Serum Vitamin D₃ Concentration, Sleep, and Cognitive Impairment among Older Adults in China

Abstract

Background: Cognitive decline in older adults has become one of the critical challenges to global health. This study aims to examine both cross-sectional and longitudinal associations of levels of serum 25-hydroxyvitamin D3 (25(OH)D3) (briefed as VD3) concentration and sleep quality/duration, especially their interactions, with risk of cognitive impairment among older adults in China. Methods: We utilized a special subsample of adults aged 65–105 years (individuals = 3412, observations = 4816) from eight provinces in China derived from the 2011/2012 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey. Cognitive impairment was measured by the Mini-Mental State Examination scale. Sleep quality was classified as good versus fair/poor, and sleep duration was classified into short (3 sufficiency are positively associated with good cognitive function. VD3 sufficiency could enhance the associations between sleep and cognitive impairment.

Keywords

• serum 25-hydroxyvitamin D₃ (25(OH)D₃)
• sleep quality
• sleep duration
• cognitive impairment
• older adults
• oldest-old