The effect of calcium supplementation on calcium and bone metabolism during load carriage in women: protocol for a randomised controlled crossover trial.
Study Goal
The researchers aimed to determine whether calcium supplementation (1000 mg) could protect bone and calcium homeostasis during load carriage exercise in women.
Results Summary
The study is ongoing, so no results are reported yet. The abstract describes the methodology but does not provide findings on calcium's effects.
Population
Thirty women (eumenorrheic or using combined oral contraceptive pill, intrauterine system, or intrauterine device).
Effective Dosage
1000 mg calcium supplement (single dose before exercise).
Duration
One 120-minute session of load carriage exercise per testing session.
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
Exercise | decrease | circulating serum calcium | - | - | decrease | #1 |
Exercise | increase | parathyroid hormone | - | - | increase | #2 |
Exercise | increase | bone resorption | - | - | increase | #3 |
calcium supplementation immediately before exercise | decrease | disturbances to calcium and bone metabolism | - | - | attenuated | #4 |
calcium supplementation | neutral | calcium and bone metabolism, and bone mineral balance | women | - | effect | #5 |
calcium supplement (1000 mg) | neutral | bone and calcium homeostasis | women | - | protective | #6 |
BACKGROUND: Military field exercises are characterised by high volumes of exercise and prolonged periods of load carriage. Exercise can decrease circulating serum calcium and increase parathyroid hormone and bone resorption. These disturbances to calcium and bone metabolism can be attenuated with calcium supplementation immediately before exercise. This randomised crossover trial will investigate the effect of calcium supplementation on calcium and bone metabolism, and bone mineral balance, during load carriage exercise in women. METHODS: Thirty women (eumenorrheic or using the combined oral contraceptive pill, intrauterine system, or intrauterine device) will complete two experimental testing sessions either with, or without, a calcium supplement (1000 mg). Each experimental testing session will involve one 120 min session of load carriage exercise carrying 20 kg. Venous blood samples will be taken and analysed for biochemical markers of bone resorption and formation, calcium metabolism, and endocrine function. Urine will be collected pre- and post-load carriage to measure calcium isotopes for the calculation of bone calcium balance. DISCUSSION: The results from this study will help identify whether supplementing women with calcium during load carriage is protective of bone and calcium homeostasis. TRIAL REGISTRATION: NCT04823156 (clinicaltrials.gov).