Vitamin A is a fat-soluble vitamin essential for many functions of the body, including a good immune system and proper vision.
However, pregnant women, breastfeeding mothers, and children are at risk of vitamin A deficiency.
You can get vitamin A from meat, dairy products, eggs, and plant foods. Preformed vitamin A and provitamin A are the two kinds of vitamin A found in foods.
Preformed vitamin A, also known as retinol, is the active form found in a variety of foods, including meat, fish, eggs, and dairy products (1).
On the other hand, provitamin A is found in fruits and vegetables in its inactive form, such as the carotenoids alpha-carotene, beta-carotene, and beta-cryptoxanthin.
The inactive form ”provitamin A” is converted into an active form in your body. In your small intestine, for example, beta-carotene is converted to retinol, and retinol is an active form of vitamin A (2).
This article reviews vitamin A deficiency signs and symptoms.
Night Blindness
A deficiency of vitamin A may cause night blindness (3).
Several observational studies show that night blindness is the sign of VA deficiency (4, 5, 6, 7).
In one research, women with night blindness took vitamin A as food or supplements. Both sources of vitamin A improved night blindness by 50% in 6 weeks of treatment (8).
To preserve a healthy vision, it is essential to receive sufficient amounts of vitamin A from food. Night blindness is the first symptom of vitamin A deficiency.
Delayed Growth
Children not receiving enough vitamin A can experience stunted growth. This is because vitamin A is necessary to make the human body grow properly.
Several studies have shown that vitamin A can boost growth, alone or with other nutrients (9, 10, 11, 12).
However, most of these studies are performed on children (13).
A study found that vitamin A supplementation in combination with other nutrients may have a greater impact on growth than supplementation with vitamin A alone (14).
For example, children with stunted growth receiving multiple vitamins and minerals scores better than those receiving only vitamin A (15).
Acne
Because vitamin A stimulates skin health and battles inflammation, it can also prevent acne. Different studies show that low levels of vitamin A can increase acne (16, 17).
In one research of 200 adults, those with acne had 80 mcg vitamin, which was lower than those who did not have the disorder (16).
People can use it either topically or orally to treat acne. Research shows that vitamin A cream can reduce the number of acne lesions by 50% (18).
Isotretinoin is the most known source of oral vitamin A used for treating severe cystic acne.
This medication may be very effective in treating acne but may have several side effects, including changes in mood and birth defects (19).
Recurrent infections
Recurring infections can be a sign of vitamin A deficiency, especially in the throat or chest.
Vitamin A supplement can help with infections in the respiratory tract, but research results are conflicting.
Research in children found that underweight children taking 10,000 IU of vitamin A per week had fewer respiratory infections than those getting a placebo (20).
In another study in children, they found that excessive vitamin A may increase the risk of developing infections in the throat and chest by 8% (21).
The author of the study says, Vitamin A supplement is for those who are true deficit (21).
According to one study in older people, high blood levels of provitamin A can protect against respiratory infections (22).
Delayed Healing
Wound healing or delayed healing after injury or surgery have a close connection with low levels of vitamin A in the blood.
This is because vitamin A encourages collagen production, which is an important component of healthy ski (23).
Recent rat research has found that treating skin with vitamin A has proven to prevent diabetes-related wounds (24).
Research shows similar results in humans. Older men who treated wounds with vitamin A reduced the size of their wounds by 50% compared to men who did not use the vitamin A cream (25).
Infertility
Vitamin A is important for male and female reproduction and for proper growth in babies (26).
If you have trouble getting pregnant, one reason may be a lack of vitamin A.
Studies show that female rats with vitamin A deficiency are having difficulty getting pregnant, and may have birth defect embryos (26).
Some research suggests that infertile people may be more in need of antioxidants because of increased levels of oxidative stress throughout their bodies (27).
Vitamin A is one nutrient in the body which acts as an antioxidant.
The deficiency of vitamin A can also cause miscarriages. Research testing the blood levels of different nutrients in women with recurrent miscarriages showed they had low vitamin A level (28).
Dry Skin
Vitamin A is important for developing and repairing skin cells. It also helps reduce inflammation because of some skin problems (29).
Not having enough vitamin A could develop eczema and other skin problems (30).
Eczema is a swollen, itchy and inflamed skin condition. Alitretinoin, a prescription medication with vitamin A, was effective in the treatment of eczema in several clinical studies (31, 32).
In one 12-week study, people with chronic eczema who took 10–40 mg of alitretinoin per day observed a reduction of their symptoms by up to 53% (33).
However, dry skin can be a symptom of many conditions, but vitamin A deficiency may be one of those reasons.
Dry Eyes
Eye problems are among the most well-known symptoms of vitamin A deficiency. Sometimes, vitamin A deficiency can lead to complete blindness, called Bitot’s spots (34, 35).
One of the first symptoms of a vitamin A deficiency is dry eyes or the inability to produce tears.
Young children in India and Southeast Asia who have a vitamin A deficiency are at the highest risk of dry eyes (36).
Vitamin A supplementation may improve the condition. One study found that high doses of vitamin A decreased the symptoms of dry eyes by 63% in infants and children who were taking supplements for 16 months (37).
Side Effects of Too Much Vitamin A
Too much vitamin A can be dangerous. Excess vitamin A in the liver can cause toxicity and adverse symptoms, such as changes in vision, bone swelling, mouth ulcers, and confusion (38).
In particular, pregnant women should be careful not to eat or take too much vitamin A to prevent birth defects (39, 40).
Always consult with your health care provider before taking vitamin A or any other supplements. People with certain types of health can require a greater amount of vitamin A.
Most healthy adults, however, require 700–900 mcg daily. Females who nurse need more, while children need less (41).
Conclusion
Inflamed skin, night blindness, infertility, and respiratory infections can be the signs and symptoms of vitamin A deficiency.
Eat a variety of these foods to ensure you are receiving enough vitamin A.
Talk to your doctor or health care provider if you think you have a vitamin A deficiency.
