by MARNIE WILLMAN, MEDICAL/SCIENTIFIC COMMUNICATOR, BSC
What is vitamin A?
Vitamin A is an essential micronutrient that we humans cannot live without (1).
Our bodies cannot manufacture vitamin A, so we have to get it from the foods that we eat instead.
Vitamin A is required for surface tissue (like your skin) strength, mucous production (which can prevent infection), healthy immune system maintenance, and reproduction (2).
Our bodies need vitamin A to function properly, and this all comes down to diet!
Most of these fruits and vegetables contain Vitamin A. But which have the most?
(If you’re looking for more information on healthy fruit, see our “10 Healthy Fruits” article; for info on vegetables, click here)
Vitamin A deficiency and current interventions
Malnutrition remains a problem for many populations, and as a result, vitamin A deficiencies are common in developing countries.
It has been estimated 5–10 million children globally develop night-blindness and other problems as a direct result of vitamin A deficiency each year (3).
Many non-profit aid groups have been involved in trying to improve this problem.
Some interventions such as golden rice (which is modified to contain higher vitamin A levels than regular rice (4)) may be the solution in these difficult circumstances.
Golden rice (modified to contain higher vitamin A levels) has been a significant step forward in increasing vitamin A intake in countries that are chronically deficient. To see more healthy rice varieties – see our Healthiest Rice article.
In addition, an attempt to reduce the problems related to vitamin A deficiency has been to increase consumption of fruits and vegetables that are naturally high in vitamin A.
For example, Guatemala has been identified as a country with a chronic vitamin A deficiency problem, particularly among children.
Sweet potato can be grown in this region with few problems and high yield and has been proposed as a solution to the deficiency issues.
Particularly in young children, this vegetable may increase vitamin A, reducing the health problems that an early shortage incurs later in life.
Vitamin A has other names: Beta-carotene and provitamin A
Beta-carotene is the reason why you were always told to eat your carrots. Look for that orange color, and there you find beta-carotene!
But, beta-carotene (also called provitamin A) is actually converted (metabolized) into vitamin A after it’s eaten (5).
However, don’t overdo it on this helpful vitamin! Vitamin A overdose is thought to cause some unpleasant side-effects (6).
Instead, stick to your recommended 900 micrograms for an adult per day (7).
Orange-colored vegetables like carrots, squash, and even sweet potatoes have high levels of Vitamin A.
In Western societies, the majority of vitamin A intake comes from animal products (such as eggs and dairy products (8)), but it can come from plants, too!
When it comes to plants, green leafy vegetables, and orange fruits and vegetables are the key to finding this vitamin.
When you eat these foods, you either get dietary vitamin A (direct), intestinal absorption (as the food travels through your digestive system), or metabolic activity (which converts beta-carotene to vitamin A) (9).
Altogether, these systems help us get all of the vitamin A we need to keep our body running.
Health benefits of Vitamin A
Prevent cancer
Lung cancer causes 29% of all cancer deaths and 6% of all deaths in the United States (10).
Fueled by pollution, cigarette smoke, and other unhealthy environments, cardiovascular diseases like lung cancer have increasingly become a problem.
It was initially hoped that vitamin A would reduce these risks.
Still, studies have now shown that vitamin A supplements (beyond normal levels obtained through a healthy diet) have no effect on lung cancer risk, and can, in fact, make the condition worse (11).
However, vitamin A has been shown to reduce the risk of some types of cancer including prostate cancer (12).
Further studies are needed to solidify this concept.
Beta-carotene has also been recommended for the prevention of cardiovascular disease in general, although in light of recent studies, this practice is under scrutiny (13).
Prevent macular degeneration
Macular degeneration is a disease of the eye that occurs naturally as we age (14).
The central area of our eye (called the macula) controls our ability to read, recognize faces, drive, and essentially see.
As we get older, this part of the eye breaks down, and general wear through the years reduces our ability to see.
In fact, macular degeneration is one of the most common reasons why people lose their vision as they get older (15).
Carotenoids (including beta-carotene, later vitamin A) can be converted to retinol (16), which can reduce macular degeneration.
Vitamin A also acts as an antioxidant (17), which can improve eye health, preventing conditions such as eye cancer and tumors.
Macular degeneration is the number one reason why people lose their sight over time.
Prevent virus-related morbidity and mortality
Viral diseases continue to ravage countries around the globe.
For example, measles is a disease characterized by spots and a rash, watery eyes, runny nose, high fever, and cough (18).
Measles infections kill approximately 2 million children each year, and the disease is made worse by vitamin A deficiency, which often occurs in the same regions.
While vaccines and antivirals are available in developed countries, these medicines do not reach everyone, and developing countries continue to grapple with viral infections.
The World Health Organization (WHO) is one of many groups tracking global measles outbreaks, which are made worse by vitamin A deficiencies.
A 1990 study looking at measles in children found that death and severity were reduced in those children who received enough vitamin A, while those who were deficient suffered worse outcomes (19).
Other studies have also found the importance of vitamin A in warding off measles, and have attested to its usefulness in fighting viral infections (20).
Potentially reduce fracture risk
A 2004 study examining postmenopausal women and the health effects of vitamin A revealed some interesting results (21).
Postmenopausal women are at higher risk of bone fractures because low estrogen levels accelerate bone density loss.
That is, the bones don’t build themselves back up at the same speed because estrogen levels have decreased, resulting in weaker bones (22).
This study showed that, while excessive vitamin A can weaken bones and cause osteoporosis, there was a slight increase in bone health in those receiving a moderate amount of vitamin A through their diets.
However, researchers remain unclear on whether this is evidence of vitamin A reducing hip fractures in older women.
The effect was slight and only in some groups, but the question of bone health and the impact of vitamin A continues to be the subject of ongoing research.
Reduce cholesterol in obese populations
Preliminary studies have been completed looking at the effect of vitamin A on cholesterol levels of obese rats, which model human metabolism and bodily functions.
Feeding obese rats vitamin A in their diet resulted in lower blood cholesterol levels (reducing overall cholesterol) (23).
While the mechanism behind this remains unknown, vitamin A could prove to be a useful cholesterol management tool and is currently under investigation.
Lowering cholesterol improves overall health by reducing the risk of cancer, heart disease, and cardiovascular disease (24).
*Infographic free to include on your site with link
Top 10 Foods High in vitamin A
1. Carrots (purple or orange!)
Eat your carrots, and you’ll have healthy eyes!
This actually goes for the purple variety in addition to traditional orange carrots.
Carrots are a great source of beta-carotene, which later becomes vitamin A.
The bioavailability of beta-carotene in carrots, relative to other vegetables, is reasonably high.
(19–34% of the total vitamin A content is absorbable by your body (25)), which makes them an ideal source!
An added benefit to purple carrots is that they have a high phenolic content, in addition to beta-carotene (26).
Phenolic compounds can fight off diseases like cancer, diabetes, chronic inflammation disorders, metabolic disorders, and a host of other potential health problems.
2. Butternut Squash
Butternut squash (like carrots) has that tell-tale bright orange color that indicates a vitamin A goldmine.
In fact, one cup of cooked butternut squash contains 450% of your daily recommended value of vitamin A (27).
You wouldn’t want to overdo it on this healthful veggie (risking a vitamin A overdose), but it can boost your vitamin A levels up if you’re deficient, and help you maintain a healthy daily intake.
Particularly for vegetarians who tend to be low in vitamin A, this brightly colored squash could be your knight in shining armor.
In addition to vitamin A, this squash also has 50% of your daily recommended dose of vitamin C per cooked cup, lots of fiber (to help lower your cholesterol), and plenty of antioxidants to prevent disease (28).
All in all, this makes a great addition to your dinner plate, in moderate quantities.
3. Sweet Potato
As mentioned in the introduction, sweet potatoes have been a proposed solution to vitamin A deficiency facing many developing countries.
Orange or white-fleshed sweet potato is a vegetable that can grow in harsh conditions and reduce deficiencies effectively, being very high in beta-carotene (containing 100-1600 micrograms per serving, depending on the variety (29)).
4. Pistachios
After covering three orange foods, I’ve caught you by surprise!
Containing a healthy dose of vitamin A (278.05 micrograms per serving), pistachios are also a great source of vitamins E and C, and several B vitamins (30).
Additionally, pistachios have potassium, phosphorous, magnesium, calcium, and a variety of other nutrients required for normal cell and body functions.
This powerhouse of nutrients should absolutely be part of your diet, and will provide a healthy dose of vitamin A among many others!
5. Spinach
Spinach in extremely high in vitamin A, and that dark green color shouldn’t convince you otherwise.
Just one cup of this leafy green (cooked) contains a whopping 943 micrograms of vitamin A (31), more than the recommended daily allotment.
Spinach has also been credited with a reduced risk of breast cancer, although vitamin A alone has not been associated with this reduction (32).
Researchers are examining how micronutrients in spinach complement each other, as this could be the reason behind this effect, but the results aren’t in yet!
It is interesting that this effect is seen in carrots as well, which are also high in beta-carotene but stay posted for more details on this particular topic.
6. Cantaloupe
Cantaloupe brings us back to that orange color, and is high in provitamin A and vitamin C.
As a comparison, cantaloupe contains up to 60 times more beta-carotene than honeydew melon (33). If you’re looking for vitamin A, look no further!
The other great quality about melon is that it’s eaten raw.
Beta-carotene and other vitamins and nutrients often break down during the cooking process of some vegetables and fruits, making cooked produce a less nutritious choice (34).
Cantaloupe is eaten raw and as it is, meaning you get the full benefit of that vitamin A content.
The catch with cantaloupe is that few of us grow them in our backyard, and the majority of them are imported from California in the United States (35).
Depending on when the cantaloupe was harvested and the growing conditions of the farm, the beta-carotene quantity can change.
However, this should not dissuade you from eating this vitamin A-, vitamin C-, and water-packed fruit as part of a healthy diet.
7. Mango
There have been arguments between research findings when it came to vitamin A content in this slippery orange fruit for quite some time.
As it turns out, there is vitamin A in the pit and in the pulp, and the differences were coming from whether they were counted together, or separately!
It seems a bit funny to include the pit in our nutritional discussion because we don’t eat that part of the fruit.
The pulp of mango is high in beta-carotene, containing 661.27–2,200 micrograms of vitamin A (36), depending on growing and harvesting conditions.
Like all fruits and vegetables, eating raw mango when possible ensures you maximize the nutritional benefits, which can be lost during cooking.
This fruit also contains vitamin C, phenolic compounds (potent antioxidants and disease crime-fighters), and a host of other powerful nutrients (37).
8. Lettuce
This is another green leafy vegetable that is high in vitamin A (38) (despite its color), and has the same nutritional benefits as cantaloupe, in that it’s eaten raw.
Raw lettuce contains approximately 133 micrograms of vitamin A per cup. It’s less concentrated than other sources previously listed, but noteworthy nonetheless, and certainly provides many other nutrients.
The primary complaint about lettuce is that levels of light and other growing conditions have a much greater impact on nutrients than previously thought (39), so it’s important to know where your lettuce has come from.
That said, it’s a great addition to your diet, containing a variety of antioxidants, polyphenols, and vitamins (primarily A and C).
9. Bell Peppers
Bell peppers of all colors are a good source of many nutrients, including vitamins B6, C, and A, folic acid, beta-carotene, and fiber (40).
Studies into the usefulness of beta-carotene from bell peppers suggest that it has a powerful antioxidant effect, which prevents a myriad of diseases (41).
Bell peppers also contain ascorbic acid, flavonoids, and other nutrients that are essential for health.
Better eaten raw to maximize nutrient content, this tangy vegetable can provide you with a variety of nutrients to nourish your body.
10. Broccoli
Broccoli is lower in vitamin A, containing approximately 120 micrograms per cup (cooked), but still a good source of this healthful nutrient.
One problem with broccoli is that it’s usually cooked for quite some time, reducing the nutrient content.
Beta-carotene, in particular, hasn’t been studied.
Still, researchers have shown that handling before and after harvest, growth conditions, and cooking conditions have the potential to lower the beta-carotene content of this vegetable (42).
Frozen vegetables compared to fresh didn’t lower the beta-carotene content (43), but cooking did.
Where else is vitamin A hiding?
One of the easiest places to find this essential nutrient is probably sitting in your fridge.
The beta-carotene (which later becomes vitamin A) in butter is what gives it its natural light yellow color (44).
While the amount of vitamin A differs between sources, butter is an excellent place to start when it comes to vitamin A.
(Of course, from a health standpoint, you shouldn’t be eating copious quantities of butter; but a little is part of a healthy diet, and can boost your vitamin A levels).
To learn more about healthy forms of dairy (particularly milk), see our “Healthiest Milk” article.
Egg yolks and butter are other sources of vitamin A that you probably already have at home.
Vitamin A is also in eggs.
Again, remember that the yellow/orange color of yolk matches our description of yellow/orange foods containing high Vitamin A, bananas, corn, cod liver oil, mustard greens, turnips, alfalfa, and so many other foods (45).
It’s important to remember that while we’re covering the top 10 fruits and vegetables containing vitamin A (or beta-carotene), this list is far from exhaustive.
Stick to your foods with natural orange or yellow colors and dark green, leafy vegetables, and you’ll be in the right place!
A Brief Recap: What We Learned about Foods High in Vitamin A
In this article, we’ve covered some of the cleanest sources of high vitamin A that fruits and vegetables can offer.
This shows the importance of having a varied diet with many sources of nutrients, instead of sticking to the usual choices at the grocery store.
Vitamin A is an essential nutrient that adults and children around the world are deficient in.
Vitamin A deficiencies lead to blindness, skin problems, viral infections, organ failure, reproduction problems, and many other health issues.
Something that few people know to look for when searching for vitamin A is that this nutrient is also frequently referred to as “beta-carotene” or “provitamin-A”, depending on the source.
All three of these names are metabolized by your body into vitamin A.
When getting your daily dosage, ensure you don’t go too overboard with vitamin A, as this can cause some complications, including bone density loss, liver damage, migraines, joint pain, birth defects, and nausea.
Making sure you have a healthy diet takes some work!
Reading about what your recommended allotment of vitamin A is and estimating (based on the foods you eat daily) what you’re getting is essential.
So read on! Learn more about vitamin A and other essential nutrients that your body needs and are far too easy to miss in a typical modern diet.
This article is a great start! Good luck on your journey to becoming an even healthier you.