Several studies have highlighted the increased risk of developing osteoporosis in magnesium deficient individuals due to the importance of this mineral at regulating a myriad of fundamental processes in maintaining bone health.
Osteoporosis is a medical condition that affects millions of individuals worldwide and is characterised by loss of bone mass; increasing the risk of falls, fractures and causing excessive pain with small knocks. This disease is multifactorial, meaning that there are multiple factors that contribute to its development; the two most common being aging and post-menopause. Normally, our bones are constantly being remodelled by two types of cells known as osteoclasts and osteoblasts. Osteoclasts drill the bone to release minerals such as calcium into the blood; meanwhile osteoblasts fill in the gaps, increasing bone density.
However, in osteoporotic individuals there is an imbalance between these cells and the activity of the bone removing osteoclasts overrules that of osteoblasts. Ultimately with time you end up with bones that have an adversely altered architecture due to the severe loss of tissue, something which makes bones weak and fragile. Multiple studies have shown that there is a clear link between magnesium deficiency in different animal species (including humans) and osteoporosis. Furthermore, animals that are given very low magnesium diets develop brittle bones that fracture easily, highlighting the importance of this mineral.
Figure 1. a) In healthy individuals, the activity of osteoclasts and osteoblasts is balanced and bone turnover occurs normally. b) However, in osteoporotic individuals the activity of the osteoclasts increases dramatically and that of osteoblasts diminishes; resulting in a serious loss of bone mass that raises the risk of falls and fractures.
The current western diet is high in sugars, saturated fats, salt and very low in magnesium; meaning that many people have very low levels of this mineral and may help explain the high prevalence of osteoporosis worldwide. Researchers have demonstrated that magnesium has a series of direct and indirect effects that are elemental for maintaining bone integrity and preventing osteoporosis.
Magnesium increases the production of a molecule known as Nitric Oxide which reduces the activity of the bone removing osteoclasts. Furthermore, this mineral effectively increases the activity of osteoblasts; consequently allowing adequate bone deposition. The current drugs that have been developed for treating osteoporosis target these cells and they either enhance osteoblast activity or lessen osteoclast activity. Fascinatingly, having adequate levels of Magnesium effectively achieves similar effects to such drugs but without any added side effects!
Figure 2. Magnesium directly increases bone density by reducing the function of osteoclasts and increasing the activity of osteoblasts.
Besides its direct effects upon bone structure, magnesium is essential for the skeleton due to its role at regulating calcium levels by affecting the levels of both Vitamin D and Parathyroid Hormone (PTH). Both Vitamin D and PTH are essential at ensuring that calcium is absorbed and utilised to increase bone deposition.
Magnesium increases the synthesis of PTH which in turn switches an enzyme known as 1-hydroxylase that activates Vitamin D into its functional form (1,25-dihydroxyvitamin D3). Having low levels of magnesium negatively affects Vitamin D function due to the direct reduction of PTH production. Ultimately, this leads to a reduction in calcium absorption and as a result bones become weaker over time, increasing the chances of developing osteoporosis.
Figure 3. The importance of magnesium at maintaining adequate calcium levels. Magnesium increases the production of PTH which then increases the activity of the enzyme 1-hydroxylase. This enzyme is essential in order for Vitamin D to absorb calcium effectively into the body; which may then be deposited in the bones to strengthen them.
Additionally, other studies have highlighted that magnesium deficiency increases inflammation markers that are responsible for promoting bone loss by dramatically increasing the activity of osteoclasts.
Overall, since magnesium is involved in the regulation of multiple processes that affect bone health and because it’s deficiency is associated with osteoporosis, this mineral could potentially be used as a magic bullet in the near future to tackle a condition that is both an economical and physical burden worldwide.
Castiglioni, S., Cazzaniga, A., Albisetti, W. & Maier, J.A.M. (2013). Magnesium and Osteoporosis: Current State of Knowledge and Future Research Directions. Nutrients, 5, 3022-3033.
Johnson, S. (2001). The multifaceted and widespread pathology of magnesium deficiency. Medical Hypotheses, 56(2), 163-170.