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NCT Number: NCT03304795

Vitamin D Deficiency Still Growing

Vitamin D deficiency has become one of the most prevalent health problems in modern society. However, there has been no study that has reported the trend of vitamin D status in Asia. This study investigated the trend of vitamin D status in Korea between 2008 and 2014.

This study is based on a representative national database acquired from the Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2008 to 2014. Serum 25-hydroxyvitamin D [25(OH)D] levels were measured by radioimmunoassay among those aged 10 yrs or older. The temporal change of vitamin D status will be statistically analyzed.

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Key information

Age range

10 year and older

Sex eligibility

All sexes

Study type

Observational

About this study

Most epidemiologic studies that assessed vitamin D status in various populations have been performed in a cross-sectional design. Some studies from western countries have assessed the trends of vitamin D status over the past decades. However, there was no study that investigated the trend of vitamin D status in Asian population.

In the present study, an assessment of the seven-year trend of vitamin D status and the prevalence of vitamin D deficiency in the Korean population, based on the KNHANES conducted from 2008 to 2014 was performed.

The KNHANES is an ongoing surveillance system that has been conducted by the Division of Health and Nutrition Survey within the Korea Centers for Disease Control and Prevention to evaluate the health and nutritional status of the civilian non-institutionalized population of South Korea. Since the KNHANES was initiated in 1998, surveys for the KNHANES I (1998), KNHANES II (2001), KNHANES III (2005), KNHANES IV (2007-2009), KNHANES V (2010-2012), and KNHANES VI (2013-2015) have been executed, and the survey for KNHANES VII (2016-2018) is still in progress. The present study is based on the data acquired from the KNHANES IV-VI, conducted between 2008 and 2014. Among those participants, serum 25(OH)D levels were measured from 39,759 individuals (6,925 in 2008; 8,303 in 2009; 6,815 in 2010; 6,704 in 2011; 6,308 in 2012; 2,355 in 2013; and 2,349 in 2014) aged 10 years and older. Serum 25(OH)D concentration was categorized into 4 levels (<25, 25 to <50, 50 to <75, and ≥75 nmol/L) and the vitamin D deficiency was defined as the Serum 25 (OH) D concentration < 50 nmol/L.

Statistical analyses were conducted to evaluate the effects of participant characteristics (age, season, and residential region) on serum 25(OH)D concentrations, and the temporal change in the mean concentration of serum 25(OH)D over years 2008-2014.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participants in the KNHANES from 2008 to 2014
  • Participants who were examined for serum 25-hydroxyvitamin D level

Exclusion criteria

  • Participants without serum 25-hydroxyvitamin D level data

Treatment and study plan

Primary outcomes

  1. Vitamin D deficiency

    Time frame: 2008-2014

    Serum 25-hydroxyvitamin D level less than 50 nmol/L

Sponsors and collaborators

Lead sponsor

DongGuk University

Other

Registry information

Official study title

Is Vitamin D Deficiency Still Growing? Seven-Year Trend in KNHANES 2008-2014

Important dates

Study start
2008
Primary completion
2014
Study completion
2014
First posted
Oct 9, 2017
Registry last updated
Oct 9, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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