It is interesting to identify how increasingly unaware we grow of our dietary necessities. Moreover, being a vegan entitles one to the risk of several deficiencies including Vitamin A. Most of us don’t even know that there are prominent distinctions between non-vegan sources of Vitamin A and plant-based vitamin A, the former being more potent and the latter being safer.
Do you know how do vegans get Vitamin A and if the concentration is adequate? Indeed, there are several vegan foods, high in vitamin A, but not in the active form. However, their absolute exclusion from our dietary practices can cause severe health conditions.
Let’s get to know our dietary friend Vitamin A more and understand if the vegan sources of Vitamin A are reliable or we need to supplement our diet for reducing the risks of deficiencies.
What is Vitamin A and Why is it Essential to the Human Body?
Vitamin A is an overarching micronutrient that includes a group of fat-soluble compounds, namely retinol, retinal, and retinyl esters. The two crucial forms of vitamin A found in the human diet are preformed vitamin A (retinol, retinyl esters), and provitamin A carotenoids.
The preformed vitamin A occurs significantly in animal products, such as dairy, eggs, liver, and fish. Whereas, provitamin A carotenoids are abundant in plant foods like fruits, vegetables, oil, etc where they are converted to retinal and retinoic acid, the active forms of the vitamin, to be absorbed by the body. Beta-carotene is the primary plant-based source that gets converted to retinol for absorption.
It is important to note that vitamin A is fat-soluble, therefore, it’s stored in body tissue or liver for later use. Vitamin A is vital for the human body and health. They support cell growth, immune function, fetal development, and vision. The active form of vitamin A, retinal, forms rhodopsin with protein opsin that is central to color vision and low-light vision. It also helps protect the cornea and the conjunctiva, securing the health of the surface and within your eyelids. Vitamin A maintains the surface tissues in the skin, intestines, lungs, bladder, and inner ear. It assists immune function, supporting the growth as well as the distribution of T-cells, a kind of white blood cell that defends the body against infection.
What is the Daily Recommended Intake of Vitamin A?
The Recommended Dietary Allowance of Vitamin A for adults, who are 19 years and older, is 900 mcg RAE for men (equivalent to 3,000 IU) and 700 mcg RAE for women (equivalent to 2,333 IU). It is worth understanding that RAE stands for “Retinol Activity Equivalents’ ‘, in which the need for Vitamin A is reported and measured as a common unit for both preformed vitamin A and provitamin A carotenoids. Newer research, taken into account, established that on average, it takes 12 mcg of beta carotene ( the major plant-based source of Vitamin A) to produce 1 mcg of vitamin A.
That is, 12 mcg beta carotene = 1 mcg vitamin A = 1 RAE
The Tolerable Upper Intake Level or the maximum daily intake for vitamin A from retinol is 3,000 micrograms of preformed vitamin A.
The Vegan Diet, Beta-Carotene, and Vitamin A
Vitamin A is an essential nutrient for the proper functioning of the body. As we have discussed previously, the Preformed vitamin A is exclusively found in animal products. This type of Vitamin A is not available in vegan food options unless the food has been bioengineered or fortified with the same. From a plant-based diet, our body can utilize about 50 provitamin carotenoids and convert them into vitamin A, with the most common being beta-carotene.
While Vitamin A is measured in food using RAE, the carotenoids are measured in international units or IU.
- 1 IU beta-carotene from food= 0.05 micrograms RAE
- 1 IU beta-carotene from dietary supplements = 0.15 micrograms RAE
However, the consumption of vegetables high in carotenoids, with some fat to facilitate its absorption, can improve the synthesis of vitamin A. It’s possible to meet the RDA of vitamin A from beta carotene alone, but it requires a deeper understanding of whether or not the food on your plate serves enough Beta-carotene or not!. Other factors such as body composition, age, smoking, medications, alcohol consumption, food processing, and genetic variation determine the efficiency of absorption and conversion of dietary carotenoids to vitamin A.
There are two reasons why vegans may encounter a deficiency of Vitamin A:
- The lack of adequate concentration of carotenoids in the diet.
- The lack of generous amounts of leafy green vegetables, carrots, sweet potatoes, and bright orange winter squashes in food habits.
- The issue of lower absorption.
Symptoms of Vitamin A Deficiency in Vegans
Preformed vitamin A is more readily absorbed and utilized by your body than plant-based sources of provitamin A carotenoids. Therefore, most vegans might be deficient in Vitamin A, which may reflect through the following risks:
- Night blindness
- Irreversible blindness
- Lower immunity
- Vulnerability to death from measles and diarrhea
- Increased risk of anemia and death in pregnant women
- Hindered fetal growth and development
- Skin issues like hyperkeratosis and acne
Since our body composition and genetics play an important role in our utilization of Vitamin A, certain groups such as premature infants, patients of cystic fibrosis, and pregnant or breastfeeding women may develop the chronic risk of vitamin A deficiency.
How to Incorporate Enough Vitamin A in a Plant-Based Diet?
There are many dietary sources of provitamin A carotenoids. However, your body’s efficiency in converting carotenoids into active vitamin A depends on many factors such as genetics, diet, overall health, and medications. Low absorption tendencies can also be mitigated by increasing the carotenoid-rich food in dietary patterns.
|Food and Serving Size||RAE|
|Sweet potato (1/2 C baked)||961|
|Carrots (1/2 C boiled slices)||665|
|Carrots (1 whole, raw, medium)||509|
|Butternut squash (1/2 C baked cubes)||572|
|Acorn squash (1C baked cubes)||45|
|Pumpkin (1/2 C canned)||953|
|Bell peppers, green, raw (1 C slices)||17|
|Bell peppers, red, raw (1C slices)||153|
|Apricots (1/2 C dried)||117|
|Apricot (1 whole, raw)||34|
|Cantaloupe (1 C chunks)||270|
|Mango (1 C pieces)||89|
|Collard greens (1/2 C cooked)||386|
|Kale (1/2 C cooked)||86|
|Spinach (1/2 C cooked)||472|
|Broccoli (1 C boiled)||120|
|Carrot juice (1/4 C)||564|
As the list must clarify, it’s possible to meet the daily intake requirements for Vitamin A from plant-based foods.
Should Vegans Supplement with Vitamin A?
If the dietary sources fail to deliver the necessary Vitamin A to you, it should be advisable to go for vitamin A supplementation. There is generally a higher possibility of getting Vitamin A from plant sources, which is why Vitamin A supplementation is rarely required. Moreover, our body can store Vitamin A in the liver and beta carotene in fat tissues which kicks out any possibility of the lack of availability of the micronutrient. As an exception to the generalization, one might have lower absorption capacities for Vitamin A, where a slightly greater dose might help the body get the required amount.
It is advisable to seek a doctor’s advice in the matter and seek a recommendation. Alarmingly, there is a high potential for toxicity and harmful side effects upon Vitamin A overdose. Since the preformed Vitamin A is stored in the liver, the excess of it can be toxic. Whereas for beta carotene from natural food sources, our body controls the conversion of it to Vitamin A and takes up only the necessary amounts. Therefore, it does not pose a threat of toxicity. Yet, if taken from a concentrated supplement, beta-carotene may be harmful to some people for various other reasons.
Verdict | Can Vegans Get Adequate Vitamin A from Plant-based Foods?
There’s no naturally-occurring preformed vitamin A in vegan diets, It’s sometimes introduced into vegan foods through fortifications by using plant-based kinds of milk or margarine. If you don’t consume modified or fortified foods as a vegan, your chief source of Vitamin A shall be Pro-Vitamin A. The greatest benefit of consuming carotene-rich food is that it neither causes the deficiency of Vitamin A nor leads to a potential risk of toxicity like preformed Vitamin A.
To ensure that you are adequately meeting the RDA, try to incorporate at least one serving of leafy green vegetables per day or consume orange vegetables like sweet potato, carrot, butternut squash, or pumpkin every day.