Nutritional Status Assessment (Nutrition) - 09.17.14

Overview | Description | Applications | Operations | Results | Publications | Imagery
ISS Science for Everyone

Science Objectives for Everyone
Nutritional Status Assessment (Nutrition) is a comprehensive in-flight study designed to understand changes in human physiology during long-duration space flight. This study includes measures of bone metabolism, oxidative damage, and chemistry and hormonal changes; as well as assessments of the nutritional status of the crewmembers participating in the study. The results have an impact on the definition of nutritional requirements and development of food systems for future exploration missions to the Moon and Mars. This experiment also helps researchers understand the effectiveness of measures taken to counteract the effects of space flight, as well as the impact of exercise and pharmaceutical countermeasures on nutritional status and nutrient requirements for crewmembers.

Science Results for Everyone

What will astronauts eat on Mars? The Nutrition study seeks to answer this question, assessing the nutritional status of crew members and defining optimum nutritional requirements. Experiment design calls for the combination and comparative analysis of data from all Expeditions, so final results aren’t available yet. But preliminary results led to revised vitamin D supplementation recommendations and documented the effectiveness of the new dose. This experiment will also help researchers understand the effect of onboard exercise and pharmaceuticals on nutritional status and nutrient requirements for crewmembers.

The following content was provided by Scott M. Smith, Ph.D., and is maintained in a database by the ISS Program Science Office.

Experiment Details


Principal Investigator(s)

  • Scott M. Smith, Ph.D., NASA, Houston, TX, United States

  • Co-Investigator(s)/Collaborator(s)
  • Sara R. Zwart, Ph.D., Universities Space Research Association, Houston, TX, United States
  • Martina A. Heer, Ph.D., University of Bonn, Bonn, Germany
  • Stephen P. Coburn, Ph.D., Indiana University, University Purdue, IN, United States

  • Developer(s)
    Johnson Space Center, Human Research Program, Houston, TX, United States

    Sponsoring Space Agency
    National Aeronautics and Space Administration (NASA)

    Sponsoring Organization
    Human Exploration and Operations Mission Directorate (HEOMD)

    Research Benefits
    Information Pending

    ISS Expedition Duration
    September 2006 - September 2013

    Expeditions Assigned

    Previous ISS Missions
    A subset of this protocol, Clinical Nutritional Status Assessment Medical Requirement, has been performed on two Mir missions and on all ISS Expeditions.

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    Experiment Description

    Research Overview

    • This experiment is based on the ISS medical requirement for Clinical Nutritional Assessment (MedB.8.1). This includes collection of blood and urine samples before and after flight. Nutrition expands this protocol by capturing in-flight samples and extending the analyses to include additional biochemical measurements for samples from all sessions, including additional hormones, markers of bone metabolism and vitamin status; as well as tests for antioxidants and oxidative damage.

    • The results are used to better understand; a) the nutritional requirements for extended-duration space missions, b) the efficacy of countermeasures (such as exercise or pharmaceuticals), and c) the effect of countermeasures on nutritional status and nutrient requirements.

    Nutrition is critical for health both on Earth and on board the International Space Station. From the time the first crew lived on station up until now, the Clinical Nutritional Assessment profile is implemented to evaluate crew health before and after these 4- to 6-month missions. This clinical protocol nominally consists of two preflight and two postflight evaluations of nutritional status (largely through analysis of blood and urine samples), as well as an in-flight assessment of dietary intake using a Food Frequency Questionnaire. The Nutrition experiment sought to expand the medical requirement testing by including in-flight blood and urine collections and by expanding the nominal testing to include additional normative markers of nutritional assessment.
    Until 2006, it was not possible to conduct this type of study during ISS flights because blood and urine could not be collected, stowed frozen, and returned. The altered status of several nutrients after flight was worthy of concern, and alleviating that concern requires the ability to monitor the status of these nutrients during flight. This helps investigators determine if there is a specific impetus or timeframe for these decrements, which informs the requirements. In addition to allowing better monitoring of crew nutritional status during flight, in-flight sample collection allows better assessment of countermeasure effectiveness over the course of the mission, not just after flight.

    Additional markers of bone metabolism (e.g.,helical peptide, OPG, RANKL, IGF-1) are measured to better monitor bone health and countermeasure efficacy. New markers of oxidative damage are measured (8-iso-prostaglandin F2α, protein carbonyls, oxidized and reduced glutathione) to better assess the type of oxidative insults that occur during space flight. The array of nutritional assessment variables expanded to include serum folate, plasma pyridoxal 5'-phosphate, vitamin D binding protein, and homocysteine to better understand changes in folate, vitamin B6, and vitamin D status, and related cardiovascular risk factors; respectively, during and after flight. Additionally, stress hormones and hormones that affect bone and muscle metabolism (DHEA, DHEA-S, cortisol, C-reactive protein, testosterone, estradiol) will be measured. This additional assessment provides better health monitoring and allows more accurate recommendations for crew rehabilitation to be made. These variables were added to follow the recommendations of an extramural panel that met to define nutritional standards and requirements in 2005.

    The protocol comprises these steps:

    • Collection of blood and urine samples before, during and after flight

    • Biochemical analysis of these samples, in large part at the Johnson Space Center, using standard laboratory methods

    • Statistical analysis of the analytical results to detect differences in nutritional status at different times.

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    Space Applications
    The inclusion of in-flight blood and urine collections, and expansion to include additional variables to better monitor nutritional status, are required in order to better understand the role of nutrition in bone health, changes in body composition, oxidative damage, and to better define nutritional requirements for space flight. Maintaining and monitoring nutritional status is important for ensuring crew health during space flight, and is critical as we embark on exploration missions of longer duration in the future.

    Earth Applications
    Increased understanding of the role of nutrition in physiological adaptation to space flight has a broader application on Earth. One example is that understanding the relationship of nutrition to bone loss is potentially valuable for patients suffering from bone loss on Earth.

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    Operational Requirements
    Sample sessions occur on Flight Days 15 ( 5 days), 30, 60, 120, and 180 ( 14 days). Samples are returned to Earth for analysis within a year of the sampling date.

    Operational Protocols
    During flight, the crew collects blood and 24-h urine samples on the five days designated. The blood samples are processed in the refrigerated centrifuge and then stored in the MELFI. Urine is collected void by void for 24 hours and syringe aliquot samples are stored in the MELFI.

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    Results/More Information

    This experiment is still ongoing; urine and blood samples for several astronauts have been collected before, during and after ISS Expeditions. Since the experiment design calls for the combination and comparative analysis of data from all Expeditions, final results are not yet available. Preliminary results have been presented, reviewed, and published in multiple forums(Evans et al. 2009) . Operationally, the data have been valuable in troubleshooting the Urine Processing Assembly (UPA) after the unit developed problems on orbit in 2009, and also in developing operational plans for using this unit. Vitamin D results from spaceflight and ground-based analog studies led to revised vitamin D supplementation recommendations on ISS, and the results of this experiment have documented the effectiveness of this new dose. The ground-based findings from Antarctic research were cited in the Institute of Medicine’s revision of the recommended dietary intakes for North Americans.

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    Results Publications

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    Ground Based Results Publications

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    ISS Patents

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    Related Publications

      Zwart SR, Kala G, Smith SM, Smith SM.  Body iron stores and oxidative damage increased after a 10- to 12-day undersea dive in humans. Journal of Nutrition. 2009; 139: 90-95.

      Smith SM, Smith SM, Zwart SR, Kloeris VA, Heer MA, Heer MA, Heer MA.  Nutritional Biochemistry of Space Flight.. Happauge, NY: Nutritional Biochemistry of Space Flight; 2009.

      Zwart SR, Pierson DL, Mehta SK, Gonda S, Smith SM, Smith SM.  Capacity of Omega-3 Fatty Acids or Eicosapentaenoic Acid to Counteract Weightlessness-Induced Bone Loss by Inhibiting NF-ºB Activation: From Cells to Bed Rest to Astronauts. Journal of Bone and Mineral Research. 2009; 0.

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    Related Websites
    Human Adaptation and Countermeasures Division

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    image The Nutrition blood and urine collection kits for in-flight sample collection on board ISS. Image courtesy of NASA Johnson Space Center.
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    image NASA Image: ISS033E018812 - Astronaut Sunita Williams,Expedition 33 Commander,is photographed during a blood draw in the Columbus module.
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    image Screenshot of ISS Expedition 14 Commander Michael Lopez-Alegria preparing the centrifuge for the blood samples taken for the Nutrition investigation. The blood sample can be seen in the test tube at the lower left of the image.
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    image NASA Image: ISS030E293906 -
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    image NASA Image ISS014E05124 - Expedition 14 Commander and NASA Astronaut Michael Lopez-Alegria inserts blood and urine samples into the Minus Eighty Degree Laboratory Freezer for ISS (MELFI) until they can be returned to Earth for analysis
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    image Screenshot of ISS Expedition 14 Commander Michael Lopez-Alegria labeling a urine collection syringe (lower right of image) that will be used to remove urine from the Urine Collection Device (UCD), floating in the foreground of the image.
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    image NASA Image ISS014E13963 - Astronaut Suni Williams, Expedition 14 Flight Engineer, prepares a laptop in the Human Research Facility-2 (HRF-2) for data entry during a blood draw as part of the Nutritional Status Assessment (Nutrition) study in the Destiny laboratory module.
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    image NASA Image ISS014E17530 - Astronaut Michael Lopez-Alegria, Expedition 14 Commander, prepares a urine sample for the Nutrition investigation. The sample is preserved in the Minus Eighty Degree Freezer ISS (MELFI) in the Destiny laboratory module.
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    image NASA Image ISS015E10554 - Astronaut Sunita L. Williams, Expedition 15 Flight Engineer, loads test samples in the Human Research Facility 2 (HRF-2) Refrigerated Centrifuge as a part of the Nutritional Status Assessment (Nutrition) experiment. The results of the Nutrition experiment will be used to better understand the time course of the effects of space flight on human physiology.
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    image NASA Image ISS020E007156 - Canadian Space Agency astronaut Robert Thirsk, Expedition 20 flight engineer, performs an insertion of urine samples into the Minus Eighty Degree Laboratory Freezer for ISS (MELFI) as part of the Nutritional Status Assessment (NUTRITION) study in the Japanese Kibo laboratory of the International Space Station.
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    image NASA Image: Nutrition
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    image NASA Image: ISS032E009066
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