15 minutes within 30 minutes after blood taken. The upper serum was aliquoted and stored in brown vessel at -20℃ in the laboratory where the investigation point was located. All the serum specimens from all the 150 investigation points were transported to our laboratory by cold chain. All the samples were preserved at -70℃ refrigerator before determination.
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Layout table for eligibility information
Ages Eligible for Study:
6 Years to 17 Years (Child)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
The participants of this study were aged 6-17y selected from the Chinese national nutrition and health survey
Participanted in China national nutrition and health survey (CNNHS) 2010-2012; Aged 6-17 years; Had blood taken;