Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking status

ObjectiveTo investigate the association between vitamin C intake and cognitive function in U.S. older adults, focusing on dose–response characteristics and effect modification of key subgroups.MethodsUtilizing data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES), this cr...

Full description

Saved in:
Bibliographic Details
Main Authors: Xingchen He, Yijia Lin, Xinyi Wu, Min Li, Tianyu Zhong, Yanhong Zhang, Xuliang Weng
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-06-01
Series:Frontiers in Nutrition
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fnut.2025.1585863/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850232844203327488
author Xingchen He
Yijia Lin
Xinyi Wu
Min Li
Tianyu Zhong
Yanhong Zhang
Yanhong Zhang
Xuliang Weng
Xuliang Weng
author_facet Xingchen He
Yijia Lin
Xinyi Wu
Min Li
Tianyu Zhong
Yanhong Zhang
Yanhong Zhang
Xuliang Weng
Xuliang Weng
author_sort Xingchen He
collection DOAJ
description ObjectiveTo investigate the association between vitamin C intake and cognitive function in U.S. older adults, focusing on dose–response characteristics and effect modification of key subgroups.MethodsUtilizing data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES), this cross-sectional study included 2,801 adults aged ≥ 60 years. Total vitamin C intake was assessed via standardized 24-h dietary recalls and supplement questionnaires. Cognitive function was evaluated using the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word Learning Test, Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). Multivariate adjusted linear regression models, smooth curve fitting, and stratified regression analyses were employed to examine associations and effect modification.ResultsOur analysis revealed a nonlinear dose–response relationship between vitamin C intake and cognitive performance. In fully adjusted models, participants in the highest intake quartile (Q4) showed significantly better performance on the Auditory Fluency Test (AFT; β = 1.11, 95% CI: 0.37–1.85) and the Digit Symbol Substitution Test (DSST; β = 3.35, 95% CI: 1.49–5.21) compared to those in the lowest quartile (Q1). Threshold analyses indicated that cognitive protection for DSST peaked at an intake of 500 mg/day, while AFT benefits plateaued at 120 mg/day. Stratified analyses further demonstrated that the cognitive benefits of vitamin C were more pronounced among smokers (DSST: β = 0.59 per 100 mg/day, p = 0.0009), with no significant associations observed in non-smokers.ConclusionVitamin C intake is associated with improved cognitive function in older U.S. adults, with distinct dose-dependent and domain-specific threshold effects. Smoking status significantly modifies this relationship, suggesting that personalized supplementation strategies targeting smokers may enhance cognitive protection.
format Article
id doaj-art-3a8f4da48109487aba7502cb2a376180
institution OA Journals
issn 2296-861X
language English
publishDate 2025-06-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Nutrition
spelling doaj-art-3a8f4da48109487aba7502cb2a3761802025-08-20T02:03:04ZengFrontiers Media S.A.Frontiers in Nutrition2296-861X2025-06-011210.3389/fnut.2025.15858631585863Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking statusXingchen He0Yijia Lin1Xinyi Wu2Min Li3Tianyu Zhong4Yanhong Zhang5Yanhong Zhang6Xuliang Weng7Xuliang Weng8The Affiliated Guangzhou Hospital of TCM of Guangzhou University of Chinese Medicine, Guangzhou, ChinaThe Affiliated Guangzhou Hospital of TCM of Guangzhou University of Chinese Medicine, Guangzhou, ChinaThe Affiliated Guangzhou Hospital of TCM of Guangzhou University of Chinese Medicine, Guangzhou, ChinaThe Affiliated Guangzhou Hospital of TCM of Guangzhou University of Chinese Medicine, Guangzhou, ChinaThe Affiliated Guangzhou Hospital of TCM of Guangzhou University of Chinese Medicine, Guangzhou, ChinaThe Affiliated Guangzhou Hospital of TCM of Guangzhou University of Chinese Medicine, Guangzhou, ChinaSleep Research Institute of Traditional Chinese Medicine, Guangzhou Medical University, Guangzhou, ChinaThe Affiliated Guangzhou Hospital of TCM of Guangzhou University of Chinese Medicine, Guangzhou, ChinaSleep Research Institute of Traditional Chinese Medicine, Guangzhou Medical University, Guangzhou, ChinaObjectiveTo investigate the association between vitamin C intake and cognitive function in U.S. older adults, focusing on dose–response characteristics and effect modification of key subgroups.MethodsUtilizing data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES), this cross-sectional study included 2,801 adults aged ≥ 60 years. Total vitamin C intake was assessed via standardized 24-h dietary recalls and supplement questionnaires. Cognitive function was evaluated using the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word Learning Test, Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). Multivariate adjusted linear regression models, smooth curve fitting, and stratified regression analyses were employed to examine associations and effect modification.ResultsOur analysis revealed a nonlinear dose–response relationship between vitamin C intake and cognitive performance. In fully adjusted models, participants in the highest intake quartile (Q4) showed significantly better performance on the Auditory Fluency Test (AFT; β = 1.11, 95% CI: 0.37–1.85) and the Digit Symbol Substitution Test (DSST; β = 3.35, 95% CI: 1.49–5.21) compared to those in the lowest quartile (Q1). Threshold analyses indicated that cognitive protection for DSST peaked at an intake of 500 mg/day, while AFT benefits plateaued at 120 mg/day. Stratified analyses further demonstrated that the cognitive benefits of vitamin C were more pronounced among smokers (DSST: β = 0.59 per 100 mg/day, p = 0.0009), with no significant associations observed in non-smokers.ConclusionVitamin C intake is associated with improved cognitive function in older U.S. adults, with distinct dose-dependent and domain-specific threshold effects. Smoking status significantly modifies this relationship, suggesting that personalized supplementation strategies targeting smokers may enhance cognitive protection.https://www.frontiersin.org/articles/10.3389/fnut.2025.1585863/fullvitamin Ccognitive functionNHANESolder adultsdose–response relationshipsmoking status
spellingShingle Xingchen He
Yijia Lin
Xinyi Wu
Min Li
Tianyu Zhong
Yanhong Zhang
Yanhong Zhang
Xuliang Weng
Xuliang Weng
Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking status
Frontiers in Nutrition
vitamin C
cognitive function
NHANES
older adults
dose–response relationship
smoking status
title Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking status
title_full Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking status
title_fullStr Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking status
title_full_unstemmed Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking status
title_short Vitamin C intake and cognitive function in older U.S. adults: nonlinear dose–response associations and effect modification by smoking status
title_sort vitamin c intake and cognitive function in older u s adults nonlinear dose response associations and effect modification by smoking status
topic vitamin C
cognitive function
NHANES
older adults
dose–response relationship
smoking status
url https://www.frontiersin.org/articles/10.3389/fnut.2025.1585863/full
work_keys_str_mv AT xingchenhe vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT yijialin vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT xinyiwu vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT minli vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT tianyuzhong vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT yanhongzhang vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT yanhongzhang vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT xuliangweng vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus
AT xuliangweng vitamincintakeandcognitivefunctioninolderusadultsnonlineardoseresponseassociationsandeffectmodificationbysmokingstatus