Key Advantages

  • Assessment of essential Iodine/Iodide excretion
  • Variable urine collection periods
  • Challenged & Unchallenged options
  • State-of-the-art ICP-MS elemental analysis

Introduction

Iodine/Iodide is an essential element that is pivotal to normal function of the thyroid gland and the health and integrity of breast tissue.   Iodine/Iodide intake has decreased significantly over the past thirty years and consequentially clinical symptoms have become increasingly apparent.  Current Iodine/Iodide supply can be readily assessed by analysis of urinary iodide excretion.

What Tissues Need Iodine?

Specific tissues in the body utilise iodide and iodine. Adequate iodine status is essential for the production of normal levels of thyroid hormones and the integrity of thyroid and mammary glands. Iodide, the reduced form of iodine, is highly concentrated in the thyroid gland where it is incorporated into thyroid hormones.   Thyroid hormones regulate growth and metabolic rate, body heat and energy production, and neuronal and sexual development. Iodine is concentrated in the breasts where it is associated with protection against Fibrocystic Breast Disease and Cancer. Sub-clinical iodine/iodide deficiency has been associated with impaired mental function and reduced energy production to hypothyroidism.

What Valid Testing Options Exist?

Doctor’s Data, Inc. offers three urine iodine report formats and collection options to allow the practitioner a wide range of assessment options to fit every individual patient’s needs.

Traditionally, the level of urinary iodine from a twenty-four hour collection has been utilised to assess iodine intake.   Alternatively, in situations where patient compliance is difficult, a random urine collection, preferably the first morning void, provides indication of current iodine intake, when expressed per mg creatinine. The urinary iodine value presented on both report formats represents iodine plus iodide oxidised to free iodine.  Patient results are plotted against reference values.   Normative values for urinary iodine have been evaluated in large population studies in the western population over the past thirty-five years.

Evolving the Science

In more recent times a “24-hour iodine/iodide load test” has become a useful analysis for practitioners. In order to calculate the rate of excretion vs retention (assess iodine sufficiency), Doctors Data suggests an oral loading dose of iodine/iodide be ingested and all collected for the subsequent 24 hours.

The test is based on the concept that the body has specific and saturable mechanisms to take up iodine/iodide.  When maximal retention is attained, the percentage of an iodine/iodide load that is retained decreases and the percentage urinary excretion increases. The percentage excretion is calculated by dividing the patient’s mg/24-hour iodine results by the oral iodine/iodide dosage (mg) provided on the requisition form by the practitioner, then multiplied by 100.  The iodine excretion value represents free iodine plus iodide oxidised to free iodine.

Iodine is essential for:

  • Thyroid Function
  • And therefore overall Endocrine function
  • And therefore all body systems (eg. metabolism)
  • The health of breast tissue
  • Neurological development
Iodine skin ‘patch testing’ has been shown not to provide a valid method of testing Iodine status. Skin evaporation was demonstrated as a function more of temperature, humidity and other unrelated factors rather than Iodine utilisation. Therefore urine Iodine testing is advised as a more evidence-based means of Iodine assessment for healthcare practitioners.

Note: See Urine Halides – Pre and Post Loading test for a review of urine iodine testing that includes assessment of the other ‘Toxic’ halogens (fluoride and Bromide) that might be obstructing its utilisation in some cases.

Resources
References

Nyiri, W., Jannitti, M., About the fate of free iodine upon application to the unbroken animal skin. An experimental study. J. Pharmacd. Exp. Ther., 45:85-107, 1932.
Miller, K.L., Coen, P.E., White, W.J., et al, Effectiveness of Skin Absorption of Tincture of I in Blocking Radioiodine from the Human Thyroid Gland. Health Physics, 56:911-914, 1989.