Many plant-based eaters are under the impression that they can obtain all the vitamin A that they need from plant foods that contain carotenoids, particularly beta carotene found in foods like spinach, sweet potatoes, and carrots.
It’s true that some carotenoids like beta carotene can be converted to vitamin A in your body once they make it into your blood. What you may not know is that carotenoids are not always absorbed efficiently into your blood.
Given that vitamin A deficiency is one of the most common nutritional deficiencies in the world and is also a leading cause of death in young children, it’s critical for the general public to know that relying solely on carotenoids in plant foods for daily vitamin A needs may lead to any of the following health problems over time:
Skin Lesions Like Acne and Acne Rosacea: Vitamin A is needed to develop and maintain moist and healthy epithelial tissues, including your skin. Many long time vegans find it difficult to understand why they have acne while on a whole food, plant-based diet. Vitamin A deficiency is undoubtedly a common cause of acne for all acne sufferers, but particularly for people who eat mainly a plant-based diet and don’t include a reliable source of vitamin A in their diets.
Poor Night Vision: Vitamin A combines with a protein in the back of your eye to enable night vision.
Weak Bones, Weak Teeth, and Poorly Spaced Teeth: Vitamin A is needed for proper growth and maintenance of bones and other soft tissues throughout your body.
A Weak Immune System: Because vitamin A is needed for the development and maintainance of all of your body’s barriers to infection like your skin, lungs, and the mucosal linings in your digestive and urinary tracts, a deficiency almost assures you of an immune system that is not as strong as it can be.
Cancer: Since vitamin A is essential to the health of your immune system, a deficiency could increase your risk for developing certain forms of cancer, such as breast, lung, stomach, and cervical cancer.
Anemia and Associated Fatigue: Vitamin A is needed for proper red blood cell formation.
Vitamin A is actually a group of compounds that includes retinol, retinal, and the carotenoids. Retinol and retinal are found in animal foods such as liver, eggs, and butter. Because these forms of vitamin A are ready to be used by your body straight from their food sources, they are often referred to as pre-formed vitamin A.
Carotenoids, in turn, are often referred to as provitamin A since they are precursors to Vitamin A and need to be converted in your body.
The total vitamin A in your diet is therefore a combination of the pre-formed vitamin A and provitamin A in your diet.
It’s important to note that optimal absorption of retinol, retinal, and the carotenoids into your blood requires an adequate amount of healthy fat in your diet. This is because pre-formed and provitamin A are fat soluble compounds that are best absorbed into your blood in the presence of digestive juices that are needed to digest fat. The more healthy fat you include in your diet, the better you will absorb fat soluble vitamins A, D, E, and K into your blood.
I don’t believe it’s practical to offer a chart that lists specific amounts of useable vitamin A in different foods because the amount of vitamin A that ultimately reaches your blood depends on the variables described above.
So, here are two simple lists of healthy foods that contain significant amounts of pre-formed and provitamin A. I believe that it is best for most people to eat foods from both groups on a regular basis to to meet their daily vitamin A needs.
Pre-formed Vitamin A:
- Organic beef liver
- Organic lamb liver
- Organic eggs
- Organic butter
- Cod liver oil
- Sweet potatoes or yams
- Butter nut squash
What About Toxicity?
With the exception of cod liver oil, all of the other foods listed above have virtually no potential to cause vitamin A toxicity in your tissues. So long as you stick to an appropriate dose of cod liver oil, you can rest assured knowing that you aren’t getting too much vitamin A each day.
Every study that I have looked at that discusses the potential for vitamin A toxicity looked at synthetic sources of vitamin A. Clearly, it is best to get vitamin A from the healthy foods listed above and to avoid synthetic sources at all times.