The association between 25-hydroxyvitamin D levels and children’s sleep–wake patterns: a prospective cohort study

Abstract Objective To explore the association between vitamin D in cord blood or in venous blood and children's sleep-wake patterns at two years of age. Methods Data were from 209 children in a birth cohort, Shanghai Sleep Birth Cohort Study (SSBC). 25-Hydroxyvitamin D (25(OH)D) was assessed in cord blood and venous blood samples at two years of age by electrochemiluminescence immunoassay. Children's sleep-wake patterns were measured with the Brief Infant Sleep Questionnaire (BISQ) and Acti-Watch at two years of age. Results The prevalence of vitamin D deficiency (defined as Conclusion We found that not cord blood 25(OH)D level but two-year-old 25(OH)D level was associated with children's sleep-wake patterns at two years of age. These findings suggest more attention should be paid to the assessment of 25(OH)D levels in children with short sleep duration.