Vitamin D Deficiency Still Growing
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.
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.
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