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Updated: May 10, 2026
Measuring Cardiac Autonomic Nervous System (ANS) Activity in Children
Published on: April 29, 2013
Vitamin D levels are associated with cardiac autonomic activity in healthy humans
Michelle C Mann1, Derek V Exner, Brenda R Hemmelgarn
1University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada. mcmann@ucalgary.ca
Insights
Vitamin D deficiency impacts cardiac autonomic activity at rest. Low vitamin D levels are linked to unfavorable heart autonomic responses during stress, potentially increasing cardiovascular risk.
Area of Science:
- Cardiology
- Endocrinology
- Physiology
Background:
- Vitamin D deficiency is a global issue and a cardiovascular risk factor, especially in chronic kidney disease (CKD) patients.
- Individuals with CKD exhibit abnormal cardiac autonomic nervous system activity, contributing to high cardiovascular mortality.
- The direct link between vitamin D deficiency and cardiac autonomic regulation in humans remains unexplored.
Purpose of the Study:
- To investigate the association between vitamin D deficiency and cardiac autonomic nervous system activity in healthy individuals.
- To explore the impact of different vitamin D metabolites on sympathovagal balance.
- To determine if vitamin D status influences cardiovascular autonomic responses during a physiological stressor.
Main Methods:
- Thirty-four healthy subjects were divided into vitamin D deficient and non-deficient groups.
- Cardiac autonomic activity was assessed using power spectral analysis of electrocardiogram recordings.
- Responses were measured during a graded angiotensin II challenge to evaluate sympathovagal balance (LF:HF ratio) and vagal contribution (HF).
Main Results:
- Vitamin D deficiency was associated with suppressed resting sympathovagal balance (p=0.02).
- Low 1,25-dihydroxy vitamin D levels correlated with reduced vagal control (HF, p=0.05) during angiotensin II challenge.
- Participants with the lowest 1,25-dihydroxy vitamin D levels showed altered sympathovagal balance (LF:HF, p=0.043) under stress.
Conclusions:
- Vitamin D deficiency is linked to suppressed resting cardiac autonomic activity.
- Low levels of 1,25-dihydroxy vitamin D are associated with adverse cardiac autonomic responses during acute stress.
- These findings suggest a potential mechanism linking low vitamin D status to elevated cardiovascular risk.
Unlabelled:
Vitamin D deficiency (≤50nmol/L 25-hydroxy vitamin D) is a cardiovascular (CV) risk factor that affects approximately one billion people worldwide, particularly those affected by chronic kidney disease (CKD). Individuals with CKD demonstrate abnormal cardiac autonomic nervous system activity, which has been linked to the significant rates of CV-related mortality in this population. Whether vitamin D deficiency has a direct association with regulation of cardiac autonomic activity has never been explored in humans.
Methods:
Thirty-four (34) healthy, normotensive subjects were studied and categorized based on 25-hydroxy vitamin D deficiency (deficient vs. non-deficient, n = 7 vs. 27), as well as 1,25-dihydroxy vitamin D levels (above vs. below 25th percentile, n = 8 vs. 26). Power spectral analysis of electrocardiogram recordings provided measures of cardiac autonomic activity across low frequency (LF) and high frequency (HF, representative of vagal contribution) bands, representative of the sympathetic and vagal limbs of the autonomic nervous system when transformed to normalized units (nu), respectively, as well as overall cardiosympathovagal balance (LF:HF) during graded angiotensin II (AngII) challenge (3 ng/kg/min × 30 min, 6 ng/kg/min × 30 min).
Results:
At baseline, significant suppression of sympathovagal balance was observed in the 25-hydroxy vitamin D-deficient participants (LF:HF, p = 0.02 vs. non-deficient), although no other differences were observed throughout AngII challenge. Participants in the lowest 1,25-dihydroxy VD quartile experienced significant withdrawal of inhibitory vagal control, as well as altered overall sympathovagal balance throughout AngII challenge (HF, mean difference = -6.98 ± 3 nu, p = 0.05; LF:HF, mean difference = 0.34 ± 0.1, p = 0.043 vs. above 25th percentile).
Conclusions:
Vitamin D deficiency is associated with suppression of resting cardiac autonomic activity, while low 1,25-dihydroxy vitamin D levels are associated with unfavourable cardiac autonomic activity during an acute AngII stressor, offering a potential pathophysiological mechanism that may be acting to elevate CV risk in in populations with low vitamin D status.
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