Assessing the effects of ultraviolet radiation, residential greenness and air pollution on vitamin D levels: A longitudinal cohort study in China.

Journal Article (Journal Article)

Vitamin D metabolism is essential in aging and can be affected by multiple environmental factors. However, most studies conducted single exposure analyses. We aim to assess the individual and combined effects of ultraviolet (UV) radiation, residential greenness, fine particulate matter (PM2.5 ), and ozone (O3 ) on vitamin D levels in a national cohort study of older adults in China. We used the 2012 and 2014 Chinese Longitudinal Healthy Longevity Survey data, and measured the environmental exposure in the same year. We interpolated the UV radiation from monitoring stations, measured residential greenness through satellite-derived Normalized Difference Vegetation Index (NDVI), modeled PM2.5 with satellite data, and estimated O3 using machine learning. We dichotomized serum 25-hydroxy vitamin D (25(OH)D), the primary circulating form of vitamin D, into non-deficiency (≥50 nmol/L) and deficiency (<50 nmol/L) categories. We used the generalized estimating equation for analysis, adjusted for sociodemographic information, lifestyle, physical condition, and season of blood draw, and calculated joint odds ratios based on the Cumulative Risk Index. We also explored the interaction between interested exposures, modification of participants' characteristics, and potential mediation. We included 1,336 participants, with a mean age of 83 at baseline. In single exposure models, the odds ratios of vitamin D deficiency (VDD) for per interquartile range increase in UV radiation, NDVI, PM2.5, and O3 and decrease were 0.39 (95 % CI:0.33,0.46), 0.90 (0.81,1.00), 1.65 (1.53,1.78), 1.67 (1.46,1.92), respectively. UV radiation mediated nearly 48 % and 78 % of the relationship between VDD and PM2.5 and O3 , respectively. The association between UV radiation and VDD was stronger in females than men (OR: 2.25 vs 1.22). UV radiation, residential greenness can protect against VDD, while, PM2.5 and O3 increase the risk of VDD. UV radiation partly mediated the association between air pollution and VDD.

Full Text

Duke Authors

Cited Authors

  • Zhang, H; Zhu, A; Liu, L; Zeng, Y; Liu, R; Ma, Z; Liu, M; Bi, J; Ji, JS

Published Date

  • November 2022

Published In

Volume / Issue

  • 169 /

Start / End Page

  • 107523 -

PubMed ID

  • 36137427

Electronic International Standard Serial Number (EISSN)

  • 1873-6750

International Standard Serial Number (ISSN)

  • 0160-4120

Digital Object Identifier (DOI)

  • 10.1016/j.envint.2022.107523


  • eng