Levothyroxine with Kelp Interaction Details

An excess of iodine can also lead to Grave’s disease, thyroid cancer and toxic levels of thyroid hormones. Symptoms of iodine poisoning include abdominal pain, diarrhea, fever, lack of urination, seizures, shortness of breath, thirst and vomiting, per the HSPH. Iodine is an essential trace mineral; the body can’t produce it, so it has to come from your diet. Iodine isn’t the only culprit when it comes to toxicity, overdose, interactions and other adverse side effects of kelp supplements. It is commonly enjoyed sautéed, in salads or as a dried snack, and is also available as a dietary supplement that is often marketed as being good for the thyroid.

Upon admission, her serum thyroxine (T4) was 1.3 mcg/deciliter (dL), serum triiodothyronine (T3) was 47 nanograms (ng)/dL, and thyroid stimulating hormone (TSH) was 132 synthroid dangers microunits (microU)/mL. When seaweed was discontinued from her diet for 2 weeks, T4 rose to 6.3 mcg/dL, T3 rose to 133 ng/dL, and TSH decreased to 11 microU/mL. At 16 weeks, the patient’s blood test results reflected the significant impact sea kelp discontinuation had on her TSH.

Effects of kelp supplementation on thyroid function in euthyroid subjects

Iodine is an essential micronutrient which is crucial for normal thyroid function. When iodine intake fallsbelow the recommended level, the thyroid may not synthesize sufficient amounts of thyroid hormone. Worldwide,about 30% of the population, which is about 1,900 million people, has an inadequate iodine intake (1). ICCIDD recommended that iodizedsalt should contain 20–40 mg/kg (20–40 µg/g) of iodine in order to provide 150 µg/day of iodine, the recommendeddaily intake for an adult.

Treatment

It’s important to recognize that the high doses of iodine in kelp supplements and other dietary sources can throw your thyroid out of whack even if you don’t currently have thyroid issues. “Excess iodine can … lead to too much thyroid hormone production, causing hyperthyroidism,” warns the Harvard T.H. Chan School of Public Health (HSPH). “Sometimes even just a slight increase in dietary iodine above the RDA can cause iodine-induced hyperthyroidism in sensitive individuals.” Following the escape from the acute Wolff-Chaikoff effect, the biosynthesis of NIS can be shut down by a TSH-independent mechanism. D)Two cases of reversible hypothyroidism were reported in patients ingesting seaweed (kelp) daily containing 25.4 mg and 43.1 mg iodine, along with 2 cases of irreversible hypothyroidism in patients ingesting seaweed daily containing 15 mg and 20 mg iodine.

Iodide-induced goitre was first reported in the residents of the island of Hokkaido, Japan, termed “endemic coastal goitre” 44. Iodization of table salt in Denmark showed a decrease in goitre and hyperthyroidism, mainly toxic nodular goitre, but a small increase in hypothyroidism 45. An increased prevalence of papillary thyroid cancer has been reported in postpartum Japanese consuming daily seaweed dishes compared to those whose consumption was 2 days per week or less 46. The mechanism through which seaweed or high iodine levels might promote thyroid cancer remains unclear, but a role for iodine in suppressing miR-422a and thereby facilitating tumourogenesis by upregulating MAPK1 has been proposed 47. Although the ocean and its resident seaweed provide the greatest single store of iodine, consumption of seaweeds or seafoods in general do not for most populations provide the major dietary source of iodine.

• Iodine in sea water is mainly present as I− and IO3, with I− predominating in surface waters while IO3 forms the greatest proportion in deep water 27.
• However, recent studies from the author’s laboratory have shown that urinary iodine (UI) excretion in coastal areas did not differ substantially from their inland neighbours 13, 16.
• A 45-years-old woman presented to the outpatient clinic for mild anterior neck pain.
• You can click on the reference number within brackets ” to see what reference was utilized.
• Each sea kelp tablet contains 150 micrograms of iodine; therefore, 450 micrograms of iodine are being ingested daily by the patient.
• You can learn more about hyperthyroidism, hypothyroidism, thyroid functioning, diagnostic testing and thyroid treatment in our Guide to Thyroid Hormones.

Recommendations for thyroid hormone based on insufficient evidence, say clinical bodies

During the SMR, the pharmacist explained to the patient that weight loss would be a struggle with uncontrolled hypothyroidism. She was advised to continue with the same dosage of levothyroxine and to have a repeat thyroid profile in 8–12 weeks (although it had to take place in 16 weeks because the patient had travel plans). We have described a case of transient hyperthyroidism following the ingestion of kelp-containing tablets.

• O3 in the lower atmosphere (troposphere) is the product of the reaction of chemical pollutants with sunlight and is a strong reactive oxygen species whose removal by seaweed is beneficial to human respiratory health 67.
• Today, iodine deficiency is rare in the United States, says the Cleveland Clinic.
• Consuming seaweed alone or as a dietary supplement is unlikely to be harmful if taken occasionally (once or twice a week).
• Although the concentration of iodine in seawater is relatively low (approx. 58 µg/L) 26, its massive abundance makes it the major source of iodine on the planet.
• Attempting to self-treat with a kelp supplement may make existing thyroid conditions worse, or cause one where it didn’t previously exist.

Further analysis revealed normal thyroid function, so the hyperthyroidism reversed completely. “Both hyperthyroidism and hypothyroidism have been linked to too much kelp intake,” note researchers at the University of Rochester Medical Center. “This is due to its high amount of iodine. Abnormal thyroid function has also been linked directly to too much use of kelp supplements.”

The Dosage of Kelp for Thyroid Function

Kelp is a type of brown seaweed and is often found in dense, fixed areas called kelp beds or kelp forests. The patient’s symptoms are consistent with hypothyroidism but also overlap with her history of PTSD and fibromyalgia. During the appointment, her clinical observations are unremarkable, with normal oxygen saturation, pulse rate and blood pressure within normal limits and afebrile. The modest thyroid pain at palpation could suggest the occurrence of a subacute thyroiditis. However, thyroid pain at palpation is compatible with the fast thyroid enlargement. The ultrasound feature of ‘thyroid inferno’ is not typical of subacute thyroiditis, while it has been documented to occur after an excessive iodine load.

Many vulnerable groups where iodine requirement is increased such as pregnant mothers, their infants, vegans, or women of childbearing age continue to show deficits in iodine intake despite the availability of iodized salt 6, 7. Many commercial supplements containing iodine are available, but there is no recommendation for taking supplements even in countries such as Ireland and the UK where universal salt iodization is not practiced 14. According to the British Dietetic Association and the European Food Safety Authority (EFSA), the recommended daily intake of iodine is 150 micrograms in adults (increasing to 200 micrograms in pregnant or breastfeeding adults)​9​. Iodine is present in a range of foods and is particularly rich in dairy products, milk and fish. The concentration of iodine can vary within different seaweed products and can occasionally lead to excessive iodine intake.

“Even a small systematic increase in iodine supply can significantly increase the risk of thyroid disease. … The mechanism through which seaweed or high iodine levels might promote thyroid cancer remains unclear.” When it comes to eating kelp or taking kelp supplements, the iodine level that could cause overdose varies from person to person, depending on individual physiological factors and how much iodine is consumed via other iodine sources such as iodized salt. When we started powdered kelp at 1.6–2 g/d in 2 cases, their UICs were too high (1,380 µg/l in case 4, 560 µg/lin case 5, not presenting in Table 2).