ClinicalTrials.gg
RecruitingNCT05174611Updated Mar 18, 2025

Vitamin D to Improve Quadricep Muscle Strength

A Phase 2 interventional study of Vitamin D3 and Placebo in Anterior Cruciate Ligament Injuries, Quadriceps Muscle Atrophy and Anterior Cruciate Ligament Rupture, sponsored by Chinese University of Hong Kong. Recruiting at 1 site in Hong Kong. Open to participants aged 18 Years to 40 Years. Per ClinicalTrials.gov, last updated 2025-03-18.

Sponsored by Chinese University of Hong Kong · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Mar 2025; still recruiting 1 year 7 months later.
Phase
Phase 2
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
18 Years to 40 Years
Sex
All
01

Where this study stands

Counted across the records on this site · 2026-11-12

Among 10 studies in Anterior Cruciate Ligament Injuries by Chinese University of Hong Kong — 4 open to participants now, 5 under way, none of them phase 3. Anterior Cruciate Ligament Injuries · Chinese University of Hong Kong.

Started
2025
the only one that year
Phase 2
Only one
of the 10
Registered
6th of 10
by date

Among the 10 studies in Anterior Cruciate Ligament Injuries by Chinese University of Hong Kong, this one is the only one that started in 2025, is the only one in phase 2, and was the 6th registered.

Anterior Cruciate Ligament Injuries

625 studies on the registry are indexed under Anterior Cruciate Ligament Injuries; 192 are open to participants now.

Browse Anterior Cruciate Ligament Injuries studies →

Open to participants now

4 of the 10 studies in Anterior Cruciate Ligament Injuries by Chinese University of Hong Kong are open now, in 1 country. Recruiting first, the newest first:

By country, each count listing its studies:

All 4 open studies →

Where they have run

Who these studies take

Of the 121 Anterior Cruciate Ligament Injuries studies recruiting now, 27 (22%) set no upper age limit and 91 (75%) stop at 75 or younger; 46 take children under 18; 21 take healthy volunteers.

This study: 18 Years to 40 Years · all sexes · no healthy volunteers.

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02

Study summary

Quadriceps muscle strength is one of the key determinants for patients to fulfill the Return-to-Play (RTP) criteria after an anterior cruciate ligament reconstruction (ACLR), in which the muscle size is directly linked to muscle strength. Quadriceps muscle atrophy is unavoidable after ACLR, but the rehabilitation program should increase quadriceps muscle mass. However, despite good rehabilitation compliance, some patient's progress is sub-par and fail to regain muscle mass. Quadriceps muscle atrophy can persist beyond the completion of the rehabilitation program in almost half the patients and the reason behind this is still unknown. This represents an area that requires significant investigation, as quadriceps muscle atrophy and weakness have been shown to be determinants of poor knee function, decreased performance in sports and increased risk of reinjury.

Quadriceps muscle atrophy after ACLR is well documented. This can be due to a decreased ability to regain muscle mass with rehabilitation. Athletes are one of the high-risk groups for vitamin D insufficiencies. Vitamin D deficiency can potentially result in decreased hypertrophy when exercising the muscle, leading to a poorer outcome in rehabilitation. Vitamin D has long been recognized for its effect on musculoskeletal health. It can have a direct effect on muscle hypertrophy by acting on specific vitamin D receptors (VDRs) on myocytes, and sufficient or increased levels of vitamin D in patients have been found to correlate with an increase in the size, number, and strength of muscle fibres. Quadriceps muscle hypertrophy after ACLR is triggered by exercise training, facilitated by diet and a number of intrinsic factors. As the rehabilitation programs and diets are similar in patients with varying extents of quadriceps muscle atrophy, individual responses (intrinsic factors) to exercise training may account for the resulting persistent quadriceps muscle atrophy. In this study, the investigators hypothesize that the deficiency of vitamin D may contribute to persistent quadriceps atrophy and weakness.

With a stringent double-blinded randomized-controlled-trial (RCT) research design, our proposal will then address the research questions: 'Does vitamin D supplements improve the vitamin D deficiency status in patients after ACL reconstruction?', and 'Does vitamin D supplements improve quadriceps muscle strength for patients after ACLR?'

03

Conditions studied

  • Anterior Cruciate Ligament Injuries
  • Quadriceps Muscle Atrophy
  • Anterior Cruciate Ligament Rupture
  • Anterior Cruciate Ligament Tear

Keywords

  • ACL Reconstruction
  • Vitamin D
  • Quadricep muscle strength
  • Quadricep muscle atrophy
04

Who can participate

Ages eligible
18 Years to 40 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Aged 18-40 with unilateral ACL injury
  2. Sporting injury with a Tegner score of 7
  3. Pre-op serum vitamin D level \<20 ng/ml
  4. 4 months post-ACLR with serum Vitamin D level remained \<20ng/ml
  5. LSI for quadriceps strength \<70% of contralateral leg at 4-month isokinetic assessment
  6. Both knees without history of injury/prior surgery

Exclusion criteria

Exclusion Criteria:

  1. Concomitant bone fracture, major meniscus injury or full-thickness chondral injuries requiring altered rehabilitation program post-operatively
  2. Pre-operative radiographic signs of arthritis
  3. Metal implants that would cause interference on MRI
  4. Non-HS graft for ACLR
  5. Patient non-compliant to the rehabilitation program
  6. Regular sunbed users
05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Care provider)
Enrollment
60 participants (estimated)

Study arms

  • Experimental
    Treatment group

    Subject in treatment group will receive one capsule of 2000IU Vitamin D3 supplement per day with the duration of 16 weeks.

    Dietary Supplement: Vitamin D3

  • Placebo comparator
    Placebo group

    Subject in placebo group will receive one capsule of placebo per day which looks exactly same as the Vitamin D3 capsule with the duration of 16 weeks.

    Other: Placebo

Interventions

  • Dietary supplementVitamin D3

    Subjects will receive 112 capsules with 4 bottles, 28 capsules in each bottle.

  • OtherPlacebo

    Subjects will receive 112 capsules with 4 bottles, 28 capsules in each bottle.

06

What researchers measure

Primary outcomes

  1. Change of Isokinetic muscle strength

    The dynamometer (Biodex System 4, Biodex Medical Systems Inc., New York, USA) will be used for measuring Isokinetic muscle strength in N. Subjects will perform a standardized warm-up exercise (5 min cycling) followed by the test. Concentric/concentric contractions of knee extension/flexion will be tested at 60°/s and 180°/s. Subjects will be seated on the dynamometer chair with their hips flexed to 85°.

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

  2. Change of Biochemical Assays

    Blood samples will be taken under non-fasting conditions. Serum / plasma obtained will be immediately stored at -80°C until analysis. Serum 25(OH) Vit-D assay: Serum 25(OH)Vit-D levels will be measured by commercial 25(OH) Vitamin D ELISA kit (Abcam ab213966) according to the manufacturer's instruction, providing the quantitative determination of 25(OH) Vitamin D3 and 25(OH) Vitamin D2. Sensitivity: 1.98 ng/ml (Range: 0.5 ng/ml - 1010 ng/ml).

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

Secondary outcomes

  1. MRI Muscle thickness

    Muscle volumes of quadricep muscle are measured using a 1.5 or 3.0 Tesla MRI Scanner. Axial (3mm thick cut) T1W images are obtained from the anterior superior iliac supine (ASIS) to patella. Quadriceps muscles were manually outlined in each axial slice. Muscle volume was calculated by summing all of the slice-multiplied by slice thickness. The quality of the muscle is assessed by analyzing the fat content of the muscle mass using technique that has been reported by Reeder et al (6). Bilateral legs will be performed before the start of the vitamin supplementation (4 months post-op) and with the injured side repeated after the completion of the 16-weeks supplementation (8 months postop).The uninjured side will be used as reference for 'normal volume'.

    Time frame: 4- & 8- months post operation

  2. Ultrasound imaging muscle thickness

    The Aixplorer® ultrasound system and a linear transducer probe with a bandwidth of 2-10 MHz were used to measure the muscle thickness of Vastus Medialis (VM), Vastus Lateralis (VL), and Rectus Femoris (RF) on both the injured and uninjured leg. Participants laid supine on a treatment table for the assessment. A measuring tape was used to locate VM, VL, RF and the patella by palpation, consequently marked with a pen for reference. RF was marked at 1/2 of the distance from the anterior superior iliac spine (ASIS) to the superior pole of the patella, VM was located at 1/5 of the distance away from the midpoint of the medial patella border to the ASIS, and VL was noted at 1/3 of the distance from the midpoint of the lateral patella border to the ASIS. After locating the anatomical points, excess contact gel was applied on these points. The transducer probe was aligned in the transverse plane and moved along the entire muscle bundle to capture a view of the VM, VL and RF.

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

  3. Passive Knee laxity

    To measure anterior-posterior knee laxity, the KT-1000 knee ligament arthrometer (MEDmetric Corp, San Diego, CA, USA) will be used. A manual force test will be applied until a 30lb sound signal is activated. Three trials will be performed. A side difference of 3 mm above is considered clinically relevant.

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

  4. Change of BMI Anthropometric Measurement

    Body Mass Index (BMI) in kg/m\^2 would be calculated by the measured height and weight at 4 months post ACLR before vitamin D supplements, during the eighth week of vitamin D supplements, after the completion of 16 weeks vitamin D supplements, and 12-months post-operation.

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

  5. Ground reaction force

    The Kinetic variables including vertical and horizontal ground reaction force (GRF) will be evaluated by a synchronized force plate at the centre of the capture volume at 1000Hz.

    Time frame: pre PEMF treatment , 4weeks, 8 weeks and 8 months after the commencement of intervention

  6. Knee Joint moments

    The kinematics will be assessed by the skin marker-based motion analysis system with the lower-body marker setup followed the OSTRC standard using 16-camera and 16 reflective skin marker during the single leg squat and single leg hop test.

    Time frame: pre PEMF treatment , 4weeks, 8 weeks and 8 months after the commencement of intervention

  7. Single leg hop distance

    The average of single leg hop distance in cm with three attempts will be measured during the single leg hop test.

    Time frame: 4weeks, 8 weeks and 8 months after the commencement of intervention

  8. Visual Analogue Scale

    The subjective measurement for chronic and acute pain will be recorded by the Visual Analogue Scale (VAS). VAS consists of a 10-cm line which represents the continuum between "painless" and "worst pain from 0 cm to 10 cm. The subject will be asked to draw a mark of it before and after each PEMF treatment session.

    Time frame: Before and immediate after 1st - 16th of PEMF treatment

  9. Tegner activity score

    This is an activity level scaled from 1 (low activity) to 10 (high activity).

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

  10. International Knee Documentation Committee

    Consists of 10 questions on symptoms and activity ranging from 0 to 100 where 100 implies perfect knee function.

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

  11. Lysholm knee scoring system

    Consists of eight items, total score ranging from 0 to 100 where higher scores indicate a better outcome with fewer symptoms or disability.

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

  12. International Physical Activity Questionnaire

    The level of physical activities during the past 7 days will be evaluated with a validated Chinese version of the quantitative physical activity questionnaire.

    Time frame: Pre operation, 4-, 6- 8- and 12months post operation

07

Study locations

1 of 1 sites recruiting
08

References and documents

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: Yes — All IPD that underlie results in a publication

Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code

Time frame: starting 6 months after publication

Access criteria: Journal reviewers

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started Mar 2025 (actual). Primary completion is estimated for Mar 2028, 36 months after the start.

How these figures are worked out, and which studies are left out of them.

Registered
Nov 28, 2021
First posted
Jan 3, 2022
StartActual
Mar 17, 2025
Primary completionEst.
Mar 17, 2028
CompletionEst.
Sep 17, 2029
Last update
Mar 18, 2025
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Mar 18, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05174611
Responsible party
Prof. Tim-Yun Michael ONG (Clinical Assistant Professor, Chinese University of Hong Kong) — Principal investigator
First posted
Jan 3, 2022
Start date
Mar 17, 2025
Primary completion
Mar 17, 2028 (estimated)
Completion
Sep 17, 2029 (estimated)
Last update
Mar 18, 2025

Study contacts

Michael Tim-Yun Ong
Contact
michael.ong@cuhk.edu.hk
26364171

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drug tested here: Cholecalciferol

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