Deck 32: Medical Nutrition Therapy for Thyroid and Related Disorders

Question 1

Characteristics of chronic adrenal stress do NOT include:

A)increased thyroid-binding protein activity.
B)decreased conversion of T4 to active forms of T3.
C)weakened immune barriers of the digestive tract, lungs, and brain.
D)increased sensitivity to thyroid hormones.

Answer 1

D
Chronic adrenal stress results in decreased sensitivity to thyroid hormones.

Question 2

Iodine deficiency is often a culprit in thyroid disorders.However, in which of these thyroid conditions may supplementing with iodine exacerbate the condition?

A)Adrenal fatigue
B)Hashimoto's thyroiditis
C)Polycystic ovary syndrome (PCOS)
D)Graves' disease

Answer 2

B
In autoimmune Hashimoto's thyroiditis, supplementing with iodine may exacerbate the condition.Because iodine stimulates production of TPO, this in turn increases the levels of TPO antibodies (TPO Abs) dramatically, indicating an autoimmune flare-up.Some people develop symptoms of an overactive thyroid, but others have no symptoms despite tests showing an elevated level of TPO Abs.Therefore, one must be cautious regarding the use of iodine.Furthermore, although iodine deficiency is the most common cause of hypothyroidism for most of the world's population, in the United States and other westernized countries, Hashimoto's thyroiditis accounts for the majority of cases.

Question 3

Selenium deficiency, inadequate protein, excess carbohydrates, chronic illness, and stress (high cortisol levels) can all impact what thyroid metabolic process?

A)Thyroid-stimulating hormone (TSH) production
B)Organification of iodide
C)Thyroid-binding globulin (TBG) T4 transport
D)5'-deiodinase conversion of T4 to T3

Answer 3

D
Changes in 5'-deiodination occur in a number of situations, such as stress, poor nutrition, illness, selenium deficiency, and drug therapy.Toxic metals such as cadmium, mercury, and lead have been associated with impaired hepatic 5'-deiodination in animal models.Free radicals are also involved in inhibition of 5'-deiodinase activity.

Question 4

Polycystic ovary syndrome (PCOS) is characterized by which of the following biochemical and endocrine abnormalities?

A)Elevated testosterone, insulin resistance, and impaired glucose tolerance
B)Thyrotoxicosis, iodine deficiency, and elevated estrogen
C)Impaired glucose tolerance, increased T4 conversion, and hypertension
D)Low blood calcium, thyroid receptor hypersensitivity, and elevated cortisol

Question 5

Before 1960, reports surfaced that soy formula-fed infants were developing hypothyroidism.The addition of what supplement to these formulas ameliorated this problem?

A)Iodine
B)Selenium
C)Iron
D)Tyrosine

Question 6

A severe systemic illness that causes decreased peripheral conversion of T4 to T3, an increased conversion of T3 to the inactive rT3, and decreased binding of thyroid hormones is known as:

A)Hashimoto's thyroiditis.
B)Graves' disease.
C)euthyroid sick syndrome.
D)Addison's disease.

Question 7

Botanical preparations have been found in animal studies to influence thyroid activity.Commiphora mukul (guggulsterones from guggul extract) has strong thyroid stimulatory action, demonstrated by:

A)increasing cortisol production.
B)decreasing iodine uptake by the thyroid.
C)increasing TPO activity.
D)decreasing serum T4 concentrations.

Question 8

Low energy, cold hands and feet, fatigue, hypercholesterolemia, muscle pain, depression, and a positive test result for thyroid peroxidase antibodies could all be indicative of what condition?

A)Diabetes mellitus
B)Graves' disease
C)Hashimoto's thyroiditis
D)Polycystic ovary syndrome (PCOS)

Question 9

Maintaining thyroid hormone function throughout the aging process appears to be an important hallmark of healthy aging.What characteristic is an indicator of thyroid health in centenarians?

A)Decreased free T4 and rT3 levels
B)An increased libido
C)Constant cortisol production
D)The absence of circulating thyroid autoantibodies

Question 10

Although some T3 is produced in the thyroid, approximately 80% to 85% is generated outside the thyroid in which organs?

A)Nervous system and adrenal glands
B)Liver and kidneys
C)Pancreas and gastrointestinal tract
D)Hypothalamus and pituitary gland

Question 11

Which of these is NOT a product of the thyroid?

A)Thyroxine (T4)
B)Calcitonin
C)Reverse T3 (rT3)
D)Triiodothyronine (T3)

Question 12

A rare primary adrenal insufficiency in which insufficient levels of steroid hormones are produced despite adequate levels of the hormone ACTH is known as:

A)adrenal fatigue.
B)Addison's disease.
C)Cushing's syndrome.
D)euthyroid sick syndrome.

Question 13

Thyroid health has been shown to be impacted by the elimination of which foods?

A)Seafood
B)Gluten
C)Mushrooms
D)Barley

Question 14

Some plant foods (cauliflower, broccoli, cabbage) exert antithyroid activity through what mechanism?

A)Binding iodine species
B)Inhibiting thyroid peroxidase
C)Increasing thyroglobulin antibodies
D)Simulating cortisol

Question 15

Thyroid heath in some adults can be improved by increasing the conversion of T4 to T3.This can be accomplished by:

A)supplementing with tyrosine.
B)correcting zinc deficiencies with zinc glycinate or zinc citrate.
C)increasing naturally occurring flavonoids in the diet.
D)cautiously supplementing with lipoic acid.

Question 16

More than 90% of people with autoimmune thyroid disease have a genetic defect affecting their ability to metabolize what?

A)Vitamin D
B)Flavonoids
C)Selenium
D)Tyrosine

Question 17

Graves' disease is an autoimmune disease in which the thyroid is diffusely enlarged (goiter) and overactive, producing an excessive amount of thyroid hormones.It is the most common cause of hyperthyroidism (overactive thyroid) in the United States.What is the primary target of circulating autoantibodies in this disease?

A)Insulin receptors
B)Thyroid-stimulating hormone (TSH) receptors
C)Thyrotropin-releasing hormone (TRH) receptors
D)Cortisol receptors

Question 18

Cushing's syndrome is characterized by weight gain, easy bruising, depression, muscle loss, and weakness.It is caused by:

A)an increased concentration of endocrine autoantibodies.
B)thiocyanate ions, which can compete with iodine for uptake by the thyroid gland.
C)too much cortisol remaining in the bloodstream over a long period.
D)thyroid hormone deficiency during pregnancy.

Question 19

Dietary intervention is a key therapeutic tool in managing patients with thyroid disease.In the absence of nutritional deficiencies, what is the main goal of nutritional support?

A)Maintaining vitamin sufficiency
B)Decreasing oxidative stress
C)Increasing iodine concentrations
D)Reducing antithyroidal antibodies

Question 20

Which of these is NOT required for the production of thyroxine (T4) and triiodothyronine (T3)?

A)Thyroid peroxidase (TPO)
B)Tyrosine
C)Thyroid-binding globulin (TBG)
D)Iodide