Iodine (Elemental I) vs. Vitamin B12 (Cobalamin)
Comparing 2 standards across 9 specifications. 9 key differences identified.
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.
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.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nutrient Type
|
Essential Trace Halogen Element | Water-Soluble Corrinoid Vitamin |
|
Adult RDA / RDI
|
150 µg / day (220 µg pregnancy / 290 µg lactation) | 2.4 µg / day (2.6µg pregnancy, 2.8µg lactation) |
|
Tolerable Upper Limit (UL)
|
1,100 µg / day (Avoid Wolff-Chaikoff thyroid autoregulatory shutdown) | None Established (Extremely low toxicity) |
|
Chemical Forms
|
Iodide (I- / Potassium Iodide KI, Potassium Iodate KIO3 in iodized salt), Molecular Iodine | Methylcobalamin (Active), Adenosylcobalamin (Active), Cyanocobalamin (Stable synthetic) |
|
Primary Biological Function
|
Constituent of Thyroxine (T4, 4 iodine atoms / 65% by weight) and Triiodothyronine (T3, 3 iodine atoms / 59% by weight) | Methionine synthase cofactor, Methylmalonyl-CoA mutase cofactor, Myelin integrity, Erythropoiesis |
|
Deficiency Condition
|
Endemic Goiter (Compensatory thyroid enlargement), Congenital Hypothyroidism / Cretinism (Permanent neurodevelopmental impairment), Maternal miscarriages | Pernicious / Megaloblastic Anemia, Irreversible Neurological Peripheral Neuropathy |
|
Top Whole Food Sources
|
Kombu Kelp, Nori Seaweed, Atlantic Cod, Eastern Oysters, Iodized Table Salt, Greek Yogurt, Dairy Milk, Eggs | Oysters, Beef Liver, Sardines, Salmon, Beef, Dairy, Eggs (Absent in unfortified plant foods) |
|
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 | — |
|
Absorption Mechanism
|
— | Requires Gastric Acid, R-Protein, and Intrinsic Factor (IF) via Ileal Cubam receptors |