Iron Bisglycinate vs Potassium (Citrate)

Mechanism

Iron is essential for hemoglobin (oxygen transport), myoglobin (muscle oxygen storage), cytochrome enzymes (electron transport chain — Complexes I, II, III, IV), cytochrome P450 enzymes (drug/hormone metabolism), catalase (H2O2 decomposition), ribonucleotide reductase (DNA synthesis), and aconitase (Krebs cycle). Iron bisglycinate (Ferrochel) uses amino acid chelation to bypass the normal DMT1/ferroportin pathway, instead being absorbed intact via PepT1 transporter. This mechanism avoids the GI side effects of ionic iron (free Fe2+ generates hydroxyl radicals via Fenton reaction in the gut lumen) and is not inhibited by phytates, tannins, or calcium.

Standard Dosing

25-36mg elemental iron (as bisglycinate) daily for deficiency correction

Timing

On empty stomach or with vitamin C for absorption. Alternate day dosing (every other day) may be superior due to hepcidin cycling. Separate from calcium, zinc, tea, coffee by 2+ hours.

Cycle Duration

Until ferritin >50 ng/mL, then reassess (typically 3-6 months). Not for ongoing supplementation unless chronic blood loss.

Side Effects

• GI distress (significantly less than ferrous sulfate)
• Constipation (less common with bisglycinate)
• Dark stools
• Nausea
• Iron overload if supplemented unnecessarily

Contraindications

• Hemochromatosis
• Iron overload conditions
• Thalassemia (without documented deficiency)
• Hemolytic anemias (unless also iron deficient)
• Chronic transfusion therapy

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Mechanism

Potassium is the principal intracellular cation, maintaining resting membrane potential (-70 to -90mV) via the Na+/K+-ATPase pump (3 Na+ out, 2 K+ in per ATP). It is essential for: cardiac rhythmicity (phase 3 repolarization of cardiac action potential), skeletal muscle contraction, nerve impulse transmission, acid-base balance (exchanged for H+ in renal tubules), blood pressure regulation (promotes natriuresis via renal sodium excretion), and insulin secretion. Citrate form provides alkalinizing anion that inhibits calcium oxalate and uric acid kidney stone formation.

Standard Dosing

99-200mg per capsule (regulatory limit in US); dietary target 3500-4700mg/day total

Timing

With meals, divided throughout the day. Slow-release forms preferred for higher doses.

Cycle Duration

ongoing

Side Effects

• GI irritation/ulceration (non-microencapsulated forms)
• Nausea
• Diarrhea
• Hyperkalemia (dangerous — cardiac arrhythmias)

Contraindications

• Hyperkalemia
• Renal insufficiency (impaired K+ excretion)
• Addison's disease (aldosterone deficiency)
• Concurrent ACE inhibitor/ARB + potassium-sparing diuretic

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