The Importance of magnesium, calcium and phosphate for Health: Balancing Deficiency and Excess

Minerals are essential for various physiological functions, including maintaining skeletal mass, muscle contraction, neural activity, and serving as key components of enzymes and hormones. Since the body cannot synthesise minerals, they must be obtained through diet.

A recent article from Razzaque and Wimalawansa published in Nutrients gives us the opportunity to reflect on the importance of balancing key minerals, to avoid both deficiencies and excess associated with a range of disease risk. The article covers a range of minerals, but I will here focus the blog on Magnesium, Calcium and Phosphate.

Minerals are vital nutrients that regulate critical bodily functions, from bone development and nerve signalling to immune response and enzyme activation. While deficiencies can lead to serious health issues, excessive intake can also be harmful.

Focus on Magnesium, Calcium and Phosphate Functions

• Magnesium (Mg): Essential for muscle contraction, nerve function, and enzyme activation, magnesium also supports DNA/RNA synthesis and stabilises cellular membranes. Deficiency may cause muscle cramps, fatigue, irregular heartbeats, migraines, and osteoporosis. It also plays a role in hormone production by influencing enzyme activity and cellular signalling.

• Vitamin D & Mineral Metabolism: Vitamin D is critical for the absorption and regulation of calcium (Ca) and phosphate, impacting bone health, muscle function, and immune regulation. Deficiency can impair intestinal absorption, renal reabsorption, and bone resorption, leading to fatigue, depression, muscle weakness, and an increased risk of fractures. Magnesium and zinc are essential for activating vitamin D receptors, ensuring its proper function.

• Calcium & Phosphate Balance: While calcium is crucial for bone strength and muscle function, an imbalance—especially excessive phosphate intake from processed foods—can contribute to cardiovascular calcification, metabolic disorders, and accelerated aging.

Let’s dive into this a little more: calcium, magnesium, vitamin D and phosphate relationships

Calcium (Ca) and Magnesium (Mg) Balance in Physiology

Calcium (Ca) is essential for bone health, muscle contraction, nerve signaling, and blood clotting. Most Ca is stored in bones and teeth, acting as a reservoir for maintaining extracellular Ca levels. Adequate intake prevents osteoporosis, particularly in aging populations and postmenopausal women. Deficiency can cause numbness, muscle cramps, arrhythmias, and fractures, while excessive intake may lead to hypercalcemia, kidney stones, and vascular calcification. Hypocalcemia, caused by dietary insufficiency, vitamin D deficiency, or renal dysfunction, requires treatment with Ca supplementation and vitamin D. Hypercalcemia, often due to hyperparathyroidism or malignancies, is managed with hydration, bisphosphonates, and, in severe cases, dialysis.

Magnesium (Mg) plays a crucial role in enzyme activation, muscle and nerve function, and cellular signaling. Deficiency can cause muscle weakness, cramps, fatigue, and cardiac arrhythmias, and is linked to osteoporosis, hypertension, and insulin resistance. Hypomagnesemia also disrupts vitamin D activity and immune function, exacerbating metabolic and inflammatory conditions. Hypermagnesemia, often from renal dysfunction or excessive intake, leads to neuromuscular suppression, hypotension, and in severe cases, cardiac arrest. Treatment involves Mg supplementation for deficiency and IV calcium gluconate or dialysis for excess.

Ca–Mg Balance and Health
The Ca-to-Mg ratio is critical for neuromuscular function, cardiovascular health, and vitamin D metabolism. A high Ca:Mg ratio (>2.6) is linked to chronic diseases, including metabolic syndrome, cardiovascular issues, and osteoporosis, while a low ratio (<1.7) can also increase health risks. Maintaining an optimal Ca:Mg ratio (~2.0) supports enzymatic functions, proper vitamin D activation, and disease prevention.

Vitamin D and Ca–Mg Interaction
Vitamin D regulates Ca and phosphorus metabolism, supporting bone health. Mg is required for vitamin D activation and receptor function, and imbalances in Ca:Mg can impair vitamin D efficiency. Proper Mg levels enhance vitamin D efficacy, reduce inflammation, and support metabolic functions.

Overall, maintaining balanced Ca and Mg intake is essential for optimal health, preventing deficiencies, and supporting physiological functions, particularly in at-risk populations.

Calcium (Ca) and Magnesium (Mg) Interactions with Parathyroid Hormone (PTH)

• PTH regulates Ca and Mg, but Ca is the primary determinant of PTH levels.

• Ca and phosphate metabolism are regulated by PTH, vitamin D, FGF23, and calcitonin.

• Mg acts as a Ca antagonist, functioning as a Ca channel blocker.

• High Ca:Mg ratios can suppress PTH and vitamin D synthesis, leading to reduced Ca and Mg absorption.

• Mg supplementation may correct vitamin D deficiencies caused by high Ca levels.

Impact of Ca:Mg Ratio on Non-Mineral Disorders

• A low Ca:Mg ratio (low Ca) can trigger secondary hyperparathyroidism.

• A high Ca:Mg ratio (low Mg) can cause idiopathic hypoparathyroidism.

• Western diets are typically high in Ca and low in Mg, leading to imbalanced ratios.

• High Ca:Mg ratios in groundwater may cause chronic kidney disease (CKD-CTN).

• Mg supplementation can help prevent unnecessary parathyroidectomy surgeries.

Phosphate and Human Health

• Phosphate is essential for ATP production, bone mineralisation, and DNA synthesis.

• It is regulated by PTH, FGF23, klotho, and vitamin D.

• High dietary phosphate intake is linked to type 2 diabetes and cardiovascular diseases.

• Excess phosphate can impair insulin sensitivity, increase LDL cholesterol, and promote vascular calcification.

Hyperphosphatemia (High Phosphate Levels)

• Causes: Kidney dysfunction, high phosphate intake, hypoparathyroidism.

• Can lead to vascular calcification, bone disorders, and increased cardiovascular mortality.

• Treatment: Dietary restriction, phosphate binders (Ca acetate, sevelamer), dialysis for severe cases.

Hypophosphatemia (Low Phosphate Levels)

• Causes: Malnutrition, chronic alcohol use, vitamin D deficiency, refeeding syndrome.

• Symptoms: Fatigue, muscle weakness, neurological impairments, respiratory failure.

• Treatment: Dietary phosphate intake, oral or IV phosphate supplements for severe cases.

Maintaining optimal Ca:Mg and phosphate balance is crucial for preventing metabolic disorders, bone diseases, and kidney dysfunctions and maintaining optimal neurological function.

Testing recommendations: Blood calcium, phosphate, PTH, vitamin D levels, Alkaline Phosphatase, Protein Total, Albumin, Globulin, magnesium.

The Risks of Mineral Imbalances

Both deficiency and excess can lead to health issues:

• Low mineral levels may contribute to osteoporosis, anemia, immune dysfunction, and cardiovascular disease.

• Excessive intake, particularly from processed foods and supplements (without proper monitoring), can lead to organ damage, metabolic disorders, and accelerated aging.

Who Is at Risk?

Certain groups, including pregnant women, the elderly, vegetarians/vegans, and those with restrictive diets or medical conditions, may require targeted supplementation under medical supervision. Given the nonspecific symptoms of mineral deficiencies, blood tests can provide valuable insights into underlying imbalances.

Final Thoughts

A balanced diet rich in whole foods typically provides sufficient minerals, but awareness of specific nutrient roles and potential deficiencies is key to optimal health and disease prevention. Public health education and dietary guidance remain essential in minimising risks associated with both mineral deficiencies and toxicities.