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Dietary Intake Modifications to Protect Against Changes in Bone Metabolism

Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism During Spaceflight and Recovery

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01713634
Acronym
ProK
Enrollment
17
Registered
2012-10-25
Start date
2009-01-31
Completion date
2015-11-30
Last updated
2015-11-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bone Resorption

Keywords

Bone resorption, Diet

Brief summary

Bone loss is not only a well-documented effect of spaceflight on astronauts, but also a condition that affects millions of men and women on Earth each year. Many countermeasures to bone loss have been proposed, and many have been evaluated to some degree. To date, those showing potential have focused on either exercise or pharmacological interventions, but none have targeted dietary intake alone as a factor to predict or minimize bone loss during spaceflight. The investigators proposed to document how the ratio of acid precursors to base precursors in the diet is related to directional changes in markers of bone resorption and formation during flight and recovery from flight. There is a high likelihood for success in predicting the extent of bone loss from dietary intake patterns of astronauts during spaceflight, given that this concept is strongly anchored in data obtained from ground-based experiments in our laboratory and others. The notion of manipulating diet to minimize bone loss could also have significant social and economic impacts for NASA and for the general public - especially given the increasing trends for diets that are high in animal protein and low in fruits and vegetables. The results of the proposed experiments will lead to development of a dietary countermeasure for bone loss consisting of a balanced diet with no associated risks for side effects that might be present with pharmaceuticals or supplements, no requirement for payload mass, and no additional crew time necessary during flight.

Interventions

OTHERPreflight

4-d controlled diet sessions will occur twice before flight.

OTHERIn-flight

4-d controlled diet sessions will take place on flight days 15, 60, 120, and 180. Flight day 30 will only be monitored intakes (subject consume nominal intake)

Sponsors

National Aeronautics and Space Administration (NASA)
Lead SponsorFED

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE

Eligibility

Sex/Gender
ALL
Healthy volunteers
Yes

Inclusion criteria

* Astronauts flying on long-duration (3-6 months) spaceflights

Exclusion criteria

* Non-astronauts

Design outcomes

Primary

MeasureTime frameDescription
Change in urinary calcium after 180 days of space flight compared to preflight180 days
Change in urinary n-telopeptide after 15 days of space flight compared to preflight15 days24-h NTX will be used as an indicator of bone resorption
Change in urinary n-telopeptide after 30 days of space flight compared to preflight30 days
Change in urinary n-telopeptide after 60 days of space flight compared to preflight60 days
Change in urinary n-telopeptide after 120 days of space flight compared to preflight120 days
Change in urinary n-telopeptide after 180 days of space flight compared to preflight180 days
Change in urinary calcium after 15 days of space flight compared to preflight15 days
Change in urinary calcium after 60 days of space flight compared to preflight60 days
Change in urinary calcium after 120 days of space flight compared to preflight120 days

Secondary

MeasureTime frameDescription
Change in urinary calcium after 30 days of space flight compared to preflight30 days24-h urinary calcium

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 6, 2026