Lever
Lifestyle
- Regular weight-bearing exercise
- Adequate sunlight exposure
- Avoid excessive alcohol consumption
Critical Thresholds
Seek immediate emergency care if calcium < 1.8 mmol/L or > 3.0 mmol/L due to risk of severe complications.
Critical Low1.8 mmol/LCritical High3 mmol/L
Blutwerte · Marker
Calcium
Serum Calcium · Ca · Kalzium
ElektrolyteZeitabhängig
- Einheit:
- mmol/L
- Abbreviation
- Ca2+
Calcium test quantifies the total serum calcium, including ionized calcium, protein-bound calcium, and calcium complexed with anions.
Reference Ranges
Reference
2.1–2.6mmol/L
1.8
2.1
2.2
2.5
2.6
3
LowNormalHigh
Reference
Optimal
Critical
Unit · mmol/LReference ranges may vary slightly by age and sex; fasting status can affect levels.
Overview
Übersicht
Calcium (Ca2+), also known as serum calcium, is a vital electrolyte that plays a crucial role in numerous biological processes, including bone mineralization, neuromuscular function, and blood coagulation. It exists in the blood in three forms: ionized, bound to proteins (primarily albumin), and complexed with anions. Researchers have found that the ionized form is the most biologically active and tightly regulated by parathyroid hormone (PTH), vitamin D, and calcitonin. Clinically, calcium levels are significant in diagnosing and managing conditions such as hypoparathyroidism, hyperparathyroidism, osteoporosis, and renal disease. Elevated calcium levels, or hypercalcemia, can indicate primary hyperparathyroidism or malignancy, while low levels, or hypocalcemia, may result from hypoparathyroidism, vitamin D deficiency, or renal failure. For athletes and biohackers, maintaining optimal calcium levels is essential for bone health and muscle function, potentially impacting performance and recovery. However, researchers observed that calcium levels can be influenced by factors such as age, sex, and dietary intake, and may fluctuate based on time of day and fasting status. Therefore, accurate assessment requires standardized testing conditions, and interpretation should consider these confounding factors.
Klinische Bedeutung
Elevated calcium levels may indicate hyperparathyroidism, malignancy, or vitamin D intoxication. Reduced calcium levels can suggest hypoparathyroidism, vitamin D deficiency, or chronic kidney disease.
Dynamics
Trend Interpretation
Rising Values
Progressively rising calcium levels suggest possible hyperparathyroidism or malignancy. Re-test within 4 weeks if elevated.
Falling Values
Falling calcium levels may indicate worsening renal function or malabsorption issues.
Re-test Interval
4 weeks if outside optimal range
Etiology
Causes — High & Low
Cause
Elevated Levels
- Primary hyperparathyroidism
- Malignancy
- Vitamin D intoxication
- Thiazide diuretics
- Prolonged immobilization
Cause
Low Levels
- Hypoparathyroidism
- Vitamin D deficiency
- Chronic kidney disease
- Hypomagnesemia
- Acute pancreatitis
Protocol
How to Optimize
Lever
Nutrition
- Consume calcium-rich foods like dairy
- Include leafy greens
- Ensure adequate protein intake
Lever
Supplementation
- Calcium carbonate
- Vitamin D
- Magnesium
Note:
Consult a healthcare provider before starting supplements, especially if you have a history of kidney stones or hypercalcemia.
Testing Guidelines
✓Fasting Not Required
🕐Time-Sensitive
Calcium levels can vary throughout the day; morning samples may be more consistent.
Testing Frequency
Annually for healthy adults, more frequently if managing a related condition.
Interfering Factors
- Recent intense exercise
- High protein intake
- Certain medications like lithium
Related Peptides & Hormones
Parathyroid Hormone
hormoneMay affect
Open Research Questions
Current research suggests that reference ranges for serum calcium may vary significantly based on demographic factors, and optimal targets for calcium levels in specific populations, such as those with hypoparathyroidism or osteoporosis, remain debated. Researchers have not yet established the long-term efficacy and safety of emerging therapies targeting calcium homeostasis. Additionally, clinical questions regarding the best monitoring strategies for calcium levels during pregnancy and lactation in patients with hypoparathyroidism remain unanswered.
21 Research Publications
242
Total Citations
3
Human/RCT
1.8
Avg. Influence
2025
Latest
Sort
Filter
01Top
#01
Ionized Calcium in the ICU: Should It Be Measured and Corrected?
ReviewInfluence3.0
70
Researchers discussed the measurement of ionized calcium in ICU patients, finding that many have abnormal levels. They observed that while measuring ionized calcium is common, its correction may not always be beneficial and could even be harmful in critical illness.
02Top
#02
Hypocalcemia in the newborn.
ReviewInfluence2.0
61
This study examined hypocalcemia in newborns, noting that it is a common clinical issue. Researchers found that healthy term infants typically experience a physiological drop in calcium levels shortly after birth, while high-risk neonates may require calcium supplementation.
03Top
#03
Management of Hypoparathyroidism.
ReviewInfluence3.0
46
This study examined the management of hypoparathyroidism, a condition characterized by low calcium levels. Researchers found that conventional therapy with calcium and vitamin D aims to maintain serum calcium levels but has limitations, including fluctuations and complications. They also noted that parathyroid hormone replacement may be considered when conventional therapy is unsatisfactory.
04
#04
Clinical value of serum calcium in elderly patients with sepsis.
HumanInfluence1.0
19
This study explored the clinical significance of serum calcium levels in elderly patients with sepsis. Researchers found that lower serum calcium levels were associated with increased severity of sepsis and higher mortality rates. They also noted a negative correlation between serum calcium and procalcitonin levels.
05
#05
Mechanosensitivity of microdomain calcium signalling in the heart.
ReviewInfluence1.0
17
Researchers examined calcium signaling in cardiac myocytes, noting its importance in heart function. They found that local calcium gradients are crucial for contraction and that dysregulation can lead to serious cardiac issues, highlighting the mechanosensitivity of calcium signaling.
06
#06
The Laboratory and Clinical Perspectives of Magnesium Imbalance.
ReviewInfluence1.0
15
Researchers highlighted the significance of magnesium in relation to calcium homeostasis and its role in various bodily functions. The study pointed out that magnesium imbalance can coexist with other electrolyte disorders, affecting clinical outcomes.
07
#07
Pathogenic roles of altered calcium channels and transporters in colon tumorogenesis.
Review
11
This review summarized the roles of calcium channels and transporters in colorectal cancer. Researchers observed that altered calcium signaling may contribute to tumorigenesis, suggesting that targeting calcium pathways could be a potential therapeutic strategy.
08
#08
[Clinical significance of calcium sensitizer].
Review
3
This article reviewed the clinical significance of calcium sensitizers in heart failure treatment. Researchers found that while these agents were expected to improve outcomes, trials have not met expectations, indicating a need for better-targeted therapies.
09
#09
[Hypocalcemia].
Review
This study defined hypocalcemia as a serum calcium level below the reference range and identified various causes, including vitamin D deficiency and renal insufficiency. Researchers noted that the management of hypocalcemia depends on its causes and severity.
10
#10
[Hypocalcemia, emergency or not ?].
Review
This article reviewed hypocalcemia, defining it and discussing its clinical implications. Researchers found that prompt management is crucial to normalize serum calcium and address symptoms, emphasizing the need for a thorough understanding of calcium metabolism.
Clinical Trials (16)
16
Total Trials
14,255
Total Enrolled
Pilot Validation of the STELA Preventive Medicine Platform to Reduce Modifiable Health Risk Factors in Adults (CPM-STELA)
NCT07551960ENROLLING_BY_INVITATION
Sponsor
Nemocnice AGEL Trinec-Podlesi a.s.
Enrollment
100
Started
2026
Primary outcome
Change in AGEL Gamification Index (AGI) from Baseline to 12 Months
Cardiovascular Risk FactorsInsulin ResistanceObesityDyslipidemiasMetabolic Syndrome
Effective Dosing of Burosumab in XLH
NCT07183579RECRUITING
Sponsor
University of Nottingham
Enrollment
120
Started
2025
Primary outcome
The proportion of patients who achieved biochemical control (serum phosphate above the lower limit of the local reference range) on a dose of less than 0.8 mg/kg per dose of Burosumab.
X-linked Hypophosphatemia (XLH)
Optimization of Percutaenous Coronary Intervention With Liberal Use of Post-dilatation
NCT06558474RECRUITING
Sponsor
Cathreine BV
Enrollment
12,000
Started
2023
Primary outcome
Occurrence of target vessel revascularization, myocardial infarction and all-cause mortality
Coronary Artery Disease
Home-based Transcranial Direct Current Stimulation in Postpartum Depression: the Feasibility Study and Pilot Study
NCT05046405NOT_YET_RECRUITING
Sponsor
Ana Ganho Ávila
Enrollment
50
Started
2022
Primary outcome
Feasibility of the intervention - Number of completed tDCS applications
Postnatal Depression
Effect of Evolocumab on Coronary Plaque Characteristics
Sponsor
Annapoorna Kini
Enrollment
137
Started
2021
Primary outcome
Change in Minimal Fibrous Cap Thickness (FCT)
Coronary Artery Disease
Tusamitamab Ravtansine Monotherapy and in Combination in Patients With CEACAM5-positive Advanced Solid Tumors
Sponsor
Sanofi
Enrollment
50
Started
2021
Primary outcome
Objective Response Rate (ORR)
Breast Cancer MetastaticPancreatic Carcinoma Metastatic
Acetazolamide Efficacy in Ataxia in PMM2-CDG
Sponsor
Mayo Clinic
Enrollment
25
Started
2021
Primary outcome
Efficacy of Acetazolamide on Ataxia Measured Via Miniature International Cooperative Ataxia Rating Scale (Mini-ICARS)
Pmm2-CDGCDG1A
Dasatinib for the Prevention of Oxaliplatin-Induced Neuropathy in Patients With Metastatic Gastrointestinal Cancer Receiving FOLFOX Chemotherapy With or Without Bevacizumab
Sponsor
Anne Noonan
Enrollment
9
Started
2020
Primary outcome
Recommended phase II dose (RP2D) of dasatinib
Advanced Colorectal CarcinomaMetastatic Colorectal CarcinomaStage IV Colorectal Cancer AJCC v8Stage IVA Colorectal Cancer AJCC v8Stage IVB Colorectal Cancer AJCC v8Stage IVC Colorectal Cancer AJCC v8Stage II Colon CancerStage II Rectal CancerStage III Colon CancerStage III Rectal CancerEsophageal CancerPancreatic CancerBile Duct CancerGastric CancerGall Bladder CancerSmall Bowel Adenocarcinoma
Study of Coronary Calcium Score as a Marker of Post-radiation Vascular Dysplasia in Adults Treated During Childhood for Cancer With Mediastinal Irradiation
NCT03604627RECRUITING
Sponsor
Gustave Roussy, Cancer Campus, Grand Paris
Enrollment
500
Started
2018
Primary outcome
Incidence of a calcium score
Childhood Cancer
Serum Catestatin Expression and Cardiometabolic Parameters in Patients With Congestive Heart Failure
NCT03389386COMPLETED
Sponsor
Josko Bozic
Enrollment
120
Started
2018
Primary outcome
Catestatin levels in blood serum
Heart Failure，Congestive
Extragonadal Effects of hCG on Calcium Homeostasis
Sponsor
Martin Blomberg Jensen
Enrollment
12
Started
2018
Primary outcome
Serum calcium
HypogonadismCalcium DisorderRenal Disease
PlacEntal Acute Atherosis RefLecting Subclinical Atherosclerosis
NCT05500989RECRUITING
Sponsor
Maastricht University Medical Center
Enrollment
226
Started
2016
Primary outcome
Relationship between placental acute atherosis and subclinical coronary atherosclerosis at 1 year postpartum
Pre-EclampsiaHELLP SyndromeIntrauterine Growth RestrictionPregnancy
Bone Demineralization Lesions in the Injured Marrow: Efficacy and Tolerability of Administration Early and Repeated the Zoledronic Acid. Comparative Study, Prospective, Double-blind Controlled (DBMZol)
Sponsor
Nantes University Hospital
Enrollment
12
Started
2012
Primary outcome
determine DMO distal femur at 36 months
Bone Demineralization Lesions in the Injured Marrow
Ultrasound Imaging Technique in Detecting Breast Microcalcifications in Patients Undergoing Biopsy for a Breast Abnormality
NCT03031561COMPLETED
Sponsor
Sidney Kimmel Comprehensive Cancer Center at Thomas Jefferson University
Enrollment
85
Started
2012
Primary outcome
Number of microcalcifications seen on MicroPure ultrasound
Breast CarcinomaMicrocalcification
Pulmonary Disease in Patients Referred for Coronary CT
NCT01734629COMPLETED
Sponsor
University of Sao Paulo General Hospital
Enrollment
205
Started
2011
Primary outcome
Coronary Calcium Score
Coronary Artery DiseaseAtherosclerosesCOPDRespiratory Diseases
Safety/Efficacy of Zoledronic Acid and Alendronate on Bone Metabolism in Postmenopausal Women With Osteoporosis
Sponsor
Novartis
Enrollment
604
Started
2006
Primary outcome
Change of Cross-linked N-telopeptide of Type I Collagen (NTx) Level Assessed as Standardized Area Under the Curve From Screening to Month 12 in the Intent-to-Treat Population
Osteoporosis
Publication Trend
Research publications about Calcium over time
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