Which vitamin is known as the anti-infection vitamin?

Which group of three of the following five statements $(1-5)$ contains all three correct statements regarding beri-beri?
$1.$ $A$ crippling disease prevalent among the native population of sub-Saharan Africa.
$2.$ $A$ deficiency disease caused by lack of thiamine (vitamin $B_1$).
$3.$ $A$ nutritional disorder in infants and young children when the diet is persistently deficient in essential protein.
$4.$ Occurs in those countries where the staple diet is polished rice.
$5.$ The symptoms are pain from neuritis,paralysis,muscle wasting,progressive oedema,mental deterioration,and finally heart failure.

Rickets in children and osteomalacia in adults is caused by the deficiency of

Which of the following pairs shows symptoms like swollen lips,thick pigmented skin on the hands,and irritability?

When breast feeding is replaced by less nutritive food low in proteins and calories,infants below the age of one year are likely to suffer from: