Low Iodine Diet (LID)
The TCC version of the Low Iodine Diet has been officially endorsed by
and is "PEN Approved" *
* Practice-based Evidence in Nutrition (PEN) is a project of the Dietitians of Canada.
An important way to maximize absorption of radioactive iodine (RAI) is by reducing the dietary intake of iodine prior to the use of RAI. This preparation can be achieved through a Low Iodine Diet (LID).
The LID is a special diet used by patients who are going to be treated and/or scanned with radioactive iodine (RAI). Unfortunately there is a lot of variation and misinformation in prescribed LIDs from place to place in Canada and elsewhere. As well, what may apply in some countries does not necessarily apply to Canadians due to differences in our food supply and packaging regulations.
The TCC LID includes: basic LID information, the diet, a shopping list and menu samples.
Order your own FREE copy.
TCC welcomes you to view the TCC Low Iodine Diet References, Writers and Reviewers (updated 2011).
To address questions from professionals (dietitians, nutritionists, MDs) and from patients, TCC developed a Frequently Asked Questions about the LID.
The following information is offered as a basic outline for your convenience. We highly recommend that patients download or request a hard copy of the LID from TCC, which offers much more detail.
Quick LID Facts
- The LID is a low iodine diet, usually interpreted as below 50mcg of iodine per day. Iodine is naturally occurring in many foods and added to table salt in Canada.
- Foods that are most highly laden with iodine and should be avoided are: table salt, dairy products, egg yolks and sea foods of all types. Soy is also restricted due to its interference with RAI uptake.
- The LID is normally prescribed for two weeks before the RAI treatment. The days closest to the RAI treatment are the most important ones in terms of restricting one’s diet. As the LID is not a nutritionally rounded diet, TCC does not recommend patients be on it more than 2 weeks pre-RAI. A recent study indicates no benefit to being on LID more than 2 weeks. View here.
- Patients with good general health and normal metabolisms are advised to stay on the LID 48 hours after RAI treatment to ensure that natural iodine does not interfere with the treatment iodine. Other patients may require a longer period of time on the LID post-treatment. Note that in most cases, patients in hospital isolation are not provided with LID meals. It is advisable for patients to bring some LID-safe foods with them if they will have a period of hospital isolation.
More Studies Regarding the Low Iodine Diet
Two weeks on the LID equivalent to 3 weeks http://www.thyroidcancercanada.org/userfiles/files/Two_vs_Three_Weeks_LID.pdf
Two week LID is necessary for RAI prep http://www.thyroidcancercanada.org/userfiles/files/LID_Park_study_2004%281%29.pdf
Sawka et al: Dietary Iodine Restriction in Preparation for Radioactive Iodine Treatment or Scanning in Well-Differentiated Thyroid Cancer: A Systematic Review, Thyroid. 2010 October; 20(10): 1129–1138. Systematic Review of literature regarding LID http://www.thyroidcancercanada.org/userfiles/files/Sawka_LID_studies.pdf
Pluijmen et al: Effects of low-iodide diet on postsurgical radioiodide ablation therapy in patients with differentiated thyroid carcinoma. Clinical Endocrinology, Volume 58, Issue 4, pages 428–435, April 2003