A tight control of magnesium homeostasis seems to be crucial for bone health. On the basis of experimental and epidemiological studies, both low and high magnesium have harmful effects on the bones. Magnesium deficiency contributes to osteoporosis directly by acting on crystal formation and on bone cells and indirectly by impacting on the secretion and the activity of parathyroid hormone and by promoting low grade inflammation. Less is known about the mechanisms responsible for the mineralization defects observed when magnesium is elevated. Overall, controlling and maintaining magnesium homeostasis represents a helpful intervention to maintain bone integrity.
Osteoporosis is a multifactorial disease characterized by loss of bone mass due to a marked bone microarchitecture deterioration . Physiologically, bone is constantly remodeled by concerted and coordinated interactions between osteoclasts, the cells primarily involved in bone resorption, and osteoblasts, which ensure bone formation and mineralization. Osteoporosis results from an imbalance between bone deposition and resorption. The consequent decline of bone mass increases the risk of fractures, in particular hip and spine fractures, which are associated with substantial pain and suffering, disability, and even death . Osteoporosis affects millions people worldwide, predominantly postmenopausal women. In the United States low bone mass is a threat for more than 40 million people . In Europe, the prevalence of osteoporosis is expected to affect more than 30 million people by the year 2050 . Frequently associated with aging, osteoporosis is a major health concern since the aging population will double over the next decade with enormous cost burden on the healthcare systems. Osteoporosis therapies are available and fall into two classes, anabolic drugs, which induce bone formation, and anti-resorptive drugs, which retard bone resorption. In addition, modifications of lifestyle, i.e., regular physical activity, no alcohol, no smoke, balanced diet, are highly recommended in patients with osteoporosis . In general, because osteoporosis reflects peak bone mass determined by factors preceding skeletal maturity , there is a growing interest in preventive strategies for decreasing the incidence of osteoporosis in future decades. Dietary interventions are among them. Indeed, nutritional factors are of particular importance to bone health and they are modifiable by providing food-based recommendations. A correct diet is particularly important in the young, before skeletal maturity is reached. While calcium and vitamin D have been the master focus of nutritional prevention of osteoporosis, several additional food constituents—such as phytoestrogens, flavonoids, vitamins A, B, C, E, folate—and minerals among which copper, zinc, selenium, iron fluoride and magnesium (Mg), are known to be important . In particular, a significant association has been found between bone density and the intake of Mg, an essential micronutrient with a wide range of metabolic, structural and regulatory functions .