Which of the following is not correctly matched?
A. Vitamin B12 – pernicious anaemia
B. Vitamin B6 – loss of appetite
C. Vitamin B1 – beriberi
D. Vitamin B2 – pellagra

Hint: The deficiency of nicotinic acid or niacin causes this disease. If untreated, this disease can kill within four or five years. It is common in people who obtain most of their food energy from corn, notably rural South America, where maize is a staple food.

Complete answer: Pellagra is caused by the deficiency of vitamin B3 also called vitamin niacin. Generally, there are two types of pellagra, primary and secondary. Primary pellagra is caused due to the deficiency of niacin and tryptophan in the diet. While secondary pellagra is caused due to the poor ability to utilise niacin in the diet.
It has the following symptoms:
a) Swelling
b) Hair loss
c) Diarrhoea
d) Weakness
e) Troubled sleep
f) Light sensitivity
g) Dermatitis
h) Aggression
i) Weakened heart
j) Dementia
This condition can be cured by treatment with niacin or nicotinamide supplement. Inclusion of both of the diets is also recommended. Vitamin B3 or niacin is an organic compound that can be obtained from a variety of foods such as meat, poultry, redfish, nuts, legumes and seeds. Other names for Vitamin B3 are niacin, nicotinic acid, vitamin PP and bionic. As a vitamin, it is a precursor of coenzymes NAD and NADP.
Hence, the correct answer is option D.

Note: Niacin deficiency may occur before the signs and symptoms of the pellagra begin to appear on the body of the person. In order to measure the Vitamin concentration in the body, the urinary excretion of the methylated metabolite of N1-methyl-nicotinamide is considered reliable.