Effect of Vitamin D on Body Composition and Functionality of Older Adults

Effect of Vitamin D Supplementation on Strength and Muscle Gain in Older Adults With Obesity in Miahuatlán de Porfirio Díaz, in Period 2023-2024

Older adults with obesity often experience a gradual loss of muscle mass and muscle strength, a condition sometimes described as sarcopenic obesity. This combination increases the risk of falls, disability, functional decline, and metabolic complications. Low levels of vitamin D are common in older adults and may contribute to reduced muscle function and poorer physical performance.

This study is designed to evaluate whether taking 10,000 International Units (IU) per day of vitamin D3 for 12 weeks can improve muscle strength and muscle mass in older adults with obesity living in southern Mexico. The study will also examine whether vitamin D3 supplementation influences body composition, physical performance, and serum levels of 25-hydroxyvitamin D.

Participants will complete assessments at the beginning and at the end of the 12-week period. These assessments include measurements of muscle strength, skeletal muscle mass, body fat percentage, and indicators of physical performance such as the Short Physical Performance Battery (SPPB). Additional measures of body composition and anthropometry, such as body mass index, waist circumference, and related indices, will also be recorded. Blood samples will be analyzed to determine vitamin D status.

All participants will receive daily oral vitamin D3 (cholecalciferol) throughout the 12-week intervention. The goal of the study is to understand whether improving vitamin D status can have a positive effect on muscle health and physical function in older adults with obesity.

The results from this research may help guide future strategies to prevent or reduce functional decline related to low muscle mass in older adults with obesity, particularly in rural regions of Mexico where vitamin D deficiency is common.

Study Overview

• Status: Completed
• Conditions: Obesity; Muscle Weakness; Vitamin D Deficiency; Sarcopenia; Aging; Sarcopenic Obesity; Obesity (Disorder); Sarcopenia in Elderly; Muscle Mass; Functional Decline; Age-Related Loss of Skeletal Muscle Mass; Older Adults (65 Years and Older); Muscle Strengh; Vitamin D 25-Hydroxylase Deficiency
• Intervention / Treatment: Dietary supplement: Vitamin D; Dietary supplement: Vitamin D placebo

Detailed Description

This randomized controlled study investigated the effects of vitamin D3 supplementation on muscle strength, body composition, and functional performance in older adults with obesity. Vitamin D deficiency is highly prevalent in this population and has been associated with reduced skeletal muscle mass, decreased physical performance, increased fat accumulation, and progression toward frailty. Improving vitamin D status may contribute to better musculoskeletal health and improved physical function.

Participants received 10,000 International Units (IU) per day of vitamin D3 for a total period of 12 weeks. All assessments were conducted at baseline and at week 12. Handgrip strength was measured using a Jamar hand dynamometer as an indicator of muscle strength. Skeletal muscle mass, body fat percentage, visceral fat index, metabolic age, and related measures were obtained via Bioelectrical Impedance Analysis (BIA). Anthropometric variables including weight, body mass index (BMI), waist circumference, abdominal volume index (AVI), and body adiposity index (BAI) were also recorded.

Functional status was assessed using the Short Physical Performance Battery (SPPB), a validated tool consisting of balance, gait speed, and chair stand tests. The SPPB ranges from 0 to 12 points, with higher scores indicating better physical performance.

Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were evaluated using standardized laboratory techniques to determine changes in vitamin D status associated with supplementation.

This study seeks to clarify whether vitamin D3 supplementation can improve muscle strength, muscle mass, functional performance, and body composition among older adults with obesity, and to better understand the role of vitamin D in age-related musculoskeletal decline.

• Study Type: Interventional
• Enrollment (Actual): 29
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Mexico
  • Oaxaca
    • Miahuatlán de Porfirio Díaz, Oaxaca, Mexico, 70805
      • Instituto Mexicano del Seguro Social - Unidad de Medicina Familiar 24, Miahuatlán de Porfirio Díaz, Oaxaca, México

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 60 years or older.
• Diagnosis of obesity (BMI ≥ 30 kg/m²).
• Patients attending the outpatient clinic of IMSS No. 24 in Miahuatlán de Porfirio Díaz, Oaxaca.
• Able to perform physical and functional tests (handgrip, SPPB).
• Capable of providing informed consent.
• Willing to comply with the intervention and attend baseline and 12-week evaluations.

Exclusion Criteria:

• Known diagnosis of hypercalcemia or disorders of calcium metabolism.
• Current use of high-dose vitamin D supplementation or medications affecting vitamin D metabolism.
• Severe renal or hepatic disease.
• Active cancer treatment.
• Neurological or musculoskeletal conditions that impair mobility or functional testing (e.g., recent fractures, severe osteoarthritis, stroke with major disability).
• Cognitive impairment preventing the understanding of instructions or informed consent.
• Any medical condition that, in the judgment of investigators, would interfere with participation or pose additional risk.
• Participation in another clinical trial during the study period.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vitamin D supplementation (Cholecalciferol); Participants receive oral vitamin D3 (cholecalciferol) at a dose of 10,000 IU per day for 12 weeks, in addition to their usual medical care. All participants undergo baseline and post-intervention assessments of muscle strength, muscle mass, functional performance, body composition, dietary intake, and serum 25(OH)D levels.	Dietary supplement: Vitamin D; Participants receive oral vitamin D3 (cholecalciferol) at a dose of 10,000 IU per day for 12 weeks, in addition to their usual medical care. All participants undergo baseline and post-intervention assessments of muscle strength, muscle mass, functional performance, body composition, dietary intake, and serum 25(OH)D levels.
Placebo Comparator: Placebo capsule; Daily oral placebo capsules for 12 weeks. Placebo capsules match the vitamin D capsules in size, shape, and appearance but contain inactive ingredients only.	Dietary supplement: Vitamin D placebo; Daily oral placebo capsules for 12 weeks. Placebo capsules match the vitamin D capsules in size, shape, and appearance but contain inactive ingredients only

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Handgrip strehgth (kg)	Muscle strength will be measured using a handheld dynamometer following standardized procedures. The highest value from two attempts per hand will be used. Results reported in kilograms (kg). Higher values indicate greater muscle strength.	Baseline and 12 weeks
Skeletal muscle mass	Skeletal Muscle mass assessed by Bioelectrical Impedance Analysis (BIA). Results reported in kilograms (kg)	Baseline and 12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body Fat percentage	Total body fat percentage measured using bioelectrical impedance analysis (BIA). The results will be expressed as a percentage (%)	Baseline and 12 weeks
Visceral Fat Index	Visceral fat index obtained through Bioelectrical Impedance Analysis (BIA). The results will be expressed in index units	Baseline and 12 weeks
Body Adiposity Index (BAI)	Body Adiposity Index calculated from hip circumference and height. The results will be expressed in index units	Baseline and 12 weeks
Short physical Performance Battery (SPPB) Score	Functional performance assessed using the SPPB, wich includes balance tests, gait speed, and chair stands.	Baseline and 12 weeks
Serum 25-Hydroxyvitamin D Levels	Serum levels of 25-hydroxyvitamin D [25(OH)D], measured in nanograms per mililiter (ng/mL)	Baseline and 12 weeks
SPPB Score	Short Physical Performance Battery (SPPB) score, ranging from 0 (worst performance) to 12 (best performance). Higher scores indicate better physical function.	Baseline and 12 weeks
Weight	Body weight measured in kilograms (kg)	baseline and 12 weeks
Body Mass Index (BMI)	Body Mass Index (BMI) calculated as weight (kg) divided by height squared (m2). The results will be expressed in kg/m2	Baseline and 12 weeks
Waist circumference	Waist circumference measured in centimeters (cm)	Baseline and 12 weeks
Metabolic Age	Metabolic Age estimated by BIA based on body composition paremeters. The results will be expressed in years	Baseline and 12 weeks

Collaborators and Investigators

• Sponsor: Universidad Autónoma Benito Juárez de Oaxaca
• Collaborators: National Council of Science and Technology, Mexico
• Investigators: Principal Investigator: Carlos Valencia Santiago, Doctor, Universidad Autónoma Benito Juárez de Oaxaca

Study record dates

Study Major Dates

• Study Start (Actual): January 9, 2024
• Primary Completion (Actual): November 9, 2024
• Study Completion (Actual): November 9, 2024

Study Registration Dates

• First Submitted: November 18, 2025
• First Submitted That Met QC Criteria: November 28, 2025
• First Posted (Actual): December 10, 2025

Study Record Updates

• Last Update Posted (Actual): December 10, 2025
• Last Update Submitted That Met QC Criteria: November 28, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Obesity; Older Adults; Aging; Sarcopenia; Vitamin D deficiency; Muscle Weakness; Sarcopenic Obesity; Functional Decline
• Additional Relevant MeSH Terms: Neurologic Manifestations; Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Manifestations; Pathologic Processes; Nutrition Disorders; Pathological Conditions, Anatomical; Overnutrition; Body Weight; Overweight; Muscular Atrophy; Atrophy; Avitaminosis; Deficiency Diseases; Malnutrition; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Muscle Weakness; Sarcopenia; Vitamin D Deficiency; Vitamin D Hydroxylation-Deficient Rickets, Type 1B; Polycyclic Compounds; Steroids; Fused-Ring Compounds; Secosteroids; Vitamin D
• Other Study ID Numbers: ESV/CIUU/290923

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because the study was conducted within a clinical care setting of IMSS and contains protected health information. Data are restricted by institutional and ethical 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