Which diseases are caused due to deficiency of nutritive substances/nutrients? What are their symptoms?

(A) In many developing countries of South and South-East Asia,West and Middle Africa,the deficiency of protein and total food is widespread.
$PEM$ (Protein-Energy Malnutrition) affects the population during droughts and political instability.
$Marasmus$ and $Kwashiorkor$ are commonly seen in children.
$(i)$ $Marasmus$: It occurs due to a simultaneous deficiency of proteins and calories. It is seen in children below $1$ year of age. It occurs due to the replacement of mother's milk by other insufficient nutritious foods very early.
Symptoms: Protein deficiency,stunted growth,breakdown of tissue proteins,very weak body,thinning of limbs,and dry,thin,wrinkled skin. $A$ noticeable decrease is seen in growth rate and body weight. Brain growth and development are impaired.
$(ii)$ $Kwashiorkor$: It occurs due to protein deficiency. It is seen in children above $1$ year of age,caused by a diet high in calories but low in protein replacing mother's milk. Symptoms include: muscle wasting,thinning of limbs,impaired brain growth and development,but some fat remains deposited under the skin,and swelling (edema) occurs in some parts of the body.