Side-by-Side Comparison
Essential Vitamins & Minerals
Calcium (Elemental Ca) vs. Iron (Heme & Non-Heme)
Comparing 2 standards across 9 specifications. 9 key differences identified.
Comparing:
Calcium (Elemental Ca)
Iron (Heme & Non-Heme)
Calcium is the most abundant mineral in the human body (1.0–1.2 kg), with 99% sequestered in hydroxyapatite bone lattice and 1% tightly regulated at 8.5–10.5 mg/dL serum for cardiac contractility, nerve signaling, and blood coagulation. Adult RDA is 1,000–1,200 mg/day.
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.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nutrient Type
|
Essential Macromineral | Essential Trace Mineral |
|
Adult RDA / RDI
|
1,000 mg / day (Men 19–70, Women 19–50) / 1,200 mg (Women 51+, Men 71+) | 8 mg (Men) / 18 mg (Women 19–50) / 27 mg (Pregnancy) |
|
Tolerable Upper Limit (UL)
|
2,500 mg / day (Adults 19–50) / 2,000 mg / day (Adults 51+) (Avoid nephrolithiasis / vascular calcification) | 45 mg / day (Hemochromatosis / Fenton reaction oxidative stress) |
|
Chemical Forms
|
Calcium Carbonate (40% elemental Ca / requires stomach acid), Calcium Citrate (21% elemental Ca / acid-independent), Hydroxyapatite | Heme Iron (Fe2+ Porphyrin - Animal), Non-Heme Iron (Fe3+ Ferric / Fe2+ Ferrous - Plants/Supplements) |
|
Primary Biological Function
|
Hydroxyapatite bone/dental structure [Ca10(PO4)6(OH)2], Troponin-C actin-myosin muscle contraction, Factor IV blood clotting cascade, Exocytosis neurotransmitter release | Hemoglobin O2 transport, Myoglobin O2 storage, Cytochrome c electron transport, Catalase |
|
Deficiency Condition
|
Osteoporosis, Osteopenia, Rickets (children), Tetany (Trousseau's and Chvostek's signs of hypocalcemia) | Microcytic Hypochromic Anemia, Severe fatigue, Restless legs syndrome, Pica |
|
Top Whole Food Sources
|
Parmigiano-Reggiano, Sharp Cheddar, Whole Milk, Sardines with bones, Kale, Tofu (Calcium-set), Fortified Plant Milk | Beef Liver, Oysters, Duck Breast, Beef Ribeye, Lentils, Spinach, Dark Chocolate |
|
Parathyroid Hormone (PTH) Homeostasis
|
Serum Ca2+ drop triggers PTH secretion, stimulating renal 1-alpha-hydroxylase to produce active Calcitriol (1,25-OH-D3) and osteoclast bone resorption | — |
|
Bioavailability Difference
|
— | Heme: 15–35% absorption (uninhibited); Non-Heme: 2–20% (inhibited by phytates/calcium, boosted by Vitamin C) |
Other Alternatives to Compare
Compare Calcium (Elemental Ca) vs. Iodine (Elemental I) →
Compare Calcium (Elemental Ca) vs. Magnesium (Elemental Mg) →
Compare Calcium (Elemental Ca) vs. Potassium (Elemental K) →
Compare Calcium (Elemental Ca) vs. Selenium (Elemental Se) →
Compare Calcium (Elemental Ca) vs. Sodium (Elemental Na) →
Compare Calcium (Elemental Ca) vs. Vitamin A (Retinol & Beta-Carotene) →
Compare Calcium (Elemental Ca) vs. Vitamin B1 (Thiamine) →
Compare Calcium (Elemental Ca) vs. Vitamin B12 (Cobalamin) →
Compare Calcium (Elemental Ca) vs. Vitamin B2 (Riboflavin) →
Compare Calcium (Elemental Ca) vs. Vitamin B3 (Niacin / Nicotinic Acid & Nicotinamide) →
Compare Calcium (Elemental Ca) vs. Vitamin B5 (Pantothenic Acid) →
Compare Calcium (Elemental Ca) vs. Vitamin B6 (Pyridoxal 5'-Phosphate / PLP) →
Compare Calcium (Elemental Ca) vs. Vitamin B7 (Biotin / Vitamin H) →
Compare Calcium (Elemental Ca) vs. Vitamin B9 (Folate & Folic Acid) →
Compare Calcium (Elemental Ca) vs. Vitamin C (L-Ascorbic Acid) →
Compare Calcium (Elemental Ca) vs. Vitamin D3 (Cholecalciferol) →
Compare Calcium (Elemental Ca) vs. Vitamin E (d-Alpha-Tocopherol) →
Compare Calcium (Elemental Ca) vs. Vitamin K1 (Phylloquinone) →
Compare Calcium (Elemental Ca) vs. Zinc (Elemental Zn) →