NCT04823156

Brief Summary

This randomised trial will investigate the effect of calcium supplementation on bone and calcium metabolism in women during acute load carriage exercise. This study will test the hypothesis that calcium supplementation before load carriage exercise will attenuate the decline in serum ionised calcium and increase in parathyroid hormone and bone resorption.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
40

participants targeted

Target at P25-P50 for not_applicable

Timeline
Completed

Started Mar 2022

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

July 7, 2020

Completed
9 months until next milestone

First Posted

Study publicly available on registry

March 30, 2021

Completed
12 months until next milestone

Study Start

First participant enrolled

March 24, 2022

Completed
1.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 19, 2023

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

May 19, 2023

Completed
Last Updated

April 21, 2023

Status Verified

April 1, 2023

Enrollment Period

1.2 years

First QC Date

July 7, 2020

Last Update Submit

April 20, 2023

Conditions

Keywords

MilitaryStress FractureCalciumBone Metabolism

Outcome Measures

Primary Outcomes (1)

  • Change in calcium balance.

    The ratio of the calcium isotopes Ca44:Ca42 in spot urine samples.

    Before and immediately after exercise.

Secondary Outcomes (4)

  • Circulating calcium isotopes during load carriage.

    Before and immediately after exercise.

  • Bone turnover during load carriage.

    0, 20, 40, 60, 80, 100, and 120 minutes during, and 15, 30, 60 and 90 minutes following, exercise.

  • Calcium metabolism during load carriage.

    0, 20, 40, 60, 80, 100, and 120 minutes during, and 15, 30, 60 and 90 minutes following, exercise.

  • Dermal calcium loss.

    During exercise.

Other Outcomes (1)

  • Change in muscle strength during load carriage.

    Before and immediately after exercise.

Study Arms (2)

Calcium Supplementation

EXPERIMENTAL

1000 mg of calcium carbonate one hour before exercise

Dietary Supplement: Calcium

No Calcium Supplementation

NO INTERVENTION

No calcium supplementation

Interventions

CalciumDIETARY_SUPPLEMENT

Daily calcium food supplement.

Calcium Supplementation

Eligibility Criteria

Age18 Years - 36 Years
Sexfemale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Female sex;
  • Aged 18 to 36 years old;
  • Maximal rate of oxygen uptake of ≥ 35 ml∙kg-1∙min-1;
  • Weight stable (no change in self-reported body mass ≥ 5% over the previous 3 months);
  • BMI between 18 and 30 kg∙m2;
  • Not pregnant.

You may not qualify if:

  • Evidence of disordered eating (≥ 20 on the EAT-26);
  • Self-reported change in body mass of ≥ 5% over the previous 3 months;
  • Vitamin D deficient (total 25(OH)D \< 30 nmol∙L-1);
  • Maximal rate of oxygen uptake of \< 35 ml∙kg-1∙min-1;
  • Total body BMD T-score of \< -1;
  • Evidence of menstrual disturbance (oligomenorrhoea: \< 9 menstrual cycles in previous 12 months or amenorrhoea: ≤ 3 menstrual cycles in the previous 12 months);
  • Pregnant;
  • Current smoker, or stopped smoking within the last three months;
  • Taking any medications known to affect bone or calcium metabolism (e.g. treatment for thyroid disorders);
  • Self-declared history of heart, liver or kidney disease, diabetes or thyroid disorder;
  • Self-reported stress fracture or any other bone injuries in the previous 12 months;
  • Anaemia (haemoglobin \<12 g∙/dL-1).
  • Currently using the implant, injection, or the progesterone-only pill ('mini pill').

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Army Health and Performance Laboratory

Camberley, Surry, GU15 4PQ, United Kingdom

RECRUITING

Related Publications (2)

  • Coombs CV, Greeves JP, Young CD, Irving AS, Eisenhauer A, Kolevica A, Heuser A, Tang JCY, Fraser WD, O'Leary TJ. The effect of calcium supplementation on bone calcium balance and calcium and bone metabolism during load carriage in women: a randomized controlled crossover trial. J Bone Miner Res. 2025 Jun 3;40(6):753-765. doi: 10.1093/jbmr/zjaf004.

  • Coombs CV, Wardle SL, Shroff R, Eisenhauer A, Tang JCY, Fraser WD, Greeves JP, O'Leary TJ. The effect of calcium supplementation on calcium and bone metabolism during load carriage in women: protocol for a randomised controlled crossover trial. BMC Musculoskelet Disord. 2023 Jun 16;24(1):496. doi: 10.1186/s12891-023-06600-w.

MeSH Terms

Conditions

Fractures, Stress

Interventions

Calcium

Condition Hierarchy (Ancestors)

Fractures, BoneWounds and Injuries

Intervention Hierarchy (Ancestors)

Metals, Alkaline EarthElementsInorganic ChemicalsMetalsBlood Coagulation FactorsBiological Factors

Central Study Contacts

Thomas J O'Leary, PhD

CONTACT

Charlotte V Coombs, PhD

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Masking Details
Calcium supplements will be provided open-label.
Purpose
PREVENTION
Intervention Model
CROSSOVER
Model Details: Crossover randomised controlled trial.
Sponsor Type
OTHER GOV
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Higher Scientific Officer

Study Record Dates

First Submitted

July 7, 2020

First Posted

March 30, 2021

Study Start

March 24, 2022

Primary Completion

May 19, 2023

Study Completion

May 19, 2023

Last Updated

April 21, 2023

Record last verified: 2023-04

Data Sharing

IPD Sharing
Will not share

Data will be owned by UK Ministry of Defence, not the Principal Investigator. Data will be made available where possible by the Principal Investigator assuming the appropriate approvals are granted by the UK Ministry of Defence.

Locations