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Nutritional Science
Debbie Gurfinkel

NutrientAbsorption and RegulationBioavailabilityFunctionsDeficiencyToxicityFluorinealmost 100 from drinking watertoothpasteCalcium and i replaces hydroxyl in hydroxylapatite to form fluorohydroxyapatite which is less aciddental carriesi Dental fluorosis ii skeletal fluorosisaluminum form soluble than hydroxylapatite ratio of substation of F for OH is 120140insoluble complexes with fluoride tonot essential5080 absorption when consumed with solid foodeffects on growth fertility and anemia reported in mottling from 28mg fluoridedayresults from excessive exposure to fluoride from coal burning industrial exposure tea drinking or ground water that contains fluoride in excess of decrease its ii promotes mineral precipitation from amorphous solutions of calciumphosphate into animal modelsUL levelsabsorptioncrystalline hydroxyl apatite use AIs and 99 absorbed as HF by gastric mucosa passive diffusioncritical exposure is 14 years of age over 8 years of age found in bones implications for human health are unclearis not at riskcrippling effects result from calcification of ligaments muscle wasting and neurological defects and teethhas high affinity for osteoid proteins so it may actually stimulate bone formation and form the center for mineralization blood levels rapidly reflect dietary levels not regulated if discontinue fluoridation increase of 1864 in cannot occur once tooth has erupted into oral cavitymay result from chronic intakes 1020 years of 1020mgday in susceptible individuals genetics plays a role others do not see effects until intake dental carrieslevels above 80mgdayiii topical fluoride decreases acid production by oral plaque Excretion is 90 by kidneys 10 in fecal loss and very minor in sweat10 of 1mgL people experiencewater fluoridation prevents 27 of dental carries in iii Acute toxicityadults6 of 04mgL people experiencenausea vomiting diarrhea acidosis cardiac arrhythmias death occurs with ingestion of 510g5mg64mg fluoridekg bodyweightNutrientAbsorption and BioavailabilityFunctionsDeficiencyToxicityRegulationIodinefound as iodine appears in extracellular i Synthesis of thyroid hormonesT3 amplifies adrenergic response to cold1 in response to low circulating levels of T3 and T4 the hypothalamus ii Cretinism Symptoms of acute toxicityiodide and iodatetissue and can permeate all releases thyrotropinreleasing hormone TRHtissuesThyroxine T4 and Triiodothyronine T3increases cAMP levels by inducing transcription of the beta adrenergic receptor results from thyroid hormone deficiency during gestationburning of mouth throat stomachnonmetaabsorbed in free 2 TRH signals pituitary gland to release thyroid stimulating hormone l form bound to AA 95 of iodine found in TSHmicromior within thyroid thyroid glandnumbers indicate number of iodine on each hormonestimulates lipolysis that helps drive O2 consumption and thermogenesis in BATmental deficiency hearing loss mutism leading preventable cause nausea vomiting diarrhea feverneralhormones of mental retardationthyroxine or 3 TSH signals thyroid gland to produce more T4triiodothyroninethyroid traps iodine999 bound to transport proteins in bloodT3 induces UCP1 that dissipates the mitochondrial proton gradient uncoupling oxidation from ATP synthesis toxic high intakes can also cause thyroid found in aggressivelyand generating heatneuromotor disorders including spasticity and muscular rigiditydysfunction including hyperthyroidism and I form4Rising levels of T4 feedback inhibit synthesis of TRH and TSH in the hypothyroidismKidneys excrete brain8090 of iodide01 free in blood and hormonally activeinteracts with cell receptors use sodium dependant ii Nervous system developmentgrowth failure short statueabout active transport to pump 1520mg iodine against an iodide Iodine is deficient when T4 is not madein bodyfeces is 20gradient that is 4050 times Plasma concentration of T4 is 50x greater than T3 but T3 is 57 times more potentthe plasma concentrationaTyrosine hydroxylase Dry brittle hairfeedback loop is not closedsweat is marginal liver kidney brain pituitary brown adipose tissue can deiodinate T4 to generate T3 loss but can be thyroid gland contains 70through deiodinases Fe dependant enzyme that catalyzes the first step in synthesis of dopamineiii milder hypothyroidismsignificant in hot 80 of total body iodide and humid locations takes up 120micrograms a additional TSH secreted and continues to stimulate thyroid glandwhere iodine daybind to nuclear hormone receptors to modulate gene transcriptiondopamine is a precursor for norepinephrine and epinephrine sensitivity to cold fatigue depression weakness brittle finger nails intakes are unintentional weight gain joint or muscle gaindeficient i results in goiters1 control of basal metabolic ratetyrosine hydroxylase levels and activity are reduced in neuronal cells cultured in hypothyroid mediathyroid hormones regulate oxygen consumption and heat productionb Monoamine oxidaseAbrown adipose tissue BAT is found in human babies small mammals and also in found in neurons and astrogliasmaller extent in adult humans riboflavindependant BAT activates T4 to T3 by using type 2 iodothyronine deiodinase D2catalyze the first step in the breakdown of neurotransmittersincrease T3 concentration of BAT by 4 5 fold within hours
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