21.Studies in developing countries have demonstrated that the mortality rate of children with measles can be significantly reduced by providing which of the following supplements?

a.iron

b.vitamin A

c.folic acid

d.phylloquinone

22.What is the name of the colour pigment which has no vitamin A activity and is red and                                           yellow in colour?

a.xanthophyll

b.chlorophyll

c.anthocyanin

d.betalains

23.What is the first detectable sign of vitamin A deficiency?

a.xerosis

b.xerophthalmia

c.night blindness

d.corneal keratinization

24.Which of the following is associated with the condition known as xerosis?

a.toxicity of vitamin K

b.toxicity of beta-carotene

c.deficiency of vitamin A

d.deficiency of vitamin D

25.Which of the following is a carotenoid which has shown positive effects with reducing risk for prostate cancer?

a.beta-carotene

b.alpha-carotene

c.zeaxanthin

d.lycopene

26.In which of the following population groups are the effects of vitamin A deficiency most severe?

a.adults

b.elderly

c.preschool children

d.adolescents

27.Which of the following is most likely to occur from a prolonged dietary deficiency of vitamin A?

a.osteomalacia

b.osteoporosis

c.xerophthalmia

d.prolonged blood-clotting time

28.What causes keratinization?

a.toxicity of vitamin A

b.toxicity of vitamin D

c.deficiency of vitamin A

d.deficiency of vitamin D

29.What part of the body is affected most by keratomalacia?

a.bone

b.liver

c.cornea

d.immune cells

30.Which of the following conditions may keratinization of lung cells?

a.toxicity of vitamin A

b.toxicity of beta-carotene

c.deficiency of vitamin A

d.deficiency of vitamin D