Magnesium Supplementation as a Nutritional Intervention in Sarcopenia (SARCOMAG)

Effects of Magnesium Supplementation on Muscle Strength, Muscle Mass, and Physical Performance in Sarcopenic Individuals

Sarcopenia is a progressive condition common in older adults and is characterized by loss of muscle strength, muscle mass, and physical performance. It is associated with an increased risk of falls, disability, reduced independence, and poorer quality of life. Nutritional interventions are recommended as part of sarcopenia management; however, evidence regarding the role of specific micronutrients remains limited. Magnesium is an essential mineral involved in muscle contraction, neuromuscular function, energy production, and inflammation regulation. Low magnesium status is frequent in older adults and may contribute to muscle impairment and physical decline.

This study aims to evaluate the effects of magnesium supplementation on muscle strength, muscle mass, and physical performance in older adults with sarcopenia living in the eastern Algarve region of Portugal. In addition, the study will assess the prevalence of low magnesium status and sarcopenia in this population.

The study will be conducted in two phases. In the first, observational phase, community-dwelling adults aged 70 years or older will be assessed for sarcopenia according to established diagnostic criteria. Blood samples will be collected to measure serum and erythrocyte magnesium levels and C-reactive protein as an inflammatory marker. Participants diagnosed with sarcopenia and presenting low magnesium levels will be eligible for the second phase.

In the second phase, eligible participants will be randomly assigned to receive either oral magnesium supplementation (400 mg/day of magnesium citrate) or a placebo for 12 weeks, in a double-blind and controlled design. After the intervention period, participants will be reassessed for muscle strength, muscle mass, physical performance, magnesium status, and inflammation.

The results of this study are expected to clarify the role of magnesium supplementation as a nutritional strategy in sarcopenia. Findings may contribute to improving nutritional recommendations and supporting interventions aimed at preserving muscle health, physical function, and quality of life in older adults.

Study Overview

• Status: Not yet recruiting
• Conditions: Sarcopenia
• Intervention / Treatment: Other: Placebo; Dietary supplement: Citrate Magnesium Supplementation

• Study Type: Interventional
• Enrollment (Estimated): 352
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Dina F João; Phone Number: +351961647475; Email: drjoao@ualg.pt

Study Locations

• Portugal
  • Faro District
    • Faro, Faro District, Portugal, 8005-139
      • Escola Superior de Saúde - Universidade do Algarve
      • Contact: Dina F João; Phone Number: +351961647475; Email: drjoao@ualg.pt
      • Principal Investigator: Dina F João

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 70 years or older
• Community-dwelling individuals residing in the eastern Algarve region of Portugal
• Not hospitalized at the time of recruitment
• Ability to participate in study assessments, regardless of mobility status
• Ability to provide written informed consent, either personally or via a legally authorized representative when applicable
• Adequate cognitive ability to collaborate with study procedures, as determined by screening assessment

Exclusion Criteria:

• Alcoholism
• Acute gastrointestinal conditions with symptoms of diarrhea and/or vomiting
• Presence of conditions associated with magnesium imbalance, including: Electrolyte disorders, Hyperthyroidism, Type 1 diabetes mellitus, Renal disease, Hyperaldosteronism, Short bowel syndrome or history of intestinal resection, Gastric bypass surgery
• Use of medications known to affect magnesium metabolism, including: Loop or thiazide diuretics (e.g., furosemide, thiazides), Proton pump inhibitors (e.g., omeprazole, pantoprazole, esomeprazole), Cytotoxic agents (e.g., cisplatin, carboplatin, gallium nitrate), Antimicrobial agents such as aminoglycosides, Immunosuppressive agents, Beta-adrenergic agonists (e.g., theophylline, salbutamol, rimiterol), Cetuximab, Cyclosporine A, Pamidronate.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Participants assigned to the placebo comparator group will receive an oral placebo administered daily for 12 weeks. The placebo consists of capsules containing microcrystalline cellulose, an inert substance with no known biological effects. The placebo capsules are identical in appearance, taste, and packaging to the magnesium supplement, ensuring blinding of participants and investigators. Participants will be instructed to take the capsules according to the same schedule as the intervention group. Adherence will be monitored through capsule count at follow-up visits.	Other: Placebo; Participants assigned to the placebo comparator arm will receive an oral placebo administered daily for 12 weeks. The placebo consists of capsules containing microcrystalline cellulose, an inert substance with no known physiological or therapeutic effects. The placebo capsules are identical in appearance, taste, and packaging to the magnesium supplement to ensure blinding of participants and investigators. The dosing schedule will be the same as that used in the experimental group. Adherence to the intervention will be monitored by capsule count at follow-up visits, and participants will be observed regularly for tolerability and safety.
Experimental: Magnesium Supplementation; Participants assigned to the experimental arm will receive oral magnesium supplementation administered daily for a period of 12 weeks. The intervention consists of magnesium citrate capsules providing a total daily dose of 400 mg of elemental magnesium. The supplement will be taken according to a standardized dosing schedule identical to that of the placebo group. Magnesium citrate was selected due to its favorable bioavailability. Participants and investigators will remain blinded to treatment allocation throughout the study. Adherence to the intervention will be assessed by capsule count at follow-up visits, and participants will be monitored regularly for tolerability and potential adverse events.	Dietary supplement: Citrate Magnesium Supplementation; Participants assigned to the experimental arm will receive oral magnesium supplementation administered daily for 12 weeks. The intervention consists of magnesium citrate capsules providing a total daily dose of 400 mg of elemental magnesium. The supplement will be taken according to a standardized dosing schedule identical to that of the placebo group. Magnesium citrate was selected due to its favorable bioavailability. Participants, investigators, and outcome assessors will remain blinded to group assignment throughout the study. Adherence to the intervention will be assessed by capsule count at follow-up visits, and participants will be monitored regularly for tolerability and potential adverse events.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle Strength	Change in muscle strength assessed by handgrip strength using a calibrated handgrip dynamometer. Handgrip strength will be measured in a seated position, with the elbow flexed at 90 degrees, following standardized procedures. Three measurements will be performed on the non-dominant hand (or dominant hand if necessary), with the highest value recorded. Muscle strength will be evaluated at baseline and after 12 weeks of intervention.	Baseline and 12 weeks
Muscle Mass	Change in muscle mass assessed by bioelectrical impedance analysis, including appendicular muscle mass and muscle mass adjusted for height. Measurements will be performed at baseline and after 12 weeks of intervention.	Baseline and 12 weeks
Physical Performance	Change in physical performance assessed by the 4-meter gait speed test, conducted according to standardized procedures. Performance will be assessed at baseline and after 12 weeks of intervention.	Baseline and 12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serum Magnesium Levels	Change in serum magnesium concentration measured from blood samples using standard laboratory procedures. Serum magnesium levels will be assessed at baseline and after 12 weeks of intervention.	Baseline and 12 weeks
Erythrocyte Magnesium Levels	Change in intracellular magnesium status assessed by erythrocyte magnesium concentration measured from blood samples using validated laboratory methods. Measurements will be performed at baseline and after 12 weeks of intervention.	Baseline and 12 weeks
Inflammation	Change in systemic inflammation assessed by serum C-reactive protein (CRP) concentration measured using standard laboratory methods. CRP levels will be evaluated at baseline and after 12 weeks of intervention.	Baseline and 12 weeks
Adherence to Supplementation	Adherence to the prescribed intervention assessed by capsule count, calculated as the proportion of capsules consumed during the 12-week intervention period.	Up to 12 weeks
Safety and Tolerability	Occurrence of adverse events and tolerability of magnesium supplementation or placebo assessed through participant reporting and regular monitoring during the intervention period.	Up to 12 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prevalence of Hypomagnesemia	Prevalence of low magnesium status determined by serum and/or erythrocyte magnesium concentrations below established reference values at baseline.	Baseline
Prevalence of Sarcopenia	Prevalence of sarcopenia determined at baseline according to the European Working Group on Sarcopenia in Older People (EWGSOP) diagnostic criteria.	Baseline

Collaborators and Investigators

• Sponsor: Escola Superior de Saúde - Universidade do Algarve

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): January 31, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: April 29, 2026
• First Submitted That Met QC Criteria: April 29, 2026
• First Posted (Actual): May 5, 2026

Study Record Updates

• Last Update Posted (Actual): May 8, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Supplementation; Older Adults; Aging; Sarcopenia; Muscle Strength; Magnesium; Muscle Mass; Physical Performance; Hypomagnesemia; Nutritional Intervention
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Pathological Conditions, Anatomical; Muscular Atrophy; Atrophy; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Sarcopenia
• Other Study ID Numbers: UAIF201/2025FARO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Individual participant data will not be shared due to ethical and data protection constraints. The study involves an older population considered potentially vulnerable, and informed consent for participation did not include consent for data sharing beyond the research team. In addition, the risk of re-identification cannot be fully excluded given the detailed clinical and contextual data collected. Data will be used exclusively for the purposes defined in the approved protocol and in accordance with applicable data protection regulations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No