Phospholipids are the main constituents of body fat in humans and other animals.

A、The compound is necessary for health, but the body is unable to synthesize enough of the compound to maintain health

B、The compound prevents chronic disease and cancer.

C、The compound is best absorbed if taken in supplement form.

D、The body is unable to synthesize the compound.

A、All vitamins consumed in excess are excreted.

B、Supplemental vitamins are better than those from food.

C、Occasional lapses in vitamin intake should cause no harm.

D、It is hard to get all the vitamins we need from food.

A、Water-soluble vitamins are best absorbed in the presence of dietary fat.

B、Fat-soluble vitamins have much less potential for toxicity.

C、Water-soluble are less likely to be toxic.

D、Water-soluble vitamins are stored, whereas fat-soluble vitamins are excreted readily.

A、They are water soluble.

B、They serve as coenzymes.

C、They can be lost during food processing and preparation.

D、They are stored in adipose tissue.

A、In general, excesses of fat-soluble vitamins cannot be excreted as easily as water-soluble vitamins.

B、In general, water-soluble vitamins are more likely to be stored in the body than fat-soluble vitamins.

C、The body has higher requirements for water-soluble vitamins.

D、The body has higher requirements for fat-soluble vitamins.

A、Retinol is found only in plant foods.

B、Certain carotenoids are precursors for preformed vitamin A.

C、Vitamin A is necessary for normal blood clotting.

D、In children, vitamin A deficiency is called rickets.

A、beta-carotene.

B、collagen.

C、free radicals.

D、vitamin D

A、Fatty fish and fish oils

B、Dark orange and yellow vegetables

C、Whole-grain breads and cereals

D、Red meat

A、metabolizes vitamin E.

B、transmits nervous impulses.

C、helps form DNA.

D、protects fatty acids from oxidation.