Levothyroxine with Kelp Interaction Details

Quantities of 500micrograms to 1mg daily probably have no untoward effects on thyroid function in most cases. However, there is potential for the development of thyroid disorders if more than 150micrograms of iodine per day are ingested. In Japan, where high amounts of kelp and other seaweed are consumed, some people exhibit a type of thyroid blockage that causes a diet-induced goiter.

If you suspect you have a thyroid disorder, visit your doctor to have it definitively diagnosed. The most common symptoms of thyroid disorders, like changes in energy levels, weight gain or loss and skin changes may also be caused by a number of other disorders, including simple things like nutritional deficiencies. If your thyroid isn’t functioning properly, your doctor will determine the cause and prescribe the appropriate medication. Attempting to self-treat with a kelp supplement may make existing thyroid conditions worse, or cause one where it didn’t previously exist.

Kelp Supplement Could Make Thyroid Problem Worse:

Of note was no clinical side effect was observed during treatment by powderedkelp, except high UIC in synthroid pneumonic two patients as described above. We believe powdered kelp is one of the best treatmentsfor SMID with ID in Japan. Patients on long term enteral nutrition (EN) develop ID because of the low iodine content of EN formula.

Slowed thyroid function

The relative iodine sufficiency of populations is routinely examined by measuring UI excretion. Although assessment of UI provides a useful index of population iodine intake, the value obtained reflects recent dietary intake and is not useful for determining the long-term iodine status of an individual. Another possible pitfall in investigating iodine sufficiency is that population iodine status is commonly established by measuring urine samples from school-aged children.

Kelp Safety, Iodine Overdose and Thyroid Health Effects

• We’re glad you worked with your doctor and got good results, but we don’t generally recommend this approach.
• During the appointment, her clinical observations are unremarkable, with normal oxygen saturation, pulse rate and blood pressure within normal limits and afebrile.
• If the thyroid starts producing too much hormone, it’s a condition known as hyperthyroidism.
• Examples of these nutraceuticals include sea kelp, carnitine, inositol, melatonin and resveratrol​5​.
• For these reasons, taking kelp supplements specifically for their iodine content is considered unnecessary.
• We describe a case of dysfunction following the ingestion of a marketed diet containing natural components, including kelp, a type of seaweed known for its rich iodine content and Lentinus edodes also known as ‘shiitake mushroom’ or ‘black forest mushroom’.

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 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.

Sources of Food Iodine Intake

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.

Recently, TheJapanese Society for Pediatric Endocrinology (JSPE) issued a special request for some company (e.g., Abbott,Otsuka) to add iodine to its EN formula. In this case report, the consumption of sea kelp and consequent excessive daily intake of iodine proved to negatively impact the patient’s thyroid function, resulting in overt hypothyroidism. Hypertensive and obese patient, without previous thyroid disease, presented with transient hyperthyroidism at 3 months following ingestion of tablets containing kelp seaweed.

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.

Table 2.  Thyroid function and UIC before/after iodine supplementation.

Studies linking seaweed intake to breast cancer prevalence are discussed as is the role of gaseous iodine released from seaweeds influencing weather patterns and contributing to iodine intake in coastal populations. The principal causes of hyperthyroidism are Graves’ disease, toxic thyroid adenoma and toxic multinodular goiter. Endocrine tests revealed normal range of thyroid hormones and thyroid stimulating hormone (TSH) at 1, 2, 3, 6, and 12 months following completion of Methimazole treatment (Table 2). In addition, the thyroid was further monitored, and the endocrine tests showed normal thyroid function, so the hyperthyroidism reversed completely.

Excessive salt intake

The dietary preferences of vegetarians and vegans frequently result in iodine deficiency 38, 39. Iodine-supplemented milk alternatives may be available, but as with other supplements consumed by vegans, seaweed additives made from brown seaweeds may contain excess iodine 25. Use of iodized salt with or without appropriate supplements to achieve adult or pregnancy daily (150 or 250 μg) intakes in vegans and non-vegans alike is recommended 37, 38, 39. Complementary medications and herbal medicine for weight loss have become very popular. We report a case of thyroid dysfunction following the ingestion of a kelp-containing marketed diet in a 45-year-old woman with no previous thyroid disease.