# item.guide
Side-by-Side Comparison Essential Vitamins & Minerals

Iron (Heme & Non-Heme) vs. Vitamin B12 (Cobalamin)

Comparing 2 standards across 9 specifications. 9 key differences identified.

Comparing:
Iron (Heme & Non-Heme)
Vitamin B12 (Cobalamin)
Iron (Heme & Non-Heme) →

Iron is an essential redox trace element central to hemoglobin oxygen transport, myoglobin storage, and mitochondrial electron transport chain cytochromes. Adult RDA is 8mg (men/post-menopausal women) / 18mg (pre-menopausal women), with a Tolerable Upper Limit of 45mg/day.

View full Iron (Heme & Non-Heme) spec sheet →
Vitamin B12 (Cobalamin) →

Vitamin B12 is a cobalt-containing water-soluble corrinoid synthesized exclusively by microorganisms. Adult RDA is 2.4µg/day (no Upper Limit established), required for DNA synthesis, methionine synthase homocysteine conversion, and myelin sheath maintenance.

View full Vitamin B12 (Cobalamin) spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Iron (Heme & Non-Heme)
Vitamin B12 (Cobalamin)
Nutrient Type
Essential Trace Mineral Water-Soluble Corrinoid Vitamin
Adult RDA / RDI
8 mg (Men) / 18 mg (Women 19–50) / 27 mg (Pregnancy) 2.4 µg / day (2.6µg pregnancy, 2.8µg lactation)
Tolerable Upper Limit (UL)
45 mg / day (Hemochromatosis / Fenton reaction oxidative stress) None Established (Extremely low toxicity)
Chemical Forms
Heme Iron (Fe2+ Porphyrin - Animal), Non-Heme Iron (Fe3+ Ferric / Fe2+ Ferrous - Plants/Supplements) Methylcobalamin (Active), Adenosylcobalamin (Active), Cyanocobalamin (Stable synthetic)
Primary Biological Function
Hemoglobin O2 transport, Myoglobin O2 storage, Cytochrome c electron transport, Catalase Methionine synthase cofactor, Methylmalonyl-CoA mutase cofactor, Myelin integrity, Erythropoiesis
Deficiency Condition
Microcytic Hypochromic Anemia, Severe fatigue, Restless legs syndrome, Pica Pernicious / Megaloblastic Anemia, Irreversible Neurological Peripheral Neuropathy
Top Whole Food Sources
Beef Liver, Oysters, Duck Breast, Beef Ribeye, Lentils, Spinach, Dark Chocolate Oysters, Beef Liver, Sardines, Salmon, Beef, Dairy, Eggs (Absent in unfortified plant foods)
Bioavailability Difference
Heme: 15–35% absorption (uninhibited); Non-Heme: 2–20% (inhibited by phytates/calcium, boosted by Vitamin C) —
Absorption Mechanism
— Requires Gastric Acid, R-Protein, and Intrinsic Factor (IF) via Ileal Cubam receptors

Other Alternatives to Compare

Compare Iron (Heme & Non-Heme) vs. Calcium (Elemental Ca) → Compare Iron (Heme & Non-Heme) vs. Iodine (Elemental I) → Compare Iron (Heme & Non-Heme) vs. Magnesium (Elemental Mg) → Compare Iron (Heme & Non-Heme) vs. Potassium (Elemental K) → Compare Iron (Heme & Non-Heme) vs. Selenium (Elemental Se) → Compare Iron (Heme & Non-Heme) vs. Sodium (Elemental Na) → Compare Iron (Heme & Non-Heme) vs. Vitamin A (Retinol & Beta-Carotene) → Compare Iron (Heme & Non-Heme) vs. Vitamin B1 (Thiamine) → Compare Iron (Heme & Non-Heme) vs. Vitamin B2 (Riboflavin) → Compare Iron (Heme & Non-Heme) vs. Vitamin B3 (Niacin / Nicotinic Acid & Nicotinamide) → Compare Iron (Heme & Non-Heme) vs. Vitamin B5 (Pantothenic Acid) → Compare Iron (Heme & Non-Heme) vs. Vitamin B6 (Pyridoxal 5'-Phosphate / PLP) → Compare Iron (Heme & Non-Heme) vs. Vitamin B7 (Biotin / Vitamin H) → Compare Iron (Heme & Non-Heme) vs. Vitamin B9 (Folate & Folic Acid) → Compare Iron (Heme & Non-Heme) vs. Vitamin C (L-Ascorbic Acid) → Compare Iron (Heme & Non-Heme) vs. Vitamin D3 (Cholecalciferol) → Compare Iron (Heme & Non-Heme) vs. Vitamin E (d-Alpha-Tocopherol) → Compare Iron (Heme & Non-Heme) vs. Vitamin K1 (Phylloquinone) → Compare Iron (Heme & Non-Heme) vs. Zinc (Elemental Zn) →