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

Iodine (Elemental I) vs. Vitamin D3 (Cholecalciferol)

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

Comparing:
Iodine (Elemental I)
Vitamin D3 (Cholecalciferol)
Iodine (Elemental I) →

Iodine is an essential halogen trace element required exclusively as an essential structural component of thyroid hormones thyroxine (T4) and triiodothyronine (T3), regulating metabolic rate, cellular respiration, and fetal neurodevelopment. Adult RDA is 150 µg, with an Upper Limit of 1,100 µg/day.

View full Iodine (Elemental I) spec sheet →
Vitamin D3 (Cholecalciferol) →

Vitamin D3 is a secosteroid prohormone synthesized endogenously in skin via solar UVB irradiation of 7-dehydrocholesterol. Adult RDA is 600–800 IU (15–20µg), with a Tolerable Upper Limit of 4,000 IU (100µg)/day, regulating systemic calcium absorption and immune gene expression.

View full Vitamin D3 (Cholecalciferol) spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Iodine (Elemental I)
Vitamin D3 (Cholecalciferol)
Nutrient Type
Essential Trace Halogen Element Fat-Soluble Secosteroid Prohormone
Adult RDA / RDI
150 µg / day (220 µg pregnancy / 290 µg lactation) 600 – 800 IU / day (15 – 20 µg)
Tolerable Upper Limit (UL)
1,100 µg / day (Avoid Wolff-Chaikoff thyroid autoregulatory shutdown) 4,000 IU / day (100 µg) (Endocrine Society: up to 10,000 IU safe)
Chemical Forms
Iodide (I- / Potassium Iodide KI, Potassium Iodate KIO3 in iodized salt), Molecular Iodine Cholecalciferol (D3 - Animal/Lichen), Ergocalciferol (D2 - Fungi)
Primary Biological Function
Constituent of Thyroxine (T4, 4 iodine atoms / 65% by weight) and Triiodothyronine (T3, 3 iodine atoms / 59% by weight) Calcitriol receptor (VDR) activation, intestinal calcium/phosphorus absorption, antimicrobial peptide synthesis
Deficiency Condition
Endemic Goiter (Compensatory thyroid enlargement), Congenital Hypothyroidism / Cretinism (Permanent neurodevelopmental impairment), Maternal miscarriages Rickets (children), Osteomalacia (adults), Immune dysregulation
Top Whole Food Sources
Kombu Kelp, Nori Seaweed, Atlantic Cod, Eastern Oysters, Iodized Table Salt, Greek Yogurt, Dairy Milk, Eggs Sunlight UVB, Atlantic Salmon, Sardines, Egg Yolk, Fortified Milk
Iodized Salt Public Health Impact
Universal salt iodization (45–75 mg KI / kg salt) is hailed as one of the greatest global public health achievements, eradicating cretinism worldwide —
Target Serum 25(OH)D Level
— 30 – 50 ng / mL (75 – 125 nmol / L)

Other Alternatives to Compare

Compare Iodine (Elemental I) vs. Calcium (Elemental Ca) → Compare Iodine (Elemental I) vs. Iron (Heme & Non-Heme) → Compare Iodine (Elemental I) vs. Magnesium (Elemental Mg) → Compare Iodine (Elemental I) vs. Potassium (Elemental K) → Compare Iodine (Elemental I) vs. Selenium (Elemental Se) → Compare Iodine (Elemental I) vs. Sodium (Elemental Na) → Compare Iodine (Elemental I) vs. Vitamin A (Retinol & Beta-Carotene) → Compare Iodine (Elemental I) vs. Vitamin B1 (Thiamine) → Compare Iodine (Elemental I) vs. Vitamin B12 (Cobalamin) → Compare Iodine (Elemental I) vs. Vitamin B2 (Riboflavin) → Compare Iodine (Elemental I) vs. Vitamin B3 (Niacin / Nicotinic Acid & Nicotinamide) → Compare Iodine (Elemental I) vs. Vitamin B5 (Pantothenic Acid) → Compare Iodine (Elemental I) vs. Vitamin B6 (Pyridoxal 5'-Phosphate / PLP) → Compare Iodine (Elemental I) vs. Vitamin B7 (Biotin / Vitamin H) → Compare Iodine (Elemental I) vs. Vitamin B9 (Folate & Folic Acid) → Compare Iodine (Elemental I) vs. Vitamin C (L-Ascorbic Acid) → Compare Iodine (Elemental I) vs. Vitamin E (d-Alpha-Tocopherol) → Compare Iodine (Elemental I) vs. Vitamin K1 (Phylloquinone) → Compare Iodine (Elemental I) vs. Zinc (Elemental Zn) →