Update on vitamin D status in sunshine-abundant Thailand, 2019–2020

Abstract

ObjectiveThe prevalence of vitamin D deficiency worldwide remains unknown. In the Thai 4th National Health Examination Survey (2008–2009) cohort, ∼45% and 7% of the adult population had serum 25-hydroxyvitamin-D [25(OH)D] levels below the threshold of 75 and 50 nmol/L, respectively. Vitamin D has been a hot topic in the scientific community. The aim of this study was to uncover the current situation regarding vitamin D status in Thailand. MethodsParticipants were 4098 adults ages 10 to 96 y, randomly selected from the Thai 6th National Health Examination Survey (2019–2020) cohort. Serum 25(OH)D levels were measured by liquid chromatography/tandem mass spectrometry. Data were expressed as mean ± SE and adjusted odds ratio (95% CI). ResultsMean vitamin D status based on serum 25(OH)D was 88.2 nmol/L and differed by age, sex, residency, and religion. The prevalence of serum 25(OH)D <75 and <50 nmol/L were 31% and 4%, respectively. The prevalence of vitamin D deficiency was lower in individuals who lived in the northeastern part of Thailand or were male. The risk for vitamin D deficiency was lower than that in 2009. In multiple linear regression analysis, female sex, younger age, urbanization, a higher body mass index, Muslim religion, and living in Bangkok or the central region of Thailand were independently associated with lower serum 25(OH)D levels. ConclusionsThe vitamin D status in the Thai population has improved over the past 10 y. This improvement may reflect an increased awareness related to adequate vitamin D status.