The nutrients specifically required for thyroid hormone production are tyrosine, iodine, and selenium, in addition to zinc and several B vitamins. While magnesium, manganese, and methionine are all essential for metabolism and overall hormone production, they are not direct substrates or cofactors in the production of thyroid hormone.

Selenium is essential for conversion of T4 to T3. Deiodinase enzymes, which remove iodine from T4 during conversion into T3, are selenium dependent. Tyrosine and iodine are both required for synthesis of T4, and iron is the cofactor for conversion of phenylalanine into tyrosine.

Tyrosine and iodine are both precursors for synthesis of T4. Selenium is essential for conversion of T4 to T3, and iron is the cofactor for conversion of phenylalanine into tyrosine.

Calcitonin is produced by the parafollicular (c cells) of the thyroid as a response to elevated blood calcium levels. Calcitonin reduces plasma calcium by inhibiting osteoclast activity and stimulating osteoblasts to deposit more bone. Parathyroid hormone has the opposite effect - it acts to increase calcium levels when serum calcium decreases. While they may ultimately affect serum calcium levels, thyroid hormone and cortisol are not directly involved in calcium homeostasis.

Thyroid-stimulating hormone (TSH) is produced in the anterior pituitary. Somatostatin, dopamine, and gonadotropin releasing hormone are all hypothalamic hormones. Somatostatin is also secreted by the pancreas, and slows down digestive processes. To remember the hormones of the anterior pituitary, use the following mnemonic: FLAT PEG, Follicle-stimulating hormone, Luteinizing hormone, Adrenocorticotropic hormone, Thyroid-stimulating hormone, Prolactin, Endorphins, Growth hormone.

Epinephrine is the only hormone of those listed that is produced by the adrenal medulla. The adrenal medulla is the center of the adrenal gland. Antidiuretic hormone is produced by the posterior pituitary. Calcitonin is produced by the thyroid. Thyroid-stimulating hormone is secreted from the anterior pituitary, as is follicle-stimulating hormone. 

Oxytocin is produced by the hypothalamus, and is released by the posterior pituitary. Women experience an increased level of oxytocin during labor, after birth, and while breastfeeding. It helps to increase uterine contractility, aiding in the delivery process and preventing hemorrhage after birth. Progesterone and estrogen are hormones released from the ovary. Estrogen is has many effects on the body, one of which is the development of sex characteristics in females. Progesterone is important in regulation of the uterine lining. Prolactin is made by the anterior pituitary gland and functions in the production on breast milk. 

All of these are correct effects of parathyroid hormone. The kidneys resorb calcium and as a result, less is released into the urine. The intestines absorb additional calcium from food and calcium is released from the bone through the work of osteoclasts. 

Thyroid-stimulating hormone (TSH) is produced by the anterior pituitary. TSH causes the thyroid to release thyroid hormones (T3 and T4). A TSH blood test is often ordered to diagnose hypoactive thyroid. 

Aldosterone is a hormone secreted by the adrenal glands. Serum aldosterone levels vary throughout the day. Aldosterone presence is highest in the morning. Of the answer choices, 7 AM is the best choice. A physician may have the patient come to the office at a specific time of day for this reason.