Which diseases is caused due to lack vitamin A?

Vitamin A;

The first recognized fat-soluble vitamin is vitamin A that is found in the body in its three active forms ; retinal, retinol and retinoic acid that are collectively known as retinoid.

They are essential for normal vision, support preproduction and growth , participate in protein synthesis and maintain healthy epithelial tissue. The RDA of vitamin A is 900 micro g per/day foe male adult and 700micro g per/day for female adult.

Vitamin Deficiency;

They inadequate intake of vitamin A may lead to vitamin A deficiency diseases, which affect more than 100 million children worldwide . Following are the detectable signs and symptoms vitamin A deficiency:

Night blindness:

The first detectable signs of vitamin A deficiency is nyctalopia, which is characterized by ''the inability to see well at night or in poor light''. The main cause for night blindness is the insufficient intake of vitamin A . The retina, the back of the eye does not receive enough retinal to regenerate the visual pigment bleached by light.

Blindness:

Apart for blindness, the complete blindness failure to see at all ' is also attributed at cornea(front of the eye) due to the deficient intake of vitamin A . Xerophthalmia (dry eye) is the blindness caused by severe vitamin A deficiency and is a consequence of keratinization of the conjunctival nd corneal surfaces of the eyes which may be followed by infection stages.

a) The conjunctiva become dry resulting in a condition known as conjunctival xerosis.

b) The cornea become dry and hard, leading to a condition known as corneal xerosis.

c) Corneal xerosis progresses toward softening of cornea, a condition known as keratomalacia

Keratinization: A signs of vitamin A deficiency in which the skin becomes dry, rough and scaly due to accumulation of keratin.

Bitot' s spots: Bitot ' s spots are one of the signs of vitamin A deficiency that are associated with drying of cornea. Precisely, they are attributed to the build- up of keratin located in the conjunctiva of human 's eyes. They can adapt oval ,triangular or irregular shape.

Apart from affecting vision, vitamin A deficiency may lead to anemia, diarrhea, changes in lining, cessation of bone growth, impaired teeth enamel formation(cracks in teeth and tendency to decay) and suppression of immune responses.

Vitamin A toxicity:

Just as vitamin A deficiency disturb body functions, so does its toxicity, which is often associated with the supplement abuse. When the available binding proteins are engulfed, the toxicity symptoms arise, resultantly; free vitamin A damages the cells. Overconsumption of vitamin A lead to following symptoms;

Hypervitaminosis :

''A condition by the accumulation of too much of vitamin A precursor (beta- carotene) in the blood which turn the skin noticeably yellow.

Digestive symptoms:

Nausea, vomiting, abdominal pain and diarrhea.

Neurological:

Loss of appetite, irritability, fatigue, insomnia and headache.

Skin symptoms:

Dryness, peeling, itching, rashes and scaling.

Decalcification: Caused by the high level of vitamin A in blood increasing the activity of osteoclasts (cells that destroy the bone during its growth)

Birth defects: The intake of vitamin A in excessive amount can lead to teratogenic risk9abdominal fetal development).

Amenorrhea: The absence the menstruation is one of the symptoms manifested due to elevated serum carotene concentration.

Jaundice: The condition is characterized by ''spilling of bile and related pigment in to the bloodstream leading to yellowness of skin.

Enlargement of liver: Due to accumulation of fasts and vitamin A in liver.

Source of vitamin A;

Vitamin A is found in two main forms: preformed vitamin A, also known as retinol, which comes from animal sources, and provitamin A, most commonly as beta-carotene, which comes from plant sources. Here are some rich sources:

Animal Sources (Preformed Vitamin A):

Liver and fish oils: These are among the richest sources of vitamin A.

Dairy products: Milk, butter, cheese, and yogurt are good sources of vitamin A.

Eggs: The yolks contain vitamin A.

Plant Sources (Provitamin A):

Leafy green vegetables: Foods like spinach, kale, and collard greens are high in beta-carotene.

Orange and yellow vegetables and fruits: Carrots, sweet potatoes, pumpkins, mangoes, and apricots are good sources.

Tomatoes: They're rich in beta-carotene.

Cantaloupe and other melons.

Benefits of Vitamin A:

Eye Health: Vitamin A is critical for maintaining vision. It is a component of the protein rhodopsin, which the retina of the eye needs to absorb light.

Immune Support: Vitamin A is necessary for the health and functioning of the immune system. It plays a critical role in the growth and distribution of T cells, a type of white blood cell that protects the body from infection.

Skin Health: It aids in the growth and distribution of skin cells. A deficiency in vitamin A can lead to a dry, scaly complexion.

Bone Health: While Vitamin D is most commonly associated with bone health, Vitamin A is also crucial for proper bone growth and development. A deficiency in Vitamin A can lead to poor bone health.

Reproductive Health: Both males and females require vitamin A for the normal growth and development of embryos during pregnancy and the proper function of the reproductive system.