Vitamin A deficiency: levels, symptoms, how to treat
LAST UPDATED: Oct 27, 2021
4 MIN READ
HERE'S WHAT WE'LL COVER
We all know the importance of getting enough vitamins and minerals in our diets, but some are easier to get than others. Vitamin A is one of those nutrients most of us don’t have to worry about being deficient in since it’s available in so many foods.
And, indeed, vitamin A deficiency has become much less common in areas with good access to food. Still, it’s a major public health concern in developing countries and low-income areas, where the prevalence of vitamin deficiencies and malnutrition is higher. In addition, some health conditions may increase your risk for a vitamin A deficiency even in places with good access to food.
This article covers what a vitamin A deficiency is, the symptoms, and how to treat it.
What is vitamin A?
Vitamin A helps support vision, bone health, cell growth, skin, and infant development. It’s a fat-soluble vitamin found in a variety of foods. There are two forms of vitamin A found in foods, provitamin A and preformed vitamin A (Chea, 2021).
Both types are converted in the liver and intestines so the vitamin A can be used by the body. Extra vitamin A can be stored in the liver and fat tissue to be used later.
Preformed vitamin A, known as retinoids (retinal, retinol, retinoic acid), is found in animal livers, meat, fish, and eggs. You might also recognize the term retinoids from skincare products, but that’s a topical form of this substance.
The other type of vitamin A is found in plant foods in the form of carotenoids, like beta-carotene. Carotenoids provide the orange pigment in foods. Plant foods high in vitamin A include carrots, cantaloupe, red bell peppers, sweet potato, green leafy vegetables, and apricots.
What is a vitamin A deficiency?
A vitamin deficiency occurs when there isn’t enough of a vitamin in your body for healthy function. Deficiencies can develop from:
Not eating enough vitamin A in your diet
Problems converting vitamin A to its active form
Trouble absorbing vitamin A from foods or supplements
In most developed countries, like the United States, vitamin A deficiencies caused by lack of nutrition are rare. A wide variety of foods contain vitamin A naturally, while others, like dairy products and cereals, may be fortified with extra vitamin A to prevent deficiencies.
In some developing countries, vitamin A deficiencies caused by poor nutrition still do occur.
People with some health problems are at a higher risk for vitamin A deficiency because these conditions impact the body’s ability to absorb and use vitamin A. Medical conditions that may lead to vitamin A deficiency include (Hodge, 2021):
Gastrointestinal conditions, like inflammatory bowel disease and Crohn’s disease
Bile duct disorders
Gastric bypass surgery (bariatric surgery)
People at a higher risk for a vitamin A deficiency include young children, pregnant women, and breastfeeding women.
Vitamin A deficiency symptoms
While you’re unlikely to develop a vitamin A deficiency, some signs and symptoms to watch out for include (Hodge, 2021):
Night blindness, also known as nyctalopia, is trouble seeing in dim lighting or at night. Severe vitamin A deficiencies could result in complete blindness in low lighting. One of the early signs of night blindness is trouble adjusting from a well-lit room to a room with low light.
Increased infection risk
Vitamin A supports the immune system by helping your body grow new immune cells. Someone with vitamin A deficiency may experience more frequent or longer-lasting infections.
People with vitamin A deficiencies are more likely to experience dry, itchy, irritated, and scaly skin.
Xerophthalmia is a condition that develops from vitamin A deficiency where the eyes become dry and crusted. Severe dry eyes can damage the retina and cornea. Left untreated, this may lead to vision changes or blindness.
Fertility and pregnancy problems
One of the major functions of vitamin A is to support cell division and growth. A side effect of vitamin A deficiency is difficulty conceiving. Vitamin A also helps babies grow quickly, develop their immune system, and develop healthy vision.
Stunted growth in children
A lack of vitamin A can stunt growth by causing slower bone development and delaying growth spurts.
Bitot spots are spots that form in the whites of the eyes. They can be triangular, oval, or irregular in shape, and they’re caused by the buildup of keratin (fibrous tissue) on the surface of the eye or in the conjunctiva (the clear layer that covers the eye). The spots develop from the drying of the cornea and may lead to hazy vision.
Poor wound healing
For wounds to heal, cells need to divide and grow to replace injured cells. A vitamin A deficiency may make it more difficult for wounds to close and your body to replace the damaged cells.
Keratomalacia is an eye condition where the cornea softens and becomes cloudy. This condition usually develops after prolonged dry eye and in severe vitamin A deficiencies.
More severe deficiencies may lead to the keratinization or hardening of the eyes or other tissues.
Vitamin A deficiency test
If you’re showing signs of a vitamin A deficiency, your healthcare provider will likely start by reviewing your medical history, completing a physical exam, and examining your eyes. If they suspect a vitamin A deficiency, they’ll order blood work to measure vitamin A levels in your blood.
Vitamin A deficiency treatment
More often than not, vitamin A deficiencies can be corrected by eating more foods rich in vitamin A. Vitamin A supplementation may be used to correct the vitamin A deficiency quickly. Some symptoms of vitamin A deficiencies will improve with adequate amounts of vitamin A.
The recommended dietary allowance (RDA) for vitamin A is around 700–900 mcg (2,300-3000 IU) per day for most adults (Hodge, 2021).
If vitamin A deficiency symptoms don’t improve with diet, your healthcare provider may do further testing to look for conditions that may be causing your deficiency and may recommend a vitamin A supplement.
Doses of vitamin A supplements shouldn’t exceed 10,000 IU per day in pregnant women since too much vitamin A can harm a fetus.
How to prevent a vitamin A deficiency
Since many foods with vitamin A, like fruits and vegetables, are primarily carbohydrates, it can help to pair these foods with healthy fats. Fat-soluble vitamins like vitamin A need some fat to absorb properly into the body. The best way to prevent a vitamin A deficiency, or any nutrient deficiency, is to eat a diet full of a variety of foods. Try to eat a wide range of fruits, vegetables, whole grains, healthy fats, and lean proteins. This helps ensure you’re receiving all of the different micronutrients your body needs.
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
Chea, E. P., Lopez, M. J., Milstein, H. (2021). Vitamin A. [Updated 2021 Jul 25]. In: StatPearls [Internet]. Retrieved on Oct. 18, 2021 from https://www.ncbi.nlm.nih.gov/books/NBK482362/
Hodge, C. & Taylor, C. (2021). Vitamin A deficiency. [Updated 2021 Jul 27]. In: StatPearls [Internet].. Retrieved on Oct. 18, 2021 from https://www.ncbi.nlm.nih.gov/books/NBK567744/