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

Iodine (Elemental I) vs. Vitamin E (d-Alpha-Tocopherol)

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

Comparing:
Iodine (Elemental I)
Vitamin E (d-Alpha-Tocopherol)

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 E is the principal fat-soluble peroxyl radical-scavenging antioxidant protecting cellular polyunsaturated membrane phospholipids. Adult RDA is 15 mg (22.4 IU) of d-alpha-tocopherol, with a Tolerable Upper Limit of 1,000 mg (1,500 IU)/day.

View full Vitamin E (d-Alpha-Tocopherol) spec sheet →

Specification Comparison Table

9 Parameters
Parameter / Spec
Nutrient Type
Essential Trace Halogen Element Fat-Soluble Chromanol Lipophilic Vitamin
Adult RDA / RDI
150 µg / day (220 µg pregnancy / 290 µg lactation) 15 mg / day (22.4 IU) of 2R-alpha-tocopherol
Tolerable Upper Limit (UL)
1,100 µg / day (Avoid Wolff-Chaikoff thyroid autoregulatory shutdown) 1,000 mg / day (1,500 IU synthetic) (Excess impairs Vitamin K clotting cascade)
Chemical Forms
Iodide (I- / Potassium Iodide KI, Potassium Iodate KIO3 in iodized salt), Molecular Iodine RRR-alpha-Tocopherol (Natural d-alpha), all-rac-alpha-Tocopherol (Synthetic dl-alpha), Gamma/Delta-Tocopherols
Primary Biological Function
Constituent of Thyroxine (T4, 4 iodine atoms / 65% by weight) and Triiodothyronine (T3, 3 iodine atoms / 59% by weight) Breaks lipid peroxidation chain in PUFA cell membranes, protects LDL from oxidative modification, maintains erythrocyte membrane integrity
Deficiency Condition
Endemic Goiter (Compensatory thyroid enlargement), Congenital Hypothyroidism / Cretinism (Permanent neurodevelopmental impairment), Maternal miscarriages Hemolytic anemia, Spinocerebellar ataxia, Peripheral neuropathy, Loss of vibratory/proprioceptive sense
Top Whole Food Sources
Kombu Kelp, Nori Seaweed, Atlantic Cod, Eastern Oysters, Iodized Table Salt, Greek Yogurt, Dairy Milk, Eggs Wheat Germ Oil, Sunflower Seeds, Raw Almonds, Hazelnuts, Sunflower Oil, Spinach, Hass Avocado
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
Hepatic Alpha-TTP Specificity
The liver secretes only alpha-tocopherol into VLDL via Alpha-Tocopherol Transfer Protein (alpha-TTP); other tocopherols are degraded in bile