Vitamin A is required for the formation of rhodopsin, a photoreceptor pigment in the retina. Vitamin A helps maintain epithelial tissue and is essential for the stability of lysosome and glycoprotein synthesis.
Pre-made sources of vitamin A include fish liver oil, liver, egg yolks, butter, and vitamin A-defensive dairy products. Beta-carotene and other provitamin carotenoids, which contain raw vegetables and yellow leaves, carrots, and fruits that are deep or brightly colored, are converted into vitamin A.
Carotenoids are better absorbed from vegetables when cooked or homogenized and are transported with certain fats. Normally, the liver stores 80 A. 90% of vitamin A. body vitamin To use vitamin A, the body releases it into the circulation bound to prealbumin (transthyretin) and retinol-binding proteins.
Retinol activity equivalents (RAE) were developed because provitamin A carotenoids have less vitamin A activity than preformed vitamin A.
Synthetic vitamin analogs (retinoids) are used according to dermatology. The potential role for the protection of beta-carotene, retinol, and retinoids against other epithelial cancers is being investigated. However, the risk of certain cancers may increase after the addition of beta-carotene.
Although malnutrition is rare in developed countries, most people in developing countries do not get enough vitamin A. Those most at risk of pregnancy are pregnant women, breastfeeding mothers, infants, and children. Cystic fibrosis and chronic diarrhea can also increase the risk of deficiency.
Signs and Symptoms
Dry skin
Vitamin A is essential for the formation and repair of skin cells. It also helps fight inflammation due to certain skin problems. Lack of adequate vitamin A can be a factor in the development of eczema and other skin problems.
Eczema is a condition that causes dry, itchy, and hot skin. Several therapeutic studies have shown tretinoin, a prescription drug with vitamin A activity, to be effective in treating eczema.
In one 12-week study, people with chronic eczema who took 10-40 mg of alitretinoin per day experienced a 53% reduction in their symptoms. Keep in mind that dry skin can have many causes, but a chronic vitamin A deficiency can be the cause.
Dry eyes
Eye problems are one of the most common problems associated with vitamin A deficiency. In severe cases, a lack of adequate vitamin A can lead to complete blindness or coral death, characterized by marks called Bitot spots.
Dry eyes, or failure to shed tears, are one of the first signs of vitamin A deficiency. Young children in India, Africa, and Southeast Asia who are malnourished with vitamin A are at greater risk for dry eyes.
Vitamin A supplementation can improve the condition. One study found that high doses of vitamin A reduced the risk of dry eye by 63% in infants and children who took supplements for 16 months.
Blindness at night
Severe vitamin A deficiency can lead to night vision. Numerous observational studies have reported a dramatic increase in night vision in developing countries. Because of the magnitude of the problem, health professionals have worked to improve vitamin A levels in people at risk of night blindness.
In another study, women with night blindness were given vitamin A in the form of dietary supplements or supplements. Both of these forms of vitamin A improve the condition. Women’s ability to adapt to darkness has increased by more than 50% over six weeks of treatment.
Infertility and pregnancy problems
Vitamin A is essential for the production of both men and women, as well as proper growth in infants. If you have a pregnancy problem, vitamin A deficiency can be one of the reasons why. Vitamin A deficiency can lead to malnutrition in both men and women.
Studies show that female rats with vitamin A are more likely to have pregnancy problems and may have embryos with birth defects. Some studies suggest that infertile men may have a greater need for antioxidants due to their high levels of oxidative stress in their bodies. Vitamin A is one of the nutrients that act as an antioxidant in the body.
Vitamin A deficiency is related to pregnancy. A study that analyzed blood levels of various nutrients in women with repeated pregnancies found that they had low levels of vitamin A.
Delayed growth
Children who do not get enough vitamin A can grow up to be depressed. This is because vitamin A is essential for the proper growth of the human body. Numerous studies have shown that vitamin A supplements, alone or with other nutrients, can increase growth. Many of these studies are conducted with children in developing countries.
In fact, a study of more than 1,000 children in Indonesia found that those with vitamin A deficiency who took high-dose supplements at four months grew 0.15 cm (0.39 cm) higher than those who took the placebo. However, a review of studies has found that supplementation with vitamin A in combination with other nutrients can have a greater impact on growth than supplementing with vitamin A alone.
For example, children with unstable growth in South Africa who are exposed to high levels of vitamins and minerals have age-appropriate proportions that were part of the point better than those who received vitamin A.
Throat and chest infections
Frequent infections, especially in the throat or chest, can be a sign of vitamin A deficiency. Vitamin A supplements can help with respiratory diseases, but research results are mixed.
A study of children in Ecuador showed that overweight children who took 10,000 A vitamin A week had fewer respiratory infections than those who received a placebo. On the other hand, a review of research in children found that vitamin A supplements could increase the risk of throat and chest infections by 8%.
The authors have suggested that supplements should be given only to those with a real problem. Also, according to some studies in the elderly, high blood levels of provitamin A carotenoid beta-carotene can protect against respiratory infections.
Healing of a bad wound
Wounds that do not heal properly after injury or surgery may be linked to low levels of vitamin A. This is because vitamin A promotes the production of collagen, an essential component of healthy skin. Studies suggest that both oral and topical vitamin A can strengthen the skin.
Studies in mice found that oral vitamin A improved collagen production. The vitamin had this effect even though mice were taking steroids, which could prevent wound healing.
Further studies in mice have found that treating the skin with topical vitamin A has been shown to protect the wounds associated with diabetes. Research in humans shows similar results. Older men who treated the wounds with topical vitamin A had a 50% reduction in their wound size, compared to men who did not use cream.
Acne and outbreaks
As vitamin A promotes skin growth and fights inflammation, it can help prevent or treat acne. Many studies have linked low levels of vitamin A with the presence of acne. In one study of 200 adults, vitamin A levels in those with acne were more than 80 mcg lower than in those without the condition.
Topical and oral vitamin A can cure acne. Studies show that creams containing vitamin A can reduce acne by up to 50 percent. The most well-known oral vitamin A is used to treat acne isotretinoin or Accutane. This drug can be very effective in treating acne but can have many side effects, including mood swings and birth defects.
Dangers of Too Much Vitamin A
Vitamin A is essential for life. Still, much of it can be dangerous. Hypervitaminosis A, or vitamin A toxicity, is usually taken by taking high-dose supplements for a long time. People do not usually get much vitamin A from food alone.
Excess vitamin A is stored in the liver and can lead to poisoning and problematic symptoms, such as blurred vision, inflammation of the bones, dry and scarred skin, mouth sores, and confusion.
Pregnant women should be especially careful not to consume too much vitamin A to prevent possible birth defects. Always check with your health care provider before starting vitamin A supplements.
People with certain health conditions may need a high amount of vitamin A. However, most healthy adults need 700-900 mcg per day. Women nurses need more, while children need less.
Diagnosis
Serum retinol levels, clinical trials, and response to vitamin A
Ocular findings suggest a deficiency of vitamin A. Adaptation to dark conditions can be impaired in other diseases (e.g., zinc deficiency, retinitis pigmentosa, severe retinal detachment, cataract, diabetic retinopathy). If the black mutation does not work properly, rod cytometry and electroretinography are performed to determine if vitamin A deficiency is the cause.
Serum retinol levels are measured. The typical range is 28 to 86 mcg/dL (1 to 3 mmol/L). However, levels decrease only after an advanced deficiency because the liver contains large stores of vitamin A. Also, reduced levels may result from a severe infection, causing the protein binding of retinol and transthyretin (also called prealbumin) to decrease slightly. A vitamin A therapy trial can help confirm the diagnosis.
Prevention
The diet should include raw vegetables with green leaves, deep or brightly colored fruits (eg papaya, oranges), carrots, and yellow vegetables (eg squash, pumpkin). Milk and whole grains are rich in vitamin A, liver, egg yolks, and fish liver oil. Carotenoids are better absorbed when used with certain dietary fats. If suspected allergies to milk are suspected in children, they should be given enough vitamin A for their milk supply.
In developing countries, prophylactic supplements of vitamin A palmitate in 200,000 units of oil (60,000 doses of retinol equivalent) orally every six months are recommended for all children between the ages of 1 and 5 years; infants – 6 months may be given a simultaneous dose of 50,000 units (15,000 RAE), while those aged 6 to 12 may be given a single dose of 100,000 units (30,000 RAE).
Treatment
Vitamin A palmitate
Vitamin A deficiency is traditionally treated with vitamin A palmitate in 60,000 units of oil once a day for two days, followed by 4500 units orally once a day. If vomiting or malabsorption is present or xerophthalmia is possible, an average of 50,000 units for infants – six months, 100,000 units for children 6 to 12 months, or 200,000 units for children – 12 months and adults should be given two days, with a third dose at least 2 weeks later. Similar dosages are recommended for children and children with complex measles.
Vitamin A deficiency is a risk factor for severe measles; Vitamin A treatment can reduce the duration of the disease and can reduce the severity of symptoms and the risk of death. It is recommended that all children with measles receive 2 doses of vitamin A (100,000 units for children – 12 months and 200,000 units in those 12 months) given 24 separate hours.
Infants born to HIV-positive mothers should receive 50,000 units (15,000 RAE) within 48 hours of birth. Long-term administration of large doses, especially in children, should be avoided as they may be toxic.
For pregnant or breastfeeding women, the prophylactic or therapeutic dose should not exceed 10,000 units (3000 RAE)/day to avoid possible harm to the fetus or baby.
FAQ
What causes lack of vitamin A?
Vitamin A deficiency can result from inadequate intake, fat malabsorption, or liver disorders. Deficiency impairs immunity and hematopoiesis and causes rashes and typical ocular effects (eg, xerophthalmia, night blindness).
How do you fix vitamin A deficiency?
Treatment for subclinical VAD includes the consumption of vitamin A-rich foods, such as liver, beef, chicken, eggs, fortified milk, carrots, mangoes, sweet potatoes, and leafy green vegetables. For VAD syndromes, treatment includes daily oral supplements, as follows: Children aged 3 years or younger - 600 mcg (2000 IU)
How common is vitamin A deficiency?
More than 75% of people who eat a Western diet get more than enough vitamin A and do not need to worry about deficiency. However, vitamin A deficiency is very common in many developing countries. About 44–50% of preschool-aged children in certain regions have vitamin A deficiency.
How long does it take to go blind from vitamin A deficiency?
About 250,000 to 500,000 malnourished children in the developing world go blind each year from a deficiency of vitamin A, around half of whom die within a year of becoming blind.
