Lack of Vitamin A or low levels of this vitamin in human body is known as deficiency of Vitamin A. There are several Vitamin A deficiency symptoms.
Initial Vitamin A deficiency symptoms start with burning, itching and inflammation of eyes followed by several eye conditions.
One major symptom is it causes visual impairment. Major Vitamin A deficiency symptoms include dry eyes, night blindness, reduced vision, eye & Corneal inflammation, rough skin, frequent respiratory infections etc. It might also increase the probability of death in infants.
Primary Vitamin A deficiency
Primary Vitamin A deficiency occurs due to prolonged deprivation of Vitamin A in diet. Primary deficiency causes xerophthalmia, which is a prevalent cause of blindness among young children. Xerophthalmia occurs because of the changes in epithelial tissues of eye. Cornea becomes wrinkled, dry, hazy as well as pigmented. Furthermore, tear glands that are responsible for secretion of tears to keep eyes moist will stop functioning. This further leads to eye inflammation and the last stage is called keratomalacia-softening and then destruction of eyeball, which further leads to complete blindness. Foamy Patches composed of the debris formed due to epithelial tissues are found on temporal side of cornea and are known as Bitot spots.
Secondary Vitamin A deficiency
Secondary Vitamin A deficiency occurs due to several reasons such as interference with storage, transport or absorption of Vitamin A or due to reduction in bioavailability of vitamin A Carotenoids.
What does affect the amount of vitamin A in the body?
Pancreatic diseases, alcoholism and zinc deficiency may affect the amount of vitamin A in body.
Symptoms of Vitamin A Deficiency
Vitamin A deficiency may result from liver disorders, inadequate intake or fat malabsorption. Deficiency of Vitamin A reduces immunity levels in human body. Your body can develop rashes and you may experience typical ocular effects such as night blindness, xerophthalmia (abnormal dryness of cornea and conjunctiva of eyes) etc.
Night blindness, one major symptom of this condition is commonly observed among poor people due to malnutrition.
Males often suffer more from this condition. Night blindness is sometimes because of any physical defect in eye or any other cases.
Vitamin A deficiency that leads to night blindness is known as “functional night blindness”.
Affects maternal mortality in pregnancy
In pregnant women, deficiency of Vitamin A can cause night blindness and it can escalate the risks of maternal mortality.
Vitamin A deficiency impairs immunity, which leads to body’s inability to fight against any infections. This might lead to illnesses and diseases.
Consequences of Vitamin A deficiency in children
Children suffering from Vitamin A deficiency can even die from extreme diarrhea, measles or respiratory infection. Slight deficiency can also affect them in development of bones as well as their overall growth.
Reduced vision in dim light or night
Reduced vision in dim light or night, where the person will not be able to distinguish or recognize outlines of images in reduced illumination. This condition is known as nictalopia.
This condition can be explained as follows:
Protein in retina of the eye is united with vitamin A to form a pigment known as visual purple Rhodopsin. The combination of Retinone (Vitamin-A aldehyde) along with Opsin (protein) forms Rhodopsin. This pigment is bleached in bright light. While during the photochemical process, some levels of vitamin A are lost. Eyes can adapt to the subdued light quickly, if Vitamin A is sufficient. Insufficient levels of vitamin A can reduce vision in dim light or during night. However, this kind of night blindness can turn into some other worse condition wherein the person might lose his vision.
Eye inflammation is yet another symptom of vitamin A deficiency. Burning and itching of eyelids lead to inflammation.
Due to inflammation, the tissues surrounding the eyes and eyelids will get affected. This condition may further lead to corneal inflammation as well. Epithelial changes can severely damage the epithelium of eye in such a way that the condition cannot be cured.
Dry eyes might lead to xerophthalmia, a severe form of night blindness where the outer membrane of eye known as conjunctiva will lose its goblet cells.
These cells will help keep your eyes lubricated and loss of these cells will lead to a severe condition wherein the eye will not produce tears.
These dead goblet cells might accumulate on the outer layer of eye that looks like a form of debris, which will further lead to an infection, or complete loss of vision.
Vulnerability towards respiratory infection
The person might experience vulnerability towards respiratory infection. The lining inside the respiratory organs like throat, nose, bronchi and tracheas become dry and rough. Hence, it would be prone to several bacterial infections.
Hardening (keratinization) and degeneration (atrophy) of epithelium
Vitamin A deficiency leads to hardening (keratinization) and degeneration (atrophy) of epithelium. Hardening of urinogenital tract epithelium is because of vitamin A deficiency, which is followed by bacterial infections. Hence, the patient might also be vulnerable to urinary infections. Few changes can be noticed in reproductive tract as well.
Even skin might show Vitamin A deficiency symptoms. For instance, it might turn rough and dry. Xeroderma (Itching, Scaly and dry skin), follicular hyperkeratosis occur due to deficiency of Vitamin A. Sometimes symptoms may vary. Rashes and peeling of skin is also observed in some cases.
Growth retardation in children
Growth of the child can be halted due to the deficiency of Vitamin A. The younger the person suffering from Vitamin A deficiency, the more severe are its effects. Infections and growth retardation are commonly observed among children.
Increases susceptibility of intestinal infections
Increase in susceptibility of intestinal infections and diarrhea due to severe changes in alimentary tract such as lack of absorption, reduction in secretion of digestive juice etc.
Irregular development of skeleton
Irregular development of skeleton, including vertebral column and skull is also due to deficiency of Vitamin A. This will lead to injury and distortion of spinal cord and brain.
Diagnosis is only based on levels of Vitamin A and typical ocular findings. Treatment consists of either giving vitamin A orally or parentally, if malabsorption is the cause or if symptoms are severe.
Vitamin A is essential for functioning and maintenance of mucous membranes of body. When there is such deficiency, the membranes are porous, thin, dry and flaky. They will not be able to perform their regular functions and this may further lead to bacterial infections.