Vitamin A is an essential nutrient for our health.
The science is also clear that it’s best to get this vitamin from food sources.
Unfortunately, much of the global population—especially in developing countries—is deficient in this critical vitamin (1).
Perhaps more surprisingly, 51% of American adults are currently experiencing the same deficiency (2).
That’s more than one in two Americans who aren’t getting enough dietary vitamin A.
This article takes a look at what vitamin A does, the health benefits, and ten of the best low carb sources of the vitamin.
What Is Vitamin A?
Vitamin A is an essential fat-soluble vitamin.
It has great importance for our health and plays a critical role in vision, the skeletal system, the immune system, and reproduction.
Vitamin A comes in two different forms, and it can be either retinol (pre-formed vitamin A) or carotenoids (pro-vitamin A) (3).
The form depends on the food source;
- Vitamin A from animal foods is known as retinol (retinoids). This is an “active” bioavailable form of vitamin A, and our body can instantly utilize it in its natural form.
- Vitamin A sourced from plant foods contains beta-carotene (carotenoids), which is not an active form of vitamin A. The body needs to convert beta-carotene into retinol in order to use it.
Unfortunately, humans cannot convert carotenoids particularly well. Various studies show that the vitamin A conversion of beta-carotene can be extremely low and variable. Further, the conversion rate appears to drop as the ingested amount increases (4, 5, 6).
Therefore animal foods tend to be the best source of vitamin A (7).
It’s important to realize that vegetable sources of vitamin A require some dietary fat since it’s a fat-soluble vitamin.
Why Is Vitamin A Important For Our Body?
There are many important reasons why we need to consume sufficient vitamin A.
Firstly, vitamin A is necessary for proper utilization of protein and the production of growth hormones, including testosterone (8).
Another critical benefit of vitamin A is that it helps to protect and maintain optimal bone health. On this note, several studies show that even a moderate vitamin A deficiency impairs growth (9).
Regarding eyesight, vitamin A plays a significant role in protecting our eyes from damage.
In fact, vitamin A deficiency is often the first suspect when someone seeks medical advice for visual problems (10).
Another key point is that vitamin A plays an important regulatory role in the immune system, especially for babies and young children.
For example, the influence of vitamin A starts during pregnancy. Studies show that exposure to vitamin A in the womb strengthens lifelong immunity (11).
It is also important for young children to have an adequate consumption of vitamin A. To illustrate this, optimal vitamin A levels in children under 5-years old results in a considerable reduction in mortality, as well as decreased visual problems (12).
10 Foods High in Vitamin A
These ten foods are all rich in vitamin A, and they come from a variety of sources.
Some are animal-food sources, and others are plant foods which are high in the vitamin.
The foods are in no particular order, but number one just so happens to be the very best source!
1. Liver (17997 IU, 600% DV per 100g)
Liver is the richest source of vitamin A out of all foods.
Added to that, it’s one of the most nutrient-dense foods on earth.
Cooked pork liver provides 17997 IU Vitamin A per 100g, which is more than 600% of the recommended daily value (13).
Beef liver and chicken liver are also incredibly nutritious.
Sure, liver may not be the tastiest of foods, but it’s one of the healthiest.
Don’t like liver?
Then here are a couple of options;
- Fry some liver and onions; use butter, some herbs of your choice, and a touch of tamari soy sauce and red wine. Add some onions and garlic, and you have a delicious meal!
- Make some liver and bacon pate; using a food processor you only need three ingredients – butter, liver, and bacon. After forming a consistent paste, store the pate in the refrigerator for up to two weeks.
2. Eggs (520 IU, 17.3% DV per 100g)
The humble egg is an animal food rich in vitamin A, and there are so many nutrients in this small food.
Eggs provide 520 IU Vitamin A per 100g (approximately two eggs), which accounts for 17.3% of the recommended daily value (14).
Due to their impressive nutrient density, eggs are nature’s multivitamin and have far more going for them than just vitamin A.
There are so many ways you can make them too. Whether you prefer boiled, fried, poached or scrambled, all these options are healthy and delicious.
3. Sweet Potato (14187 IU, 473% DV per 100g)
One of the best vegetables for vitamin A is the sweet potato.
Sweet potatoes are one of the most nutrient dense sources of digestible carbohydrate.
They might not be good for strict ketogenic diets, but they’re an excellent fit for more liberal low carb/paleo diets and of course vegans.
While sweet potatoes are one of the best vegetable sources of vitamin A, they need fat for optimal absorption.
Spreading a bit of butter on them is one way to do this, or by eating them with an avocado or a few olives.
Sweet potato is a massive plant source of vitamin A, and 100g accounts for around 473% of the recommended daily value (15).
For those wanting a healthier upgrade, purple sweet potatoes (otherwise known as ‘Okinawan sweet potatoes’) are a great choice. For one thing, they are less sweet and much higher in polyphenols – especially anthocyanins.
4. Butter (2499 IU, 83.3% DV per 100g)
The previous food may have been a little higher in carbs, so now it’s time for a high-fat source of vitamin A.
Butter is high in vitamin A, providing 83.3% of the recommended amount per 100g (16).
As butter is an animal source of vitamin A and very high in fat, it is straightforward for our body to absorb the nutrient.
As a result, butter’s popularity is soaring, and it has won the “war” against margarine.
However, there’s one problem; when you go to the store, are you confused about which butter to buy?
Sneaky companies often try to disguise margarine as butter, so some people do make mistakes.
Lastly, while butter is a perfectly healthy food, this doesn’t mean we should add a stick of itto our coffee every morning!
5. Cod Liver Oil (100014 IU, 2000% DV per 100g)
While not technically a food, cod liver oil is a large provider of vitamin A.
With this, less is more, and just a teaspoon delivers a substantial serving of the vitamin.
However, that’s not all – cod liver oil also supplies a significant amount of vitamin D and long-chain omega-3 fatty acids.
Cod liver oil also has many documented benefits;
- Randomized controlled trials suggest that higher dietary intake of cod liver oil during early pregnancy leads to a healthier baby weight (19).
- Use of cod liver oil during early childhood appears to improve health and reduce the risk of diabetes and asthma (20, 21).
- Cod liver oil is potentially protective against glaucoma, the second highest cause of blindness in the world (22).
6. Spinach (9376 IU, 188% DV per 100g)
Spinach is one of the most nutrient-dense vegetables out there.
It is an especially significant source of vitamins A, C, K and folate, and 100g provides 188% of the recommended daily amount of vitamin A (23).
Again, I recommend combining it with something fatty (or adding a source of fat) to help with the absorption of fat-soluble vitamins.
A couple of recipes which help with this are spinach frittata and creamed spinach; both are simple to make!
For creamed spinach, just lightly fry some spinach in butter, and add salt, garlic, and black pepper.
Following this, add the desired amount of heavy cream and keep cooking for around 10 minutes while continuously stirring.
7. Tuna (2183 IU, 44% DV per 100g)
Tuna is the king of fish when it comes to vitamin A.
Some fresh bluefin tuna provides 44% of the recommended daily value per 100g (24).
On the downside, tuna does contain a significant amount of mercury, and the Environmental Working Group (EWG) advise to limit consumption.
Some assert that because tuna naturally contains more selenium than mercury, we don’t have to worry about the mercury content.
However, I haven’t seen any conclusive evidence of this and prefer to limit tuna consumption to one or two times per month.
Fresh tuna is the better choice for vitamin A, and canned tuna doesn’t offer the same benefits.
8. Kale (13623 IU, 272% DV per 100g)
Kale contains a significant amount of beta-carotene, and 100g provides 272% of the daily value of the vitamin (30).
Alongside spinach, kale is one of the most nutritious vegetables for vitamin and mineral content.
However, there is a hot trend for raw kale and pulverizing hundreds of grams of kale into vegetable smoothies has become a social norm.
Foods like kale and broccoli which can suppress the function of the thyroid gland in this way are known as goitrogens.
A little raw kale? No problem.
Large daily amounts? Maybe it’s not so good.
Cooking kale with a bit of butter is the best bet, as heat destroys many of these compounds. Additionally, buttered kale improves the absorption of vitamin A, and it tastes a whole lot better too!
9. Butternut Squash (11155 IU, 223% DV per 100g)
Butternut squash is another vegetable high in vitamin A and contains 223% of the recommended daily value per 100g (34).
We can use this vegetable in a wide variety of ways, from making soup to roasting it
Similar to spaghetti squash, it’s possible to use this vegetable to make some low carb noodles.
These ‘noodles’ are also a much healthier alternative to traditional pasta.
A butternut squash soup tastes great too, and it’s effortless to make. Firstly, mash some cooked squash and then combine it with heavy cream.
Add liberal amounts of black pepper, cook for about 10 minutes, and then it will be ready.
10. Carrot (16705 IU, 334% DV per 100g)
Carrots are extremely rich in beta-carotene, and they contain 334% of vitamin A’s recommended daily amount per 100g (35).
Carrots are a root vegetable which can come in many different colors.
While we usually see orange carrots, it’s also possible to find red, white, yellow, and purple carrots.
Should I Take Vitamin A Supplements?
Are vitamin A supplements the same as vitamin A from food?
Looking at various studies, it appears that the answer to this is no.
On the downside, vitamin A supplementation may potentially cause problems, with studies documenting the following effects;
- Vitamin A supplementation increases lung cancer risk in smokers (38).
- Synthetic vitamin A is ineffective for preventing mortality and is possibly harmful (39).
- In Africa, supplementation in pregnant mothers resulted in an increased mother-to-child HIV transmission or death (40).
These are just a handful of possible adverse effects from what is a long list.
All things considered, I think it’s much more beneficial (and safer) to get vitamin A from real food.
As shown in this list of foods high in vitamin A, there are many animal and plant sources of this nutrient.
Due to the unreliable conversion of pro-vitamin A into retinol, animal foods are the optimal choice.
However, fruit and vegetable sources of vitamin A are still beneficial to health.
Just be sure to eat them with a little fat to help increase the absorption of beta-carotene.