Osteoporosis concerns 50% of women over 80 years. Prevalence of energizing and protein malnutrition is high as for institutional elderly people as for community dwelling elderly people. Malnutrition, physical inactivity and many etiological factors lead to tissular losses especially on protein compartment, named sarcopenia. Among the common etiological factors, some cytokines have an effect on proteolysis and bone restructuring, interfering with osteoclast metabolism. Inflammation or stress, mechanisms which product cytokines, are responsible for unfavourable bone restructuring and for a loss of protein mass, deteriorating the muscular functional prognostic. We researched articles on Medline® between 1980 and 2010 about relations between protein compartment, malnutrition and bone density. Several studies in literature suggest that increase in protein intake in daily caloric needs could have a positive effect on bone mineral density and functional performances (in primary prevention as in secondary prevention). So, primary and secondary preventive measures must comprise an increase in protein intake and a sufficient physical activity.