Potassium iodide is marketed as a source of iodine, not a source of potassium. If you take potassium iodide, you don't need additional iodine supplements. Iodine deficiencies are common in the undeveloped world where people are not exposed regularly to iodized salt. Such deficiencies can cause goiter, mental retardation, hypothyroidism and other disorders.
Iodine Supplements
Iodine supplements are usually made from potassium iodide, or less commonly, potassium iodate. Both compounds are salts that contain the iodine atom. According to the World Health Organization, potassium iodide is the preferred supplement because the iodate form can irritate the digestive system. The shelf life of both compounds is roughly the same, although potassium iodate might hold up better when subjected to hot, humid conditions.
Thyroid Support
Cellular metabolism refers to how effectively a cell uses glucose. This process is controlled by the thyroid hormones thyroxine, or T4, and triiodothyronine, or T3. Iodine is essential for making these hormones. Every cell in the body depends upon T3 and T4 to regulate the cell's metabolism. Thyroid cells are the only cells in the body that can absorb iodine.
Sources
The risk of iodine deficiency is substantially lower if you live in the industrialized world where you are regularly exposed to iodized salt. Other sources include saltwater fish and seaweed. Milk products are also good sources because iodine added to animal feed appears in the animals' milk. Dairy cattle that are exclusively grass-fed may provide less iodine than those that eat prepared feeds.
Use in Disasters
Nuclear reactors release a form of radioactive iodine after accidents. People who ingest this radioactive iodine are at a higher risk for thyroid cancers. In the 15 years following the disaster at Chernobyl, the World Health Organization reported more than 1,000 cases of thyroid cancer that were "most probably solely attributable" to radioactive releases. This can be prevented by taking potassium iodide 48 hours before or 8 hours after the radioactive releases, which is why the Japanese government distributed units of iodine following the Fukushima disaster.
References
- World Health Organization; Guidelines for Iodine. Prophylaxis following Nuclear Accidents; 1999
- Linus Pauling Institute; Iodine; Jane Higdon, Ph.D.; April, 2003
- "Health Physics"; Potassium Iodate and its Comparison to Potassium Iodide as a Blocker of 131I Uptake by the Thyroid in Rats; D. Pahuja, et al.; November 1993
- Estrella Mountain Community College: Cellular Metabolism and Fermentation
- Reuters; Japan distributes iodine to evacuation centres-IAEA; March 14, 2011
