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Cited by 316Spaceflight effects on biologySpace Exploration and TechnologySpace exploration and regulation

The Nutritional Status of Astronauts Is Altered after Long-Term Space Flight Aboard the International Space Station

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Smith, Scott M., Zwart, Sara R., Block, Gladys, Rice, Barbara L., Davis-Street, Janis E.·2005·The Journal of Nutrition
DOI 10.1093/jn/135.3.437
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Abstract

Defining optimal nutrient requirements is critical for ensuring crew health during long-duration space exploration missions. Data pertaining to such nutrient requirements are extremely limited. The primary goal of this study was to better understand nutritional changes that occur during long-duration space flight. We examined body composition, bone metabolism, hematology, general blood chemistry, and blood levels of selected vitamins and minerals in 11 astronauts before and after long-duration (128-195 d) space flight aboard the International Space Station. Dietary intake and limited biochemical measures were assessed during flight. Crew members consumed a mean of 80% of their recommended energy intake, and on landing day their body weight was less (P = 0.051) than before flight. Hematocrit, serum iron, ferritin saturation, and transferrin were decreased and serum ferritin was increased after flight (P < 0.05). The finding that other acute-phase proteins were unchanged after flight suggests that the changes in iron metabolism are not likely to be solely a result of an inflammatory response. Urinary 8-hydroxy-2'-deoxyguanosine concentration was greater and RBC superoxide dismutase was less after flight (P < 0.05), indicating increased oxidative damage. Despite vitamin D supplement use during flight, serum 25-hydroxycholecalciferol was decreased after flight (P < 0.01). Bone resorption was increased after flight, as indicated by several markers. Bone formation, assessed by several markers, did not consistently rise 1 d after landing. These data provide evidence that bone loss, compromised vitamin D status, and oxidative damage are among critical nutritional concerns for long-duration space travelers.

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  • Astronauts had a decrease in 1,25 vitamin D levels, consistent with other studies.

    “Astronauts had a decrease in 1,25 vitamin D levels (the active form of vitamin D) (Fig. 5B) consistent with other studies (Smith et al., 2005)”

    From Comprehensive Multi-omics Analysis Reveals Mitochondrial Stress as a Central Biological Hub for Spaceflight Impact (2020) · cites this paper as Smith et al., 2005

    The Bone markers section says that 1,25-dihydroxycholecalciferol, the active form of vitamin D, was not different after landing. It was 25-hydroxycholecalciferol—a different measure—that decreased; the paper describes similar findings in earlier studies for that measure. (LLM, conf=0.93)

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  • Serum retinol significantly differs between pre- and post-flight samples but not during flight; it decreased from 0.73 ± 0.17 to 0.59 ± 0.13 μg/mL on landings in Russia and increased from 0.52 ± 0.09 to 0.63 ± 0.12 μg/mL on landings in the US.

    “In addition, there is a significant difference of serum level retinol between pre- and post-flight samples but not during flight. Serum retinol decreased from 0.73 ± 0.17 to 0.59 ± 0.13 µg/mL on landings occurred in Russia and increased from 0.52 ± 0.09 to 0.63 ± 0.12 µg/mL on landings in the US48,142.”

    From Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions (2021) · cites this paper as [48]

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  • Initial findings from Clinical Nutritional Assessment identified evidence of vitamin D deficiency, altered folate status, loss of body mass, increased kidney stone risk, and more.

    “Initial findings from the Clinical Nutritional Assessment protocol identified evidence of vitamin D deficiency, altered folate status, loss of body mass, increased kidney stone risk, and more69,70.”

    From Red risks for a journey to the red planet: The highest priority human health risks for a mission to Mars (2020) · cites this paper as [69]

    The Discussion reports a roughly 20% decrease in RBC folate and lower vitamin D status after flight; the Body composition section reports about 5% lower body weight on landing day (P = 0.051). The paper describes vitamin D status as compromised or suboptimal, rather than establishing frank deficiency. It also calls decreased urinary magnesium a possible concern for renal stones, rather than demonstrating an increased kidney-stone risk. (LLM, conf=0.85)

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  • Astronauts from ISS expeditions 1-8 had elevated urine 8OHdG by 32% upon landing on Earth, despite no evidence of lipid peroxidation.

    “astronauts from the ISS expeditions 1–8 were tested for oxidative stress upon landing, and researchers found that urine concentration of 8-hydroxy-2′-deoxyguanosine (8OHdG) was elevated by 32% upon landing on Earth, despite no evidence of lipid peroxidation”

    From Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions (2021) · cites this paper as [48]

  • Red blood count SOD was found to be reduced in astronauts, suggesting a decreased antioxidant capacity.

    “Additionally, astronauts were also tested for red blood count SOD that was found to be reduced, thus suggesting a decreased antioxidant capacity48.”

    From Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions (2021) · cites this paper as [48]

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4 of the 51 references couldn’t be matched to a known paper.

Research works printed but not linked: 3

  1. [15]15. Lippincott Williams & Wilkins, Baltimore, MD.
  2. [20]20. Institute of Medicine (1997) Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. National Academies Press, Washington, DC.
  3. [21]21. National Research Council (2000) Dietary Reference Intakes for Cal- cium, Phosphorus, Magnesium, Vitamin D, and Fluoride. The National Academy Press, Washington, DC.

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Authors
Smith, S. M., Zwart, S. R., Block, G., Rice, B. L., & Davis-Street, J. E.
Affiliations
  • National Aeronautics and Space Administration (US)
  • University of California, Berkeley (US)
Corresponding author
Smith, Scott M.
ORCID
Venue
The Journal of Nutrition
Publisher
Elsevier BV
Published
2005-03
Volume
135
Issue
3
Pages
437-443
ISSN
0022-3166 (ISSN-L)
DOI
10.1093/jn/135.3.437
OpenAlex
W1891721997
Cited by
316
References
51
Citations by year
2026: 14 · 2025: 26 · 2024: 19 · 2023: 19 · 2022: 23 · 2021: 19 · 2020: 20 · 2019: 17 · 2018: 10 · 2017: 13 · 2016: 13 · 2015: 10 · 2014: 18 · 2013: 15 · 2012: 15
FWCI
7.34
Type
journal article
Language
en
Open access
Licence
Locations
  • Journal of Nutrition (publishedVersion)
  • PubMed (publishedVersion)
Funders
Johnson Space Center
Topics
  • Health Sciences › Medicine › Physiology › Spaceflight effects on biology
  • Physical Sciences › Engineering › Aerospace Engineering › Space Exploration and Technology
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Space exploration and regulation
Keywords
astronaut nutrition, long-duration spaceflight, International Space Station, body composition, bone metabolism, bone resorption, bone formation markers, iron metabolism, serum ferritin, hematocrit, acute phase proteins, oxidative stress, 8-hydroxy-2'-deoxyguanosine, superoxide dismutase, vitamin D status, 25-hydroxyvitamin D3, vitamin D supplementation, energy intake, weight loss
MeSH terms
8-Hydroxy-2'-Deoxyguanosine, Acute-Phase Proteins, Adult, Body Composition, Calcifediol, Energy Intake, Deoxyguanosine, Erythrocytes, Female, Humans, International Cooperation, Male, Middle Aged, Nutritional Status, Space Flight, Superoxide Dismutase, Time Factors, Vitamin D, Biomarkers, Oxidative Stress, Astronauts, Dietary Supplements

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