Benefits for bone from resistance exercise and nutrition in long-duration spaceflight:

Evidence from biochemistry and densitometry

Journal of bone and Mineral Research Volume 27 Issue 9 (September 2012)
Authors
Scott M Smith, Martina A Heer, Linda C Shackelford, Jean D Sibonga, Lori Ploutz-Snyder, Sara R Zwart

Exercise has shown little success in mitigating bone loss from long-duration spaceflight. The first crews of the International Space Station (ISS) used the “interim resistive exercise device” (iRED), which allowed loads of up to 297 lbf (or 1337 N) but provided little protection of bone or no greater protection than aerobic exercise. In 2008, the Advanced Resistive Exercise Device (ARED), which allowed absolute loads of up to 600 lbf (1675 N), was launched to the ISS. We report dietary intake, bone densitometry, and biochemical markers in 13 crewmembers on ISS missions from 2006 to 2009. Of these 13, 8 had access to the iRED and 5 had access to the ARED. In both groups, bone-specific alkaline phosphatase tended to increase during flight toward the end of the mission (p=0.06) and increased 30 days after landing (p<0.001). Most markers of bone resorption were also increased in both groups during flight and 30 days after landing (p<0.05). Bone densitometry revealed significant interactions (time and exercise device) for pelvis bone mineral density (BMD) and bone mineral content (p<0.01), hip femoral neck BMD (p<0.05), trochanter BMD (p<0.05), and total hip BMD (p<.05). These variables were unchanged from preflight only for ARED crewmembers, who also returned from flight with higher percent lean mass and lower percent fat mass. Body mass was unchanged after flight in both groups.

All crewmembers had nominal vitamin D status (75± 17 nmol/L) before and during flight. These data document that resistance exercise, coupled with adequate energy intake (shown by maintenance of body mass determined by dual-energy X-ray absorptiometry [DXA]) and vitamin D, can maintain bone in most regions during 4- to 6-month missions in microgravity. This is the first evidence that improving nutrition and resistance exercise during spaceflight can attenuate the expected BMD deficits previously observed after prolonged missions.

Start of Introduction from the PDF

Bone loss is a seemingly inevitable outcome of spaceflight.(1–4)
Of the many countermeasures evaluated to date, none have been fully effective during flight.(5)
Exercise in particular has been applied in many forms over the past 4 decades of spaceflight,
with little success in mitigating net bone loss. This was initially assumed to be related to the types of exercise available.

PDF is attached at the bottom of this page
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It is amazing that it took 40 years of space flight for NASA to realize that the crewmembers, who got no UV, were not getting enough vitamin D

Apparently NASA finally supplemented with 400 IU of vitamin in the 1990's
NASA later increased the supplementation from 400 to 800 IU
We anticipate that NASA Spacestation and the NAVY submarines crewmembers will have 2,000 IU daily in the future - like crewmembers in the Antartic

Crewmember compliance not very good ( not take the vitamin D supplements)

65% in one group and 91% in another

NASA thinks spacestation personnel only need 800 IU of vitamin D – Sept 2012

Benefits for bone from resistance exercise and nutrition in long-duration spaceflight:

Evidence from biochemistry and densitometry

Start of Introduction from the PDF

It is amazing that it took 40 years of space flight for NASA to realize that the crewmembers, who got no UV, were not getting enough vitamin D

Crewmember compliance not very good ( not take the vitamin D supplements)

See also VitaminDWiki