[Malnutrition and osteoporosis].

Undernutrition, particularly protein undernutrition, contributes to the occurrence of osteoporotic fracture, by lowering bone mass and altering muscle strength. Furthermore, the rate of medical complications after fracture can also be increased by nutritional deficiency. The IGF-I system appears to be directly involved in the pathogenetic mechanisms leading to osteoporotic hip fracture in elderly and to its complications. In the presence of adequate calcium and vitamin D supplies, protein supplements increasing the intakes from low to normal, raises IGF-I levels, improves the clinical outcome after hip fracture, and attenuates the decrease in proximal femur bone mineral density in the year following the fracture. This nutritional approach is associated with a significant reduction of the stay in rehabilitation hospital. This underlines the importance of nutritional supports in preventing and healing osteoporotic fractures.