Essential Minerals Guide

Role: Cofactor in 300+ enzymatic reactions. Regulates muscle/nerve function, blood sugar, blood pressure, and protein synthesis.

Deficiency signs: Muscle cramps, insomnia, anxiety, irregular heartbeat, fatigue. ~50% of US adults are below the EAR.

RDA: 400-420 mg (men), 310-320 mg (women)

Best food sources: Pumpkin seeds, spinach, dark chocolate, almonds, black beans

Best supplement form: Glycinate (best absorbed, least GI issues). Threonate for cognitive support. Avoid oxide (4% absorption).

Role: Immune function, wound healing, DNA synthesis, taste/smell. Required for 100+ enzymes.

Deficiency signs: Frequent illness, slow wound healing, hair loss, loss of taste/smell, white spots on nails.

RDA: 11 mg (men), 8 mg (women)

Best food sources: Oysters (74 mg per serving), beef, pumpkin seeds, lentils, cashews

Best supplement form: Picolinate or bisglycinate. Always pair with copper (2mg Cu per 15mg Zn) to prevent depletion.

Role: Oxygen transport (hemoglobin), energy production, DNA synthesis. Most common deficiency worldwide.

Deficiency signs: Fatigue, pale skin, shortness of breath, cold extremities, brittle nails, restless legs.

RDA: 8 mg (men), 18 mg (premenopausal women), 8 mg (post-menopause)

Best food sources: Red meat, liver, lentils, spinach, fortified cereals. Heme iron (meat) absorbs 15-35% vs non-heme 2-20%.

Best supplement form: Iron bisglycinate (gentle on stomach, well absorbed). Avoid sulfate if GI-sensitive. Take with vitamin C, away from calcium.

Role: Thyroid hormone conversion (T4 to T3), antioxidant defense via glutathione peroxidase, immune modulation.

Deficiency signs: Thyroid dysfunction, weakened immunity, cognitive decline, Keshan disease (cardiomyopathy).

RDA: 55 mcg. Toxicity starts at ~400 mcg/day.

Best food sources: Brazil nuts (1-2 nuts = daily requirement), tuna, sardines, eggs, sunflower seeds

Best supplement form: Selenomethionine (organic, well absorbed). Avoid sodium selenite (inorganic, pro-oxidant at high doses).

Role: Bone/teeth structure (99% stored in bones), muscle contraction, nerve signaling, blood clotting.

Deficiency signs: Osteoporosis, muscle spasms, numbness/tingling, brittle nails. Often subclinical for decades.

RDA: 1,000 mg (adults), 1,200 mg (women 51+, men 71+)

Best food sources: Dairy, sardines with bones, kale, broccoli, fortified plant milks

Best supplement form: Calcium citrate (absorbs on empty stomach, better for low-acid). Split doses under 500mg. Must pair with D3 and K2.

Role: Fluid balance, nerve transmission, muscle contraction, blood pressure regulation. Counterbalances sodium.

Deficiency signs: Muscle weakness, cramps, constipation, heart palpitations. Most adults get ~50% of adequate intake.

RDA: 2,600 mg (women), 3,400 mg (men). OTC supplements capped at 99mg per pill (FDA rule).

Best food sources: Potatoes, bananas, avocados, sweet potatoes, white beans, coconut water

Best supplement form: Potassium citrate or gluconate. Due to FDA capsule limits, food sources are primary. Supplement only under guidance.

Role: Thyroid hormone synthesis (T3 and T4). Critical during pregnancy for fetal brain development.

Deficiency signs: Goiter, hypothyroidism, fatigue, weight gain, cognitive impairment. Deficiency rising as dairy intake drops.

RDA: 150 mcg (adults), 220 mcg (pregnancy), 290 mcg (lactation)

Best food sources: Seaweed (kelp can exceed UL), cod, dairy, iodized salt, eggs

Best supplement form: Potassium iodide. Caution with kelp supplements (iodine content varies wildly, some exceed 1,000 mcg/serving).

Role: Enhances insulin signaling and glucose metabolism. May improve insulin sensitivity in type 2 diabetes.

Deficiency signs: Impaired glucose tolerance, elevated blood sugar, neuropathy. Rare in isolation but common in metabolic syndrome.

RDA: 35 mcg (men), 25 mcg (women). No established UL.

Best food sources: Broccoli, grape juice, whole grains, garlic, basil

Best supplement form: Chromium picolinate (most studied). GTF chromium (from yeast) also effective. Evidence strongest for insulin resistance.