Iodine supplements can interact negatively with some medications. For example,
• High doses of iodine react negatively with anti-thyroid medications such as methimazole that treats hyperthyroidism. The combination can cause the production of insufficient thyroid hormones.
• Potassium iodide in combination with ACE inhibitors for high blood pressure can raise the level of potassium in your blood to harmful levels.
• Potassium iodide in combination with diuretics can make your potassium levels too high.
You should consult your pharmacist about any drugs you are currently taking before taking iodine supplements.
Can you get too much iodine?
Research has studied the effects of too much iodine intake. Most healthy people can tolerate high iodine intakes. But others may react poorly including hyperthyroidism, hypothyroidism, goiter, or thyroid autoimmunity.
Some studies show that excessive intakes of iodine can have the reverse effect of iodine deficiency – including elevated TSH levels and hypothyroidism. That’s because in susceptible individuals excess iodine can inhibit thyroid hormone systhesis and thereby elevate TSH stimulation.
It has also been shown that excessive iodine intakes cause thyroiditis and thyroid papillary cancer. However, cases of iodine poisoning are rare.
Other studies showed that too much iodine can be life-threatening to someone with preexisting thyroid disease if it induces hyperthyroidism.
A notable finding in a 2017 study was that excess iodine intake had an unfavorable stimulation of unhealthy activity in breast cancer cells. It also observed that thyroid related diseases have been increasing since iodized salt was mandated in 1997.
The recommended maximum daily iodine intake from all sources are
• Birth to 12 mos ……………..N/A
• Children 1 to 3 yrs………… 200 mcg
• Children 4 to 8 yrs…..……. 300 mcg
• Children 9 to 13 yrs………..600 mcg
• Teens 14 to 18 yrs………… 900 msg
• Adults ……………………..1,100 mcg
The U.S. decline in iodine sufficiency observed over the past five decades would suggest that Americans’ natural dietary habits are not sustaining their required iodine levels.
While certain precautions must be observed, we are increasingly turning to iodine dietary supplements. That should be encouraged with frequent monitoring to prevent excess iodine intake.