Recommendations for dietary calcium intake and bone health: the role of health literacy

Osteoporosis, a common disease of the skeleton, involves microarchitectural
deterioration of the bone matrix and depletion of bone
mineral; this results in an increased susceptibility to fracture [1]. Postfracture,
there is a plethora of financial, personal and psychosocial
outcomes, including reduced mobility, impairment of daily activities,
inability to work and loss of confidence [2,3]. A hip fracture has the
most severe implications: one in five individuals die within the first
year, while 60% of individuals who survive a hip fracture still require
assistance to walk one year later, and 33% are totally dependent or are
admitted to a nursing home [2,4]. Bone mass is an important predictor
of osteoporosis, and future fracture risk [5], and calcium plays an
important role in normal growth, development and maintenance of the
skeleton [6], including providing a dynamic store to maintain the
intra- and extra-cellular calcium pools [7]. Calcium homeostasis is
regulated by an integrated hormonal system that involves calcitonin,
parathyroid hormone (PTH) and the PTH receptor, and 1,25-
dihydroxyvitamin D and the vitamin D receptor [7,8], along with
serum ionized calcium, and the calcium-sensing receptor [9]. When
plasma concentrations of ionized calcium fall below optimal levels,
bone resorption increases in order to restore the mineral equilibrium.