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Stable Calcium Isotopes in Urine as a Biomarker of Bone Mineral Balance in Spaceflight (NNX14AB78G)
Principal Investigator
Research Area:
Skeletal physiology
Species Studied
Scientific Name: Homo sapiens Species: Human

Long duration human space flight leads to loss of bone mass. As a consequence, there is a need for techniques to sensitively detect changes in the net rate of bone formation or resorption (i.e. change in "bone mineral balance") and to assess the effectiveness of countermeasures. It has been documented in bed rest experiments that measurements of the calcium (Ca) isotope composition of urine using mass spectrometry can be used to monitor rapid changes in net bone mineral balance that are not directly observable by other means. This could be extended to the International Space Station (ISS), in order to demonstrate the utility of Ca isotopes as a tool for monitoring bone mineral balance and countermeasures to bone resorption in space. This proposal built on a successful existing collaboration between researchers at Arizona State University and NASA Johnson Space Center to study and apply the Ca isotope method as a bone biomarker. The proposed project paved the way for future development of capability to measure Ca isotopes in-flight to monitor bone health during exploration-class space missions where in situ evaluation of the effectiveness of countermeasures was required to assure crew health and safety.

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Gordon GW, Monge J, Channon MB, Wu Q, Skulan JL, Anbar AD, Fonseca R. ''Predicting multiple myeloma disease activity by analyzing natural calcium isotopic composition." Leukemia. 2014 Oct;28(10):2112-5. Epub 2014 Jun 12. [DOI]

Channon MB, Gordon GW, Morgan JL, Skulan JL, Smith SM, Anbar AD. "Using natural, stable calcium isotopes of human blood to detect and monitor changes in bone mineral balance." Bone. 2015 Aug;77:69-74. Epub 2015 Apr 18. [DOI]

Romaniello SJ, Field MP, Smith HB, Gordon GW, Kim MH, Anbar AD. "Fully automated chromatographic purification of Sr and Ca for isotopic analysis." Journal of Analytical Atomic Spectrometry 2015;9:1906-12. [DOI]

Gordon GW, Monge J, Channon MB, Wu Q, Skulan J, Anbar AD, Fonseca R. "Calcium isotopic composition and its association with multiple myeloma disease activity." Presented at 55th American Society of Hematology (ASH) Annual Meeting and Exposition, New Orleans, LA, Dec. 7-10, 2013.

Smith HB, Kim H, Romaniello SJ, Field P, Anbar AD. "A robust and fullyautomated chromatographic method for the quantitative purification of Ca and Sr for isotopic analysis." Presented at the Fall Meeting 2014, American Geophysical Union, San Francisco, CA, Dec 15-19 2014.

Anbar A, Gordon G, Skulan J, Smith S, Fonseca R. "Developing a clinically useful calcium isotope biomarker." 25th V. M. Goldschmidt Conference, Prague, Czech Republic, August 16-21, 2015.

Skulan JL, Gordon GW, Anbar AD, Zwart S, Smith SM. "Bone Mineral Balance in Astronaut Urine Before, During and After Spaceflight as Inferred from Ca Isotope Variations." 2015 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 13-15, 2015.

Gordon GW, Romaniello SR, Skulan JL, Smith SM, Zwart S, Anbar AD. "Stable Calcium Isotopes in Urine as a Biomarker of Bone Mineral Balance in Spaceflight." 2016 NASA Human Research Program Investigators’ Workshop, Galveston, TX, February 8-11, 2016.

Gordon GW, Romaniello SR, Skulan JL, Smith SM, Zwart S, Zheng W, Letcher AJ, Anbar, AD. "Natural calcium isotopes provide rapid and precise monitoring of bone mineral balance changes in microgravity." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

Skulan J, Smith S, Anbar AD, Gordon GW, Romaniello SJ, Zwart S. "Calcium isotopes measure change in bone mineral balance during spaceflight." Presented at the 22017 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 23-26, 2017.

Gordon GW, Romaniello SJ, Skulan JL, Smith SM, Zwart S, Letcher A, Anbar AD. "Monitoring bone mineral balance in spaceflight using natural calcium isotopes in astronaut urine." Presented at the 12th International Symposium on Applied Isotope Geochemistry (AIG-12), Copper Mountain, Colorado, September 17-22, 2017.

Bone resorption
Biological markers

Data Information
Data Availability
Archive is complete. Data sets are not publicly available but can be requested.
Data Sets+ Request data

Bone loss
Bone mineral balance changes
Isotopic shift, magnitude
Isotopic shift, time
Natural calcium isotope, urine

Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Ground 05/01/2009 In Progress

Human Research Program (HRP) Human Research Roadmap (HRR) Information
Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and performance, providing essential countermeasures and technologies for human space exploration. Risks include physiological and performance effects from hazards such as radiation, altered gravity, and hostile environments, as well as unique challenges in medical support, human factors, and behavioral health support. The HRP utilizes an Integrated Research Plan (IRP) to identify the approach and research activities planned to address these risks, which are assigned to specific Elements within the program. The Human Research Roadmap is the web-based tool for communicating the IRP content.

The Human Research Roadmap is located at:

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Additional Information
Other Key People
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Institutional Support
National Aeronautics and Space Administration (NASA)
Proposal Date
Proposal Source
2012 Crew Health NNJ12ZSA
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