Medical writer: Samantha Agcaoil
Vitamin A is essential for many physiological processes, and a lack of it could lead to various problems. Specifically, it is crucial for our sight. The range of eye problems resulting from the shortage of the first vitamin ever discovered is referred to as vitamin A deficiency eyes.
What Is Vitamin A?
Vitamin A is not one substance but a name for a group of fat-soluble retinoids. The human body cannot produce this vitamin, so we need to receive it with food. Suppose you are having an omelet and a glass of orange juice for lunch. Eggs and other livestock products are rich in vitamin A. Orange juice, as well as bright red and dark green plants, contain provitamin A. Since the human body turns provitamins into vitamins, you can still get the needed amount of vitamin A even if you prefer a green salad to an omelet.
Our body absorbs vitamin A in the presence of fat. While meat, fish, or eggs already contain some fat, adding a bit of oil to your vegetarian spinach is recommended to metabolize more vitamin A.
Vitamin A and Vision
Vitamin A is vital for the health of the retina and its ability to respond to light. It is also responsible for keeping an eye moisturized. So, if you wonder deficiency of which vitamin causes loss of vision, vitamin A is on the list.
What Is Vitamin A Deficiency?
Human body stores vitamin A in the liver. When it does not receive enough vitamin A over some time, the lack starts to affect the immune system, sight, and cell growth, which all depend on vitamin A.
Some problems are reversible and could be mended with an additional intake of the missing vitamin. As soon as a patient receives the needed amount, the retina goes back to its normal function and responds to all spectrum of light.
Nevertheless, if the mucous membrane lacks moisturizing, the corneal tissue degenerates, which can cause blindness.
Who Is at Risk for Vitamin A Deficiency?
Some people do not get enough vitamin A with food because of poverty and a scarce diet. A person with cystic fibrosis might get a sufficient amount of the vitamin but have difficulties with absorbing it. Insufficient protein and iron consumption often produce the same effect. People suffering from fibrosis, liver disorders, fat malabsorption, pancreatic insufficiency, and lower gastrointestinal tract inflammations are also at risk. Besides, those who abuse alcohol may face the deficiency coupled with liver toxicities caused by the vitamin.
What Are the Symptoms of Vitamin A Deficiency?
Sight problems often develop when the body lacks vitamin A. Night blindness, which inflicts difficulty in seeing in the darkness, is the most typical among vitamin A deficiency eye symptoms. It often leads to xerophthalmia, pathologic eye dryness. Susceptibility to infection is another common symptom associated with the deficiency.
How Is Vitamin A Deficiency Diagnosed?
Worrying sight-related symptoms often help to diagnose the problem. Lifestyle and background are taken into account too. It is possible to do a blood test to check the level of vitamin A, but the difficulty is that the test does not show how much vitamin the liver holds. The liver works as a vitamin A bank for the body and releases it to the blood when needed. An amount of cash in your wallet does not show the amount in your bank account. You do not lack cash until the account is emptied. The same goes for vitamin A – until the reserve is used up, there will be a sufficient level of vitamin A in the blood.
How Is Vitamin A Deficiency Treated?
Such food as the animal liver is extremely high in vitamin A. Oily fish, eggs, and dairy products are also good sources of it, while carrot, squash, and broccoli fall under the best vegetarian vitamin A-rich foods for eyes.
A vitamin A supplement or multivitamin complex improves the situation with the deficiency too.
But if the reason for the deficit lies in a metabolism problem, it requires separate treatment.
Prevention
A healthy diet rich in vitamin A and quality supplements can help avoid the problem. An adult receiving wholesome nutrition is unlikely to experience the deficiency unless they have a severe medical problem. A preterm child is at risk of vitamin A deficiency since their liver could not accumulate its necessary amount. In such cases, medication treatment is arranged to prevent possible slow development.
Vitamin A Overdose
You can receive too much vitamin A from animal food or an excessive amount of supplements. A single administration of an extreme dose can cause nausea, headache, and more severe symptoms.
It is not possible to overdose on provitamin A that comes from plants. Too much carrot juice might color a person’s skin orange-yellow, but the usual shade returns once the consumption drops.
