Oral iodized oil for correcting iodine deficiency: optimal dosing and outcome indicator selection.

Abstract

Oral iodized oil is the major alternative to iodized salt for correcting endemic iodine deficiency. This study responds to a need for better guidelines in its use. Schoolchildren, aged 6-11 yr, from a severely iodine-deficient area of Algeria received iodized poppy seed oil (Lipiodol) in a single oral dose containing 120, 240, 480, or 960 mg iodine (groups A-D) or in an im injection of 480 mg iodine (group E). Thyroid volume by ultrasonography had not changed 395 days after treatment in groups A, B, and C, had decreased in groups D and E. Urinary iodine concentration rose rapidly from an initial median of 0.21 mumol/L, but fell below 0.79 mumol/L (the currently accepted level for indicating iodine deficiency) by 150 days for groups A and B, and by 395 days for groups C and D. Median serum TSH and T4 levels were normal before and after treatment, whereas high initial serum thyroglobulin values decreased in all groups after iodized oil treatment. For correcting iodine deficiency in children, we recommend single oral doses of Lipiodol containing 240 mg iodine for 6-month coverage or 480 mg for 12 months. These doses may not completely sustain iodine sufficiency, but will prevent the worst of the iodine deficiency disorders. Additionally, we conclude that the urinary iodine concentration is the most useful epidemiological indicator for assessing current iodine status, and thyroid volume and serum thyroglobulin levels are the best markers for assessing chronic effects.

Iodine Deficiency in the World: Where Do we Stand at the Turn of the Century?

“…Goiter prevalence decreased rapidly and thyroid function reverted to normal and remained so for up to 7 years after injections of iodized oil and for up to 1 to 2 years after oral administration (47)(48)(49)(50)(51)(52)(53). Key factors in this success were normalization of the thyroid's iodine stores (48) and the level of iodization of thyroglobulin, the determining factor in impairment of thyroid function (36).…”

Doubling in the use of thyroid hormone replacement therapy in Denmark: association to iodization of salt?

“…However, only few studies have been made on the consequences of increasing the iodine intake in a population in relation to correction of iodine deficiency to optimal iodine nutrition. Some of these studies have found an association between the increase in iodine intake and an increase in the incidence of hypothyroidism [4][5][6], but not all studies have found this association [7,8]. The mechanism behind the effect could be an inhibitory effect of iodine on the thyroid [9], or that iodine induces autoimmunity in genetically predisposed persons [10,11].…”

Assessment of Urinary Iodine Excretion Among Normal Kuwaiti Adults

“…In a more recent 5-year Brazilian study, it has been reported that excessive iodine intake may have increased the prevalence of TAA 5.6 times and hypothyroidism 6.6 times when compared with patients from low iodine intake area [29]. This association may be due to iodine-induced increase in the immunogenicity of the thyroglobulin molecule [30,31]. However, some other studies have failed to find a correlation between iodine intake and the prevalence of TAA which could not support the notion that excessive iodine intake may not be the only factor to cause TAA [31][32][33][34].…”

“…This association may be due to iodine-induced increase in the immunogenicity of the thyroglobulin molecule [30,31]. However, some other studies have failed to find a correlation between iodine intake and the prevalence of TAA which could not support the notion that excessive iodine intake may not be the only factor to cause TAA [31][32][33][34]. Moreover, a recent report by Zeitlin et al [35] indicated that 50% of patients with TAA have a family history, suggesting that, under specific environmental conditions, individuals who are genetically predisposed may develop TAA.…”

“…Since the participants were not examined for anti-insulin antibodies, we could not rule out the possibility that some of the participants may have had type I diabetes. Furthermore, environmental factors are considered as an additional cause of TAA [31].…”