Iron Bisglycinate vs Manganese

Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.

⚠️ Known Interaction
MEDIUM Manganese and iron share DMT1 transporter — high iron intake reduces Mn absorption and vice versa
Iron BisglycinateManganese
CategoryMineralsMinerals
Standard Dose25-36mg elemental iron (as bisglycinate) daily for deficiency correction2-5mg daily
TimingOn 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.With food. Often included in multimineral formulas.
Cycle DurationUntil ferritin >50 ng/mL, then reassess (typically 3-6 months). Not for ongoing supplementation unless chronic blood loss.ongoing (typically via multi-mineral or bone support formula)
Evidence Levelstrong_humanmoderate_human

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

Best Stacking Partners

Vitamin C (doubles non-heme iron absorption)B12 (if concurrent deficiency)Folate
B

Manganese

Minerals

Mechanism

Manganese is a cofactor for manganese superoxide dismutase (MnSOD/SOD2, the primary mitochondrial antioxidant enzyme), arginase (urea cycle), pyruvate carboxylase (gluconeogenesis), glutamine synthetase (ammonia detoxification in brain), and glycosyltransferases (proteoglycan/GAG synthesis for cartilage and bone). It activates several kinases and phosphatases involved in cell signaling. Manganese is essential for bone formation, cartilage integrity, and reproductive function.

Standard Dosing

2-5mg daily

Timing

With food. Often included in multimineral formulas.

Cycle Duration

ongoing (typically via multi-mineral or bone support formula)

Side Effects

  • Generally well tolerated at standard doses
  • Neurotoxicity at chronic high exposure (manganism — Parkinson-like syndrome)
  • GI upset
  • Headache

Contraindications

  • Liver disease (Mn is hepatically cleared — accumulation risk)
  • Iron deficiency (upregulated DMT1 increases Mn brain accumulation)
  • Chronic occupational Mn exposure

Best Stacking Partners

CalciumVitamin D3GlucosamineCollagen

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