Ensuring adequate consumption of all of the essential vitamins and minerals is key to optimizing health. Vitamin A, a fat-soluble organic compound found in a variety of forms, is one such important vitamin.
As a rule of thumb, foods high in vitamin A are red or orange in color; think of bell peppers, sweet potatoes, turmeric, and carrots. Orange fruits and vegetables contain a compound called beta-carotene, which is converted to vitamin A in the human body. Therefore, these types of foods (orange fruits and vegetables) contain what is called “provitamin A.”
In this article, we’ll go over everything you need to know about vitamin A, including the importance of vitamin A and five specific benefits, vitamin A deficiency symptoms, vitamin A foods, and much more.
What is vitamin A?
Vitamin A is an antioxidant that helps combat free radicals, waste products that are continuously formed by various systems of the body. (8) Antioxidants, like vitamin A, help neutralize free radicals, reduce oxidative stress, and decrease cellular damage.
When stored in the blood, the most abundant form of vitamin A is retinol. Retinol is a form of vitamin A often used in skincare formulas to promote healthy skin cell formation and boost collagen production. Vitamin A is good for skin – often used as a treatment for acne and other skin conditions thanks to its antioxidant properties, and ability to reduce the mucous layer under the skin. (6)
Different kinds of vitamin A supplements
Vitamin A comes in two forms, the first is provitamin A, which is found in plant-based foods. The second type of vitamin A is known as “preformed” or “active” vitamin A1, which is found in meat and dairy. (7)
Vitamin A found in animal sources, often referred to as vitamin A1, contains retinoids, retinal, and retinoic acid. Retinoids are known as preformed or “active forms” of vitamin A, which means that they are bioactive and can be used by the body as they are. (7)
Provitamin A, found in plants, is referred to as the “inactive” form of vitamin A. This form is made up of compounds including alpha-carotene, beta-carotene, and beta-cryptoxanthin. (1)
Five health benefits of vitamin A
Let’s take a look at five key health benefits of vitamin A in more detail.
1. Enhances bone health
Consuming enough vitamin A is essential for bone health. Vitamin A influences the production of osteoblasts (cells that create new bone) and osteoclasts (cells that absorb bone tissue). People who have lower concentrations of vitamin A may have a slightly increased risk for bone fractures. (2)(29)
2. Supports skin health
Vitamin A has been used in some people suffering from acne. Vitamin A can help accelerate the elimination of sebum from the ducts of the skin thereby reducing inflammation in the sebaceous glands. Some medical acne treatments contain retinoids, which are compounds of vitamin A that help regulate skin cell growth. (28)
3. Optimizes reproduction and growth
Vitamin A plays a key role in reproduction and the formation of a healthy human fetus. Both male sperm production and female egg quality require adequate amounts of vitamin A for optimal fertility. (3)
4. Strengthens the immune system
Vitamin A reduces susceptibility to disease by optimizing the body’s natural immune defenses. Conversely, low levels of vitamin A may impair the function of the immune system thus increasing the risk of contracting an infectious disease. (26) Not only can low vitamin A impair the body’s ability to recovery quickly it can also increase the risk of death from diseases like malaria and measles. (22)
5. Improves eyesight
It’s no coincidence that the name retina, referring to the part of your eye that receives light, and retinol (vitamin A1) sound similar. Vitamin A is critical for healthy eyesight. Vitamin A helps protect the cornea, the surface of the eye, and it’s anti-inflammatory processes may play a role in decreasing vision loss from the deterioration of the central part of the eye (the macula). Beta-carotene may even prevent night blindness and slow the progression of age-related sight issues. (27)
How much vitamin A do you need?
The recommended daily value (DV) of vitamin A is 900 mcg for men, 700 mcg for women, and 300-600 mcg in children. (5) However, it’s important to note that excess vitamin A is deleterious to health. Be sure to speak to a healthcare practitioner before adding supplemental vitamin A to your wellness plan.
Discover foods high in vitamin A
A number of animal and plant-based foods naturally contain vitamin A. Eating a whole foods diet, filled with rich natural sources of vitamin A may be sufficient for most people. However, keep in mind that certain individuals may require supplementation, depending on their individual needs.
The following foods contain high levels of vitamin A and have been split into two columns – animal and plant-based foods.
Top five animal foods rich in vitamin A
Retinol (Vitamin A1) is found in animal foods. The top five animal foods listed below contain high amounts of retinol, in order of the highest amount of vitamin A to the lowest.
- Liver – beef (338% DV per 100g) (12)
- Cod liver oil (90% DV per teaspoon) (13)
- Bluefin Tuna (44% DV per 100g) (15)
- Mackerel (15% DV per 100g) (16)
- Salmon (2% DV per 100g) (17)
Top five plant-based foods rich in provitamin A
Listed in descending order, the top plant-based foods richest in provitamin A include:
- Sweet potato (284% DV per 100g) (20)
- Turnip Greens (232% DV per 100g) (21)
- Winter squash (213% DV per 100g) (19)
- Collards (100% DV per 100g) (13)
- Kale (96% DV per 100g) (18)
How much vitamin A is dangerous?
High doses of vitamin A supplementation can be dangerous, especially for pregnant women. Vitamin A supplements usually use preformed vitamin A and should be taken in under the supervision of a qualified healthcare professional. (23)
Excess intake of vitamin A may result in dry skin, headaches, dizziness, and vomiting. People with a substance use disorder, as well as those who take medications or have kidney or liver disease, should consult their healthcare practitioner before supplementing with vitamin A.
It’s important to note that too much provitamin A from plants will do you no harm. (11) From time to time, people will experience yellowing of the skin after consuming high quantities of provitamin A. Although aesthetically displeasing, this discoloration is not associated with any adverse health issues.
Symptoms of vitamin A deficiency
What happens if you don’t get enough vitamin A? Vitamin A is required for all of the systems of the body to work in harmony. As such, a deficiency can lead to the breakdown of different systems of the body. When the body is depleted of adequate vitamin A, the concentration of retinol in the blood will fall below 0.35 μmol/L (10 μg/dL). (4)
The main symptoms of vitamin A deficiency include:
Who is at risk of vitamin A deficiency?
Vitamin A deficiencies are rare in the US, but common in developing countries.
Some Asian populations are suffering from night blindness and increased child mortality rates due to severe vitamin A deficiencies. This phenomenon is rarely found in the west unless there are other underlying health conditions. (7)
Eating the standard American diet (SAD), leaky gut and digestive disorders can seriously reduce your body’s ability to absorb nutrients. As such a vitamin A deficiency can also occur in people with digestive disorders. (25)
The bottom line
The primary reason behind vitamin A deficiency is complications from another illness such as leaky gut, or following the standard American diet. In both cases, the body has trouble obtaining sufficient quantities of vitamin A. Vitamin A is abundant in a wide range of foods and can be obtained through the diet. However, each person is unique and there are many individuals with conditions such as acne, thyroid dysfunction, or eye diseases that may benefit from vitamin A supplementation. It’s advisable to consult with your integrative healthcare practitioner if you feel that you may benefit from additional vitamin A supplementation.
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