Nutr Res Pract.  2016 Apr;10(2):167-174. 10.4162/nrp.2016.10.2.167.

Dietary evaluation of a low-iodine diet in Korean thyroid cancer patients preparing for radioactive iodine therapy in an iodine-rich region

• Ju DL
• Park YJ
• Paik HY
• Kim MJ
• Park S
• Jung KY
• Kim TH
• Choi HS
• Song YJ

• KMID: 2313914
• DOI: http://doi.org/10.4162/nrp.2016.10.2.167

Abstract

BACKGROUND/OBJECTIVES
Despite the importance of a low-iodine diet (LID) for thyroid cancer patients preparing for radioactive iodine (RAI) therapy, few studies have evaluated dietary intake during LID. This study evaluated the amount of dietary iodine intake and its major food sources during a typical diet and during LID periods for thyroid cancer patients preparing for RAI therapy, and examined how the type of nutrition education of LID affects iodine intake.
SUBJECTS/METHODS
A total of 92 differentiated thyroid cancer patients with total thyroidectomy were enrolled from Seoul National University Hospital. All subjects completed three days of dietary records during usual and low-iodine diets before 131I administration.
RESULTS
The median iodine intake was 290 µg/day on the usual diet and 63.2 µg/day on the LID. The major food groups during the usual diet were seaweed, salted vegetables, fish, milk, and dairy products and the consumption of these foods decreased significantly during LID. The mean energy intake on the LID was 1,325 kcal, which was 446 kcal lower than on the usual diet (1,771 kcal). By avoiding iodine, the intake of most other nutrients, including sodium, was significantly reduced during LID (P < 0.005). Regarding nutritional education, intensive education was more effective than a simple education at reducing iodine intake.
CONCLUSION
Iodine intake for thyroid cancer patients was significantly reduced during LID and was within the recommended amount. However, the intake of most other nutrients and calories was also reduced. Future studies are needed to develop a practical dietary protocol for a LID in Korean patients.

Keyword

Low-iodine diet; thyroid cancer; radioactive iodine therapy; iodine intake; dietary record

MeSH Terms

Dairy Products
Diet Records
Diet*
Education
Energy Intake
Humans
Iodine*
Milk
Seaweed
Seoul
Sodium
Thyroid Gland*
Thyroid Neoplasms*
Thyroidectomy
Vegetables
Iodine
Sodium

Figure

• 

  Fig. 1 The iodine intake and urinary iodine during usual and low-iodine diet periods among Korean thyroid cancer patients. (a) Iodine intake, (b) Urinary iodine/Creatinine ratio in spot-urine. Q1: 25th percentile, Q3: 75th percentile, Box: Q3-Q1 (Inter-quartile range), ⋄: mean, ▪: extreme value. ▪: 2 extreme values are clipped on the box plot (a). ▪: 3 extreme values are clipped on the box plot (b). †P value obtained using a paired t-test to compare the usual and low-iodine diets.

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