Skin symptoms: dry, peeling and rough skin, followed by papules, which usually occur on the outer side of the upper arm and the extended side of the lower limb, shoulders, buttocks, back and back neck; Due to keratinization of respiratory epithelium, trachea and bronchus are susceptible to infection, and children can also cause bronchopneumonia.

Eye manifestations: It is often manifested as a decline in dark adaptability, that is, when people suddenly enter the darkness from a bright environment, the time for people's eyes to see dark objects is prolonged. In severe cases, people can't see clearly in the dark, and they become night blindness, commonly known as "bird's eye". Severe vitamin A deficiency can also cause dry eye, which is characterized by dry conjunctiva, and children may have conjunctival folds and conjunctival hyperplasia and thickening. Sometimes a triangular, circular or elliptical spot inward of the base is formed on the parallel line between the cornea outside the eyeball and the eyeball, which is grayish white or silvery white and looks like a tiny soap bubble that cannot be wiped off, called "Pitt spot". The luster of conjunctiva and cornea of eyeball decreased, and the secretion of tears decreased or did not secrete tears. More serious can cause corneal ulcer, perforation, and even complete blindness.

Vitamin B 1 deficiency-beriberi;

Vitamin B 1, also known as thiamine, can cause beriberi if it is lacking for a long time.

Susceptible population: those who take polished rice as the staple food for a long time and lack other non-staple food supplements; Infantile beriberi usually occurs in infants of 2 to 5 months.

Clinical manifestations of beriberi:

Dry beriberi: loss of appetite, restlessness, general weakness, heavy lower limbs and numbness at the ends of limbs. Muscle aches and tenderness, especially gastrocnemius of the lower leg, muscle weakness of upper and lower limbs, drooping hands and feet, severe muscle atrophy and numbness, weakening or disappearance of knee joint reflex, often showing symmetry. Babies can also cause hoarseness and aphonia.

Wet beriberi: characterized by edema, more common in the ankle. In severe cases, the whole lower limb is edema. At the same time, palpitation, shortness of breath and enlargement of the right ventricle after exercise often lead to heart failure.

Infantile beriberi (brain type): loss of appetite, vomiting, shortness of breath, pale face, rapid heart rate and even sudden death.

Vitamin B2 and vitamin B2 deficiency;

Clinical manifestations:

Keratitis: wet and white corners of the mouth, chapped corners of the mouth, bleeding, erosion and scabbing.

Glossitis: swelling, cracking, pain, atrophy, thick tongue coating, tongue part falling off to form a map.

Lipitis: dry, cracked, swollen, bleeding and ulcer lips.

Ophthalmitis: blurred vision, fear of light, tears, decreased vision, eye fatigue, corneal congestion.

Skin symptoms: seborrheic dermatitis, mostly occurring on both sides of the nose, cheeks, forehead and eyebrows. Male scrotum itching, redness, desquamation, exudation, scabbing and pain. Female pudendal pruritus, inflammation, and increased leucorrhea.

Secondary anemia: a series of manifestations of iron deficiency anemia may occur.