Eur J Nutr DOI 10.1007/s00394-015-0968-0
ORIGINAL CONTRIBUTION
Serum 25‑hydroxyvitamin D is associated with reduced verbal episodic memory in healthy, middle‑aged and older adults Virginie Lam1,2 · Matthew A. Albrecht1,2,3 · Ryusuke Takechi1,2 · Prachya Prasopsang4 · Ya Ping Lee4 · Jonathan K. Foster5,6 · John C. L. Mamo1,2
Received: 2 March 2015 / Accepted: 16 June 2015 © Springer-Verlag Berlin Heidelberg 2015
Abstract Background There is increasing evidence supporting an association of higher serum vitamin D concentration with better cognitive performance in older individuals. However, to date, consideration of the putative association between vitamin D and cognition has been based principally on studies investigating clinical participant samples manifesting vitamin D deficiency, particularly in older people. Moreover, relationships between vitamin D and cognition are typically not considered in the context of counter-regulatory calcium-modulating hormones or calcium homeostasis. Objective Serum vitamin D/bioactive (ionised) calcium/ parathyroid hormone homeostasis was considered in the
Virginie Lam and Matthew A. Albrecht have contributed equally to this work. * John C. L. Mamo [email protected] 1
School of Public Health, Curtin University, Perth, WA, Australia
2
Curtin Health Innovation Research Institute ‑ Biosciences, Curtin University, Perth, WA, Australia
3
Maryland Psychiatric Research Center, Department of Psychiatry, School of Medicine, University of Maryland, Baltimore, MD, USA
4
School of Pharmacy, Perth, WA, Australia
5
School of Psychology and Speech Pathology, Curtin University, Perth, WA, Australia
6
Neurosciences Unit, Health Department of Western Australia, Perth, WA, Australia
context of cognitive performance in healthy, middle-aged and older individuals. Design A cross-sectional sample of 179 participants between the ages of 47–84 years was recruited for this study (114 females, 65 males). Participants provided fasting blood samples for analysis of serum 25-hydroxyvitamin D levels, ionised calcium (iCa) and parathyroid hormone (PTH) and completed cognitive measures of verbal episodic learning and memory. Results Serum 25-hydroxyvitamin D concentrations were negatively associated (with and without covariates of age, gender, depression and NART scores, iCa, and PTH) with measures of verbal episodic learning and memory, in particular with trial 5 of the Rey Auditory Verbal Learning Test (RAVLT) and long-delay free recall on the RAVLT. Conclusion Overall, the findings from this study suggest an association between higher vitamin D status and poorer performance on verbal episodic memory in middle-aged and older individuals with normal vitamin D–calcium–PTH homeostasis. Despite requiring replication in other participant samples, this is a potentially important finding as it indicates that it may not be beneficial from a cognitive perspective to provide vitamin D supplements in individuals with already adequate vitamin D status. Keywords Vitamin D · Serum 25-hydroxyvitamin D · Cognition · Ionised calcium · Parathyroid hormone · Verbal episodic memory Abbreviations iCa Ionised calcium PTH Parathyroid hormone 25(OH)D 25-Hydroxyvitamin D RAVLT Rey Auditory Verbal Learning Test DASS Depression, Anxiety and Stress Scales
13
NART National Adult Reading Test-Second Edition CDR Cognitive drug research test battery
Introduction There is accumulating evidence supporting an association of higher serum vitamin D concentration with better cognitive performance in older individuals [1–4]. Putative mechanisms for the purported effects include enhanced neurotransmission, increased synaptogenesis or neurogenesis and/or inhibition of degenerative processes including apoptosis [5, 6]. However, consideration of the relationship between vitamin D and cognitive status in the extant literature has been based principally on studies investigating individuals manifesting vitamin D deficiency, particularly in older people. For example, just under half of the sample cohort in [2] report vitamin D deficiency (
ORIGINAL CONTRIBUTION
Serum 25‑hydroxyvitamin D is associated with reduced verbal episodic memory in healthy, middle‑aged and older adults Virginie Lam1,2 · Matthew A. Albrecht1,2,3 · Ryusuke Takechi1,2 · Prachya Prasopsang4 · Ya Ping Lee4 · Jonathan K. Foster5,6 · John C. L. Mamo1,2
Received: 2 March 2015 / Accepted: 16 June 2015 © Springer-Verlag Berlin Heidelberg 2015
Abstract Background There is increasing evidence supporting an association of higher serum vitamin D concentration with better cognitive performance in older individuals. However, to date, consideration of the putative association between vitamin D and cognition has been based principally on studies investigating clinical participant samples manifesting vitamin D deficiency, particularly in older people. Moreover, relationships between vitamin D and cognition are typically not considered in the context of counter-regulatory calcium-modulating hormones or calcium homeostasis. Objective Serum vitamin D/bioactive (ionised) calcium/ parathyroid hormone homeostasis was considered in the
Virginie Lam and Matthew A. Albrecht have contributed equally to this work. * John C. L. Mamo [email protected] 1
School of Public Health, Curtin University, Perth, WA, Australia
2
Curtin Health Innovation Research Institute ‑ Biosciences, Curtin University, Perth, WA, Australia
3
Maryland Psychiatric Research Center, Department of Psychiatry, School of Medicine, University of Maryland, Baltimore, MD, USA
4
School of Pharmacy, Perth, WA, Australia
5
School of Psychology and Speech Pathology, Curtin University, Perth, WA, Australia
6
Neurosciences Unit, Health Department of Western Australia, Perth, WA, Australia
context of cognitive performance in healthy, middle-aged and older individuals. Design A cross-sectional sample of 179 participants between the ages of 47–84 years was recruited for this study (114 females, 65 males). Participants provided fasting blood samples for analysis of serum 25-hydroxyvitamin D levels, ionised calcium (iCa) and parathyroid hormone (PTH) and completed cognitive measures of verbal episodic learning and memory. Results Serum 25-hydroxyvitamin D concentrations were negatively associated (with and without covariates of age, gender, depression and NART scores, iCa, and PTH) with measures of verbal episodic learning and memory, in particular with trial 5 of the Rey Auditory Verbal Learning Test (RAVLT) and long-delay free recall on the RAVLT. Conclusion Overall, the findings from this study suggest an association between higher vitamin D status and poorer performance on verbal episodic memory in middle-aged and older individuals with normal vitamin D–calcium–PTH homeostasis. Despite requiring replication in other participant samples, this is a potentially important finding as it indicates that it may not be beneficial from a cognitive perspective to provide vitamin D supplements in individuals with already adequate vitamin D status. Keywords Vitamin D · Serum 25-hydroxyvitamin D · Cognition · Ionised calcium · Parathyroid hormone · Verbal episodic memory Abbreviations iCa Ionised calcium PTH Parathyroid hormone 25(OH)D 25-Hydroxyvitamin D RAVLT Rey Auditory Verbal Learning Test DASS Depression, Anxiety and Stress Scales
13
NART National Adult Reading Test-Second Edition CDR Cognitive drug research test battery
Introduction There is accumulating evidence supporting an association of higher serum vitamin D concentration with better cognitive performance in older individuals [1–4]. Putative mechanisms for the purported effects include enhanced neurotransmission, increased synaptogenesis or neurogenesis and/or inhibition of degenerative processes including apoptosis [5, 6]. However, consideration of the relationship between vitamin D and cognitive status in the extant literature has been based principally on studies investigating individuals manifesting vitamin D deficiency, particularly in older people. For example, just under half of the sample cohort in [2] report vitamin D deficiency (
