Chapter 11 – Fat-Soluble Vitamins A, D, E, K

A set of question-and-answer flashcards reviewing names, functions, deficiencies, food sources, recommendations, and upper limits for vitamins A, D, E, and K as presented in Chapter 11.

What are the main physiological roles of vitamin A?

Vision; maintenance of cornea, epithelial cells, mucous membranes, and skin; bone and tooth growth; reproduction; and immunity.

Which compound is a plant precursor of vitamin A and is abundant in dark-green leafy and deep-orange produce?

Beta-carotene.

What eye disorder, progressing from night blindness to corneal degeneration and blindness, results from severe vitamin A deficiency?

Xerophthalmia (includes night blindness, xerosis, keratomalacia, and corneal degeneration).

Which vitamin A–related deficiency symptom involves plugging of hair follicles with keratin?

Hyperkeratosis.

Name three rich food sources of pre-formed vitamin A (retinol).

Fortified milk, fish, and liver.

List four vegetables or fruits that are high in beta-carotene.

Carrots, sweet potatoes, spinach (or other dark-green leafy vegetables), and apricots (any deep-orange fruit or vegetable qualifies).

Which vitamin, also called calciferol, raises blood calcium by enhancing intestinal absorption, mobilizing bone calcium, and reducing renal losses?

Vitamin D.

What childhood disease characterised by soft, weak bones is caused by vitamin D deficiency?

Rickets.

Name the two bone disorders in adults that can result from vitamin D deficiency.

Osteomalacia and osteoporosis.

Besides fortified milk, give two natural sources of vitamin D.

Sunlight exposure and fatty fish (such as salmon, herring, or sardines) or their oils; liver is another source.

Which fat-soluble vitamin (alpha-tocopherol) acts as a major antioxidant protecting polyunsaturated fatty acids in cell membranes?

Vitamin E.

What is the classic sign of vitamin E deficiency in premature infants?

Red blood cell breakage (erythrocyte hemolysis).

Which nervous system effect can appear with prolonged vitamin E deficiency?

Nerve damage.

What common food ingredient is the richest dietary source of vitamin E?

Vegetable oils (and foods made with them).

Which vitamin, synthesized by intestinal bacteria, is essential for activating several blood-clotting proteins?

Vitamin K.

What is the primary clinical manifestation of vitamin K deficiency?

Hemorrhage due to impaired blood clotting.

List two dietary sources of vitamin K.

Dark-green leafy vegetables and vegetable oils (in addition to synthesis by gut bacteria).