Clinical Nutritionist CCN Micronutrients and Deficiencies 2

Question 1

Which B vitamin acts as a coenzyme in over 100 enzymatic reactions, particularly amino acid metabolism?

Accepted Answer

Pyridoxine (vitamin B6)

Answer

Vitamin B6 as pyridoxal phosphate (PLP) is a cofactor for aminotransferases, decarboxylases, and other enzymes central to amino acid metabolism.

Question 2

Zinc deficiency is characteristically associated with which clinical finding?

Accepted Answer

Impaired taste and smell (hypogeusia/anosmia)

Answer

Zinc deficiency causes hypogeusia (reduced taste acuity), anosmia, poor wound healing, growth retardation, and immune dysfunction.

Question 3

What is the Tolerable Upper Intake Level (UL) for preformed vitamin A (retinol) in adults?

Accepted Answer

3,000 mcg RAE/day

Answer

The UL for preformed vitamin A is 3,000 mcg RAE/day for adults; excess intake causes hypervitaminosis A with symptoms including liver toxicity and teratogenicity.

Question 4

Selenium functions primarily as a component of which enzyme system that protects against oxidative stress?

Accepted Answer

Glutathione peroxidase

Answer

Selenium is an essential component of glutathione peroxidases (GPx), selenoenzymes that reduce hydrogen peroxide and lipid hydroperoxides to protect cells from oxidative damage.

Question 5

Which fat-soluble vitamin acts as an antioxidant by protecting polyunsaturated fatty acids in cell membranes from oxidation?

Accepted Answer

Vitamin E (alpha-tocopherol)

Answer

Alpha-tocopherol, the most biologically active form of vitamin E, donates a hydrogen atom to lipid peroxyl radicals, interrupting the chain reaction of lipid peroxidation.

Clinical Nutritionist CCN Practice Test

Clinical Nutritionist CCN Practice Test

Clinical Nutritionist CCN Micronutrients and Deficiencies 2