16. An early sign of retinol deficiencies in man is

A. night blindness
B. keratinization
C. xeropthalmia
D. none of these

17. An enzyme, L-folate reductase reduces folic acid to

A. hydrofolic acid
B. dihydrofolic acid
C. trihydrofolic acid
D. tetrahydrofolic acid

18. What compound of raw egg white causes a syndrome similar to vitamin B deficiency?

A. Avidin
B. Betabindin
C. Ovalbumin
D. Albumin

19. The disease Beriberi is due to a dietary deficiency in

A. vitamin B₁(thiamine)
B.vitamin B₂(riboflavin)
C.vitamin B₆(pyridoxine)
D.vitamin B₁₂

20. Which of these is a symptom of vitamin A deficiency?

A. Osteoporosis
B. Impaired taste perception
C. Blindness
D. Impaired blood clotting