Nutrition and Bone Health in Space
Smith, Scott M., et al. (2015). "Nutrition and Bone Health in Space." Nutrition and Bone Health
The effect of weightlessness on the human skeletal system is one of the greatest concerns in safely extending space missions [1–11]. The ability to understand and counteract weightlessness-induced bone mineral loss will be vital to crew health and safety during and after extended-duration space sta- tion and exploration missions [1–7]. Research on bone mineral loss during space flight has gone on for more than half a century, and recent studies have shown significant progress in developing coun- termeasures that have proved to be effective, including good nutrition and exercise. We review the history of this research here and provide a summary of recent and ongoing studies, including efforts to counteract bone and calcium loss resulting from weightlessness. Unfortunately, the most obvious nutritional countermeasure—providing excess calcium—does not protect against bone loss . This result is likely related to the decreased calcium absorption observed in space flight and in ground-based models [13–16]. Phosphate supplementation was also ineffective at reducing calcium excretion . Combination therapy with calcium and phosphorus was also unsuccessful at mitigating bone loss and hypercalciuria . Other nutrients, specifically sodium, protein, potassium, vitamin K, and omega-3 fatty acids, have also been proposed and/or tested as bone loss countermeasures , and are discussed in more detail below.