FDM Training Program; Mod 7 * The Biochemical Effects of Iodine Wayne L. Sodano, D.C., D.A.B.C.I. & Ron Grisanti, D.C., D.A.B.C.O., M.S.

Transcription

1 Functional Diagnostic Medicine Training Program Module 7 * FMDT 561D The Biochemical Effects of Iodine (Review of Nutrient Element Status Testing) By Wayne L. Sodano, D.C., D.A.B.C.I. & Ron Grisanti, D.C., D.A.B.C.O., M.S. Various combinations of factors can add up to elemental deficiency, as illustrated here for iron. Diet Poor Iron Absorption Loss of Blood Increased Physiologic Requirements Low Iron Supply + High Iron Demand Iron Deficiency Ref: Laboratory Evaluations for Integrative & Functional Medicine; 2 nd ed; Lord & Bralley The Effect of Iron Deficiency on Iodine and Thyroid Function Studies in human have shown that moderate-tosevere iron deficiency significantly lowers both T3 and T4 (although T3 to a greater extent) and reduces TSH responsiveness. This is thought to be due to impaired thyroid peroxidase activity. 2 1

2 Macro minerals are present in total-body content of tens or hundreds of grams Phosphorus Magnesium Calcium Sodium Potassium Chloride (Sodium, potassium, and chloride are classified as electrolytes because of their roles in maintaining ionic equilibria in physiological systems.) Thirteen trace elements are currently known to be nutritionally essential for human health. (micrograms per gram of tissue) Iron, copper, zinc, iodine, selenium, boron, cobalt, chromium, molybdenum, manganese, vanadium, silicon, and nickel A defining characteristic of a trace element is that a very small amount is necessary for proper function of the whole organism. Major Roles of Essential Elements In Biological Systems Electron acceptors in oxidative/reductive homeodynamics Enzyme cofactors Crystalline structures (bone) Ionic migrations necessary for nerve signal transmission or cell regulatory responses 2

3 Effects of Elemental Deficiency or Excess Therapeutic Range Negative Effects Element Concentration Negative consequences usually are associated with deficiency or excess of any element. For example, copper deficiency may be associated with increased oxidative stress due to low activity of the cuproenzyme superoxide dismutase. On the other hand, excess free copper ions produce oxidative stress. Ref: Laboratory Evaluations for Integrative and Functional Medicine 2 nd Ed, Lord & Bralley Nutrient & Toxicant Interaction 3 Element deficiency is common and tends to occur in multiples. Poor diet, poor digestion and malabsorption Element-deficient state can cause an up regulation of transport proteins in the GI tract, which can cause greater absorption of toxic elements (element deficiency can increase toxic element exposure) Excessive zinc decreases copper absorption. Copper deficiency increases iron deficiency anemia. Iron deficiency increase the absorption of lead and cadmium. Selenium mitigates the toxic effects of mercury and arsenic. 3

4 Bioavailability of Elements Elements contained in food undergo several changes in chemical bonding. The digestive process must be in good working order. Digestive factors that can decrease element absorption include inadequate (or dilute) stomach acid, low alkaline pancreatic output, or low pancreatic digestive enzymes. Dietary supplements of elements (as elemental salts) are available in many forms. Complexed or chelated forms are usually recommended Lactate, gluconate, citrate, picolinate or amino acid (especially aspartate) salts Salt is an ionic compound, consisting of a cation and anion. In water, the salt dissociates into ions. Choosing the Best Specimen for Element Testing Blood Hair Urine Chelation Challenge (provocation) Testing Urinary Porphyrin Profiling 4

5 There is no singlebest specimen for simultaneous, optimal status assessment of essential elements and toxic heavy metals. For each element, there are merits and limitations of the specimens commonly tested. The best specimen for detecting essential element deficiency depends on the element. Comparing results from multiple types of specimens can provide a more complete picture of elemental status. Blood Whole blood or RBC specimens are valuable when assessing nutrient status. Whole blood is commonly used for baseline, nonchallenged toxic element status. Since each essential element functions synergistically with other elements and nutrients, multi-element profiles coupled with functional biomarkers can provide the best insight into abnormalities in mobilization, utilization and excretion. 5

6 It may be difficult to demonstrate chronic exposure to toxic metals in samples of hair, blood, and urine despite clinically significant body burdens because they tend to accumulate in specific tissues Bone Liver Kidneys Hair Hair specimens can be useful in routine screening for toxic metal exposure. Keratin, which is rich in sulfur, contains cysteine residues, is the major component of hair. When elements, circulating in the blood, reach the hair follicle, they bind with high affinity to keratin. Hair concentrates toxic metals at least 10-fold above concentrations found in blood. Urine Urine elements can vary with recent dietary intake. Over 90% of most chelating agents are cleared by the kidneys in a few hours. Thus, a six to eight hour urine specimen collection is not only more convenient, but also may be superior for assessment of toxic element excretion following a chelation challenge when results are expressed in micrograms per milligram of creatinine. 6

7 Iodine Adequacy Assessment: urinary iodine, TSH, TT 4, TT 3, FT 4, FT 3, RT 3 Optimal forms: Potassium iodide, molecular iodine (iodine I 2 ) (iodide I - ) Clinical indications of deficiency: Goiter, hypothyroidism, hyperthyroidism, fibrocystic breast disease Food sources: Seaweed, shellfish, marine fish, iodized salt Iodine Function, Absorption and Metabolism The normal adult human body contains about mg of iodine, of which 70-80% is concentrated in the thyroid gland. Iodine is an essential element required for normal function of the thyroid gland, immune system, and the integrity of the thyroid and breast tissue. Suboptimal total body iodine status is associated with insufficient intake of the essential element and excessive intake of the highly antagonistic halides: bromide and fluoride. Thyroid Goiter c/237190/goitre 7

8 Specific tissues in the body require adequate iodine and the reduced form of the element iodide for normal metabolism and optimal health. Adequate iodine uptake and organification of iodine by the thyroid gland is required for the production, storage, and release of thyroid hormones. Triiodothyronine (T3) regulates metabolism in several tissues by affecting energy production and neuronal and sexual development. Iodine insufficiency is associated with subclinical thyroid deficiency, weight gain, loss of energy, goiter and impaired mental function. Iodine is also concentrated in breast tissue, where it elicits antiproliferative effects and protection against fibrocystic breast disease and cancer. Iodine and organic iodine compounds are also concentrated and secreted by the gastric mucosa, salivary glands and the cervix. Iodine toxicity Although up to 1000 ug of iodine daily is considered safe, therapeutic does of iodine are not agreed upon, making iodine testing very important. Excessive intake of iodine reduces organic binding of iodine, resulting in hypothyroidism, goiter, thyroiditis, and thyroid nodules. 8

9 Assessing Iodine Status Direct Iodine Measurements Approximately 10 to 20 ug of iodine are lost daily in the feces, and 100 to 150 ug as urinary iodine in iodine-sufficient populations. Guidelines of Appropriate Limits For Spot Urine Iodine Testing Median urinary iodine (ug/l) Iodine intake Iodine nutrition <20 Insufficient Severe iodine deficiency 2-49 Insufficient Moderate iodine deficiency Insufficient Mild iodine deficiency Adequate Optimal More than adequate Risk of iodine-induced hyperthyroidism within 5-10 years following introduction >300 Excessive Risk of adverse health consequences (iodine-induced hyperthyroidism, autoimmune thyroid disease Ref: Laboratory Evaluations for Integrative & Functional Medicine;2 nd ed; Lord & Bralley Twenty-four hour Urine Iodine testing is preferred for its reliability. Normal iodine 24-hour urine collections are ug/d. 9

10 Iodine Plasma/Serum Values only measure circulating thyroid hormones Normal values ug/l Iodine/Iodide status is greatly influenced by dietary intake, but also by exposure to goitrogens that inhibit the absorption and binding of iodine. Goitrogenic substances include chlorine (tap water, pools/hot tubs, cleaning products), fluoride (water toothpaste, mouth wash, some medications) and bromide (pools/hot tubs, baked goods, soft drinks, pesticides, medications). Functional Iodine Tests Iodine patch (skin) test 2% iodine solution (must be color based; not clear iodine solution) is painted on the skin. Observe the time interval for fading of the color. Rapid fading indicates a need for iodine. There are no accepted norms for the time of fading, and the observation is complicated by darker skin tones. Most Functional Medicine practitioners use the 24 hour mark (ex: color should stay on the skin for 24 hrs). Early fading is a sign of deficiency. Urinary Iodine Load Test (Not Recommended By FMU) This test is not recommended by FMU due to the fact that validity of the test depends on the undocumented and erroneous assumption that the average person can absorb at least 90% of a 50 mg dose. 1 10

11 Indirect Iodine Measurements Serum Thyroglobulin TSH T 4 T 3 Iodine Intake Serum Tg Concentration Eufunction (normal thyroid output) Deficiency Adequate Excess Increased Normal Normal or increased hypothyroid Deficiency Adequate Excess Decreased Decreased Decreased hyperthyroid Deficiency Adequate Excess Increased Increased Increased Iodine Deficiency: Thyroid Function Tests Adaptive mechanisms are as follows: Increased serum TSH Increased iodine trapping of the thyroid Preferential synthesis of the thyroid of T3 Increased peripheral conversion to T3 Increased thyroid volume 11

12 Iodine Excess: Thyroid Function Tests Acute iodine excess can cause: Decrease in iodine transport Decreased intrathyroidal organification Decreased release of thyroid hormones from the gland The effect of 15 days of 80 mg oral iodine on thyroid function: Increased serum TSH T4 slightly decreased T3 slightly decreased Effects of Iodine Nutritional Status on Thyroid Function Tests 2 TSH Free T4 Free T3 Other Iodine deficiency Increased Decreased Increased Decreased rt3, increased TG Acute iodine excess Increased Decreased Decreased Acute iodine excess in nodular thyroid gland Decreased Increased Increased Possible development of thyrotoxicosis May appear Chronic iodine excess* normal May appear normal May appear Normal Cordarone Increased Increased Decreased Increased rt3 Clinical Protocols for Lowering Bromide And Fluoride in the Body If your patient is iodine deficient, prescribe iodine/iodide accordingly Stop ingesting bromide & fluoride containing foods and medicines 12

13 The Reactivity Trend of the Halogens (Group 7 of the Periodic Table) Fluoride is more reactive than chloride. Chloride is more reactive than bromide. Bromide is more reactive than iodide. Repletion of Iodine Thyroid function should be monitored during aggressive dosing. Always retest urine. Forms: a mixture of iodine and iodide is recommended Summary 13