Adequate protein intake (high by current US standards, IMO) is critical for maintaining bone mass in older women.

Research findings support a positive relationship between protein intake & bone health

Many epidemiological studies have found a significant positive relationship between protein intake and bone mineral density.

Protein intake has also been inversely associated with hip fracture in postmenopausal women.

Isotopic studies have demonstrated greater calcium retention and absorption among individuals consuming higher protein diets, particularly when the calcium content of the diet is limiting.

Protein may positively impact bone health by several mechanisms

Experimental feeding studies have demonstrated that protein increases intestinal calcium absorption, and may positively affect bone turnover markers.

Dietary protein is an important regulator of IGF-1, which is anabolic to bone and muscle.

Maintenance of bone strength is dependent upon maintenance of muscle mass, which exerts a trophic effect on bone by the force applied during muscle contraction.

Adequate dietary protein plays an important role in the continuous remodeling process that occurs in bone.