Essential Minerals: The Complete Clinical Reference

The Mineral Foundation

If vitamins are the orchestra, minerals are the stage — the structural foundation upon which every biological performance depends. Magnesium participates in over 600 enzymatic reactions. Zinc is required for more than 300. Iron carries the oxygen that keeps every cell alive. Without adequate minerals, the most elegant biochemistry in the world grinds to a halt.

Yet mineral deficiency is pandemic. Industrial agriculture has depleted soils. Processing strips minerals from food. Stress, medications, and modern diets accelerate losses. The average American is deficient in magnesium, potassium, and zinc — three minerals that govern everything from heartbeat to immune defense to mental clarity.

This reference covers macro minerals and trace minerals through the Institute for Functional Medicine lens: clinical dosing, optimal forms, testing, interactions, and the patterns that connect mineral status to chronic disease.

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Part 1: Macro Minerals

Magnesium: The Master Mineral

Magnesium is involved in over 600 enzymatic reactions — ATP production, DNA synthesis, nerve transmission, muscle contraction, blood pressure regulation, bone formation, glutathione synthesis. It is arguably the single most important mineral in clinical practice, and roughly 50-80% of the population is deficient.

Why the epidemic? Modern soils contain 20-30% less magnesium than 50 years ago. Refined grains lose 80-97% of their magnesium. Stress hormones (cortisol, adrenaline) actively dump magnesium through the kidneys. Caffeine, alcohol, PPIs, diuretics, and sweating all accelerate loss.

Testing: Serum magnesium is nearly useless — only 1% of body magnesium is in serum, and the body will strip magnesium from bones and muscles to maintain serum levels until severe depletion. RBC magnesium (red blood cell) is the clinically relevant test. Optimal: 5.5-6.5 mg/dL.

Clinical dosing: 400-800mg elemental magnesium daily, in divided doses.

The six forms and their clinical niches:

• Magnesium glycinate (bisglycinate): Best for sleep, anxiety, and general repletion. Glycine itself is calming. Well-absorbed, minimal GI effects. The workhorse form.
• Magnesium threonate (Magtein): Crosses the blood-brain barrier. Developed at MIT (Bhatt/Sun 2012). Specific for cognitive function, memory, neurological conditions.
• Magnesium citrate: Good absorption, mild laxative effect. Useful when patients also have constipation.
• Magnesium malate: Malic acid supports ATP production in the Krebs cycle. Best for muscle pain, fibromyalgia, and energy.
• Magnesium taurate: Taurine has cardioprotective properties. Best for cardiovascular conditions, arrhythmias, blood pressure.
• Magnesium oxide: Poor absorption (4%) but highest elemental magnesium per pill. Used primarily for bowel tolerance — essentially a laxative form.

Depletion causes to screen for: Chronic stress (cortisol), PPIs (omeprazole blocks absorption), alcohol, caffeine, excessive sweating (athletes), diuretics, diabetes (glycosuria drives Mg loss), aging (absorption decreases).

Calcium: The Mineral That Needs a Team

Calcium has been oversold as a solo supplement and undersold as a team player. The old advice — “take 1,500mg of calcium carbonate for your bones” — is not just outdated, it may be harmful.

The Bolland 2010 meta-analysis in the BMJ showed that calcium supplementation alone (without K2 and D3) increased cardiovascular events by 27-31%. Calcium without direction goes to soft tissues — arterial walls, kidneys (stones), joints — instead of bones.

Clinical principles:

• Food first: Dairy (if tolerated), sardines with bones, dark leafy greens (kale, bok choy — not spinach, whose oxalates block calcium), fortified foods.
• Supplemental calcium: Only when dietary intake is clearly inadequate. Citrate form (better absorbed, doesn’t require stomach acid) over carbonate. Maximum 500mg per dose (absorption drops above this).
• Never alone: Always with vitamin D3 (for absorption), K2 MK-7 (for direction), and magnesium (for balance).

Daily target: 1,000-1,200mg total (food + supplements). Most patients getting adequate dairy or leafy greens need minimal or no supplementation.

Potassium: The Forgotten Electrolyte

Potassium is the most abundant intracellular cation. It governs nerve conduction, muscle contraction (including the heart), fluid balance, and blood pressure. The adequate intake is 4,700mg per day. The average American gets roughly 2,500mg. This gap has cardiovascular consequences.

The sodium-potassium balance: These two minerals exist in a ratio. High sodium with low potassium drives hypertension, fluid retention, and cardiac risk. Increasing potassium is often more effective than restricting sodium for blood pressure — a fact the DASH diet exploits.

Food sources: Avocado (975mg per whole fruit), potato with skin (926mg), sweet potato (542mg), banana (422mg — actually not the best source), coconut water (600mg per cup), salmon (534mg per fillet), white beans (1,004mg per cup).

Supplementation caution: Over-the-counter potassium supplements are limited to 99mg per capsule (FDA regulation) — practically useless for repletion. Prescription potassium chloride is used for measured depletion. For most patients, food-based strategies are more effective. Potassium citrate or bicarbonate forms also provide alkalinizing benefits.

Cardiac implications: Both hypokalemia and hyperkalemia cause arrhythmias. Always check potassium with renal function before supplementing. Loop diuretics deplete potassium; potassium-sparing diuretics can elevate it. Patients on ACE inhibitors or ARBs must monitor carefully.

Sodium: Not the Villain

The war on sodium has been oversimplified. While excessive processed-food sodium is harmful, adequate sodium is essential for nerve function, fluid balance, adrenal health, and nutrient transport.

Adrenal insufficiency and salt craving: Cortisol regulates aldosterone, which controls sodium retention. In HPA axis dysfunction (“adrenal fatigue”), aldosterone drops, sodium wasting increases, and patients crave salt — because they genuinely need it. Clinical dose: 1-2 teaspoons of high-quality sea salt or Himalayan salt daily.

POTS (Postural Orthostatic Tachycardia Syndrome): Salt loading (3-10g sodium daily plus 2-3 liters water) is a first-line treatment, increasing blood volume to prevent orthostatic drops.

Electrolyte balance: Sodium, potassium, magnesium, and chloride work as a unit. You cannot optimize one without considering the others. This is why isolated sodium restriction often fails — it disrupts the whole electrolyte orchestra.

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Part 2: Trace Minerals

Zinc: The Immune Commander

Zinc is required for over 300 enzymes and 1,000+ transcription factors. It governs immune function (thymulin activation, T-cell maturation), testosterone production, gut barrier integrity, skin repair, taste/smell, and DNA synthesis.

Clinical dosing: 15-50mg elemental zinc.

• Zinc picolinate: Excellent absorption.
• Zinc bisglycinate: Gentle on the stomach.
• Zinc carnosine (ZnC): Specifically studied for gut mucosal repair (Mahmood 2007). The go-to form for gut healing protocols.

The copper ratio: Zinc and copper compete for absorption. Chronic zinc supplementation above 30mg without copper causes copper deficiency — manifesting as anemia, neutropenia, and neurological symptoms. Maintain a 10:1 to 15:1 zinc-to-copper ratio. If supplementing 50mg zinc, add 2-5mg copper.

Zinc taste test (zinc tally): Swish liquid zinc sulfate in the mouth. If you taste nothing — you’re deficient. If it tastes metallic — you’re adequate. Simple, cheap, useful as a screening tool.

Phytate interference: Grains, legumes, and nuts contain phytic acid that binds zinc. Vegetarians and vegans are at higher deficiency risk. Soaking, sprouting, and fermenting reduce phytate content.

Selenium: The Thyroid Guardian

Selenium is essential for thyroid hormone conversion (deiodinase enzymes convert T4 to T3), glutathione peroxidase (antioxidant defense), and immune regulation.

Clinical dosing: 200 mcg selenomethionine daily.

Thyroid autoimmunity: The Toulis 2010 meta-analysis showed selenium supplementation reduced TPO antibodies by 40% in Hashimoto’s thyroiditis. The thyroid contains more selenium per gram than any other organ. Selenium deficiency is essentially thyroid sabotage.

Glutathione peroxidase: Selenium is the catalytic center of this enzyme — the primary defense against hydrogen peroxide and lipid peroxides. Without selenium, glutathione cannot do its antioxidant job.

Brazil nuts: One to two Brazil nuts daily provides approximately 75-150 mcg selenium — the simplest “supplement” possible. But selenium content varies dramatically by soil (Brazilian soil vs North American).

Toxicity: Above 400 mcg daily causes selenosis — garlic breath, hair loss, nail brittleness, fatigue, GI disturbance. The therapeutic window is relatively narrow.

Iron: Handle with Precision

Iron is the most dangerous mineral to supplement carelessly. Too little causes anemia, fatigue, hair loss, impaired cognition, and immune dysfunction. Too much generates devastating oxidative stress through Fenton chemistry — free iron catalyzes hydroxyl radical formation, the most destructive free radical in biology.

Never supplement iron without testing. This is a hard clinical rule.

Testing panel:

• Ferritin: Storage iron. Optimal >50 ng/mL (general), >70 ng/mL (thyroid/hair). Below 30 is unequivocal deficiency.
• Serum iron, TIBC, transferrin saturation: Distinguish iron deficiency from iron overload.
• Hepcidin: The master iron regulator. Elevated in inflammation (blocks iron absorption — “anemia of chronic disease”).

Preferred form: Iron bisglycinate (Ferrochel) — well-absorbed, minimal GI side effects. Take on empty stomach with vitamin C for enhanced absorption. Avoid with tea, coffee, calcium, or dairy (all block absorption).

Every-other-day dosing (Stoffel 2017): Groundbreaking research showed that iron supplementation triggers hepcidin release, which blocks absorption for 24 hours. Dosing every other day actually results in better total absorption than daily dosing. This also reduces GI side effects.

Hemochromatosis (HFE gene): Hereditary iron overload affects 1 in 200-300 people of Northern European descent. C282Y and H63D mutations. Ferritin above 300 ng/mL in men or 200 in women warrants HFE gene testing. Treatment is therapeutic phlebotomy.

Iodine: The Thyroid Fuel

Iodine is required for thyroid hormone synthesis (T4 has four iodine atoms, T3 has three). Also concentrated in breast tissue, ovaries, prostate, and salivary glands.

Maintenance dosing: 150-400 mcg (RDA level). Food sources: seaweed, kelp, fish, dairy, iodized salt.

Therapeutic dosing debate: Practitioners like David Brownstein advocate higher doses (3-12.5mg) for thyroid optimization, fibrocystic breast disease, and cancer prevention, referencing Japanese intake levels. Others caution that high-dose iodine can trigger the Wolff-Chaikoff effect — temporary suppression of thyroid hormone synthesis.

Hashimoto’s caution: Iodine can exacerbate autoimmune thyroiditis by increasing TPO activity and providing more substrate for autoimmune attack. Start low (150-300mcg) with selenium always on board. Monitor antibodies.

Copper: The Double Agent

Copper is essential (1-2mg daily) for ceruloplasmin, cytochrome c oxidase, superoxide dismutase, collagen cross-linking, and iron metabolism. But excess copper is neurotoxic.

Zinc depletion of copper: High-dose zinc therapy depletes copper. Symptoms of copper deficiency mimic B12 deficiency — anemia, neuropathy, neutropenia.

Wilson’s disease: Genetic copper accumulation (ATP7B mutations). Kayser-Fleischer rings in the eyes, liver damage, psychiatric symptoms. Low ceruloplasmin on testing.

Chromium: The Insulin Sensitizer

Chromium picolinate 200-1000 mcg improves insulin receptor sensitivity by amplifying insulin signaling. Clinically useful for blood sugar management, PCOS, and metabolic syndrome. Anderson 1997 showed significant HbA1c and fasting glucose improvement at 1000 mcg in type 2 diabetes.

Boron: The Forgotten Bone Mineral

Boron (3-10mg daily) influences testosterone metabolism, reduces SHBG (increasing free testosterone), supports calcium and magnesium metabolism, improves bone density, and has anti-inflammatory properties. Naghii 2011 showed a 28% increase in free testosterone with 10mg daily for one week. Widely underutilized.

Manganese: The SOD Cofactor

Manganese (2-5mg daily) is the catalytic center of mitochondrial SOD2 (superoxide dismutase) — a primary defense against mitochondrial free radicals. Also required for bone formation, blood sugar regulation, and wound healing. Deficiency is rare but occurs with high iron or calcium intake (competition).

Molybdenum: The Detox Mineral

Molybdenum (100-500mcg daily) activates three crucial enzymes: sulfite oxidase (detoxifies sulfites — relevant for sulfite sensitivity), aldehyde oxidase (breaks down acetaldehyde — relevant during Candida die-off), and xanthine oxidase (purine metabolism).

Clinically valuable during antifungal protocols when patients experience die-off reactions. Acetaldehyde from Candida die-off causes brain fog, headaches, and malaise — molybdenum helps clear it.

Lithium Orotate: The Micro-Dose Neuroprotector

Lithium orotate (5-20mg) is fundamentally different from prescription lithium carbonate (900-1800mg). The orotate form delivers lithium directly to cells at micro-doses, without the nephrotoxicity or thyroid suppression of pharmaceutical lithium.

Clinical applications: Neuroprotection (reduces brain volume loss — Forlenza 2012), mood stabilization, BDNF upregulation, anti-inflammatory, reduced suicidality (geographical studies show lower suicide rates in areas with higher lithium in drinking water — Ohgami 2009).

Dosing: 5-20mg lithium orotate daily. No kidney monitoring required at these doses.

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The Mineral Network: IFM Systems Thinking

Minerals don’t work in isolation — they exist in webs of interaction:

• Zinc competes with copper and iron for absorption
• Magnesium is required for vitamin D activation and calcium regulation
• Selenium is required for thyroid hormone conversion and glutathione function
• Potassium and sodium balance each other across every cell membrane
• Iron and copper collaborate in hemoglobin synthesis
• Boron modulates calcium, magnesium, and phosphorus metabolism

The functional medicine approach is to test broadly, supplement specifically, and retest. A comprehensive mineral assessment includes RBC magnesium, zinc (plasma or RBC), selenium, ferritin panel, copper/ceruloplasmin, iodine (24-hour urine loading test), and standard electrolytes.

Every chronic disease involves mineral dysregulation. Every medication depletes specific minerals. Every stress response accelerates mineral loss. When you understand the mineral network, you understand why replenishing these foundations is often the first and most impactful therapeutic step.

If the body is a garden, minerals are the soil. What grows in depleted soil?