Vitamin A is essential for vision, the immune system, skin and growth. Its deficiency causes visual and immunological problems and its excess can be toxic. It is obtained from various foods and its supplementation must be borne by the specialized health professional once its deficiency or the health situation that supports this extra intake has been diagnosed. With the help of nutritionist dietician Amparo Bayarri, we reveal what vitamin A is for and what foods we find it in.
What is vitamin A, what types are there and why is it vital for your body?
Also called retinol or antixerophthalmic vitamin, vitamin A is a fat-soluble vitamin (it dissolves in fats or oils and is not eliminated in the urine like water-soluble vitamins), so its excess accumulates in our body. Vitamin A is involved in the formation and functioning of epithelial cells, bone growth, development and the protection and functioning of the skin and mucous membranes, among other vital functions.
Amparo Bayarri, dietitian-nutritionist and member of the Spanish Academy of Nutrition and Dietetics, helps us understand how many types of vitamin A there are: “Depending on its origin, we have preformed vitamin A (retinoids), the most abundant and active being retinol that comes from animal products such as fish, especially fatty ones, meat and organ meats, eggs or dairy products, and provitamin A (beta carotenes), which comes from plant products such as vegetables. leafy greens, intense orange fruits and vegetables, and tubers such as sweet potatoes. We must know that when we ingest preformed vitamin A or retinoids, the body absorbs it immediately, but if it is provitamin A, we need our body to transform it into vitamin A before it is used.”
And what is vitamin A for?, you may be wondering. Bayarri clarifies: «Vitamin A is necessary to cause a positive and beneficial effect on our body at the level of vision, the immune system and growth. In addition, it has an impact on good vision, especially for seeing in low light. On the other hand, it also contributes to the proper functioning of the immune system that maintains barriers against infections and, finally, contributes to the reproductive function and growth, since it is crucial for cellular and bone development.»
Where is vitamin A found? natural sources
We always say that the ideal is to have a healthy diet, where seasonal products play a major role, but, having said that, if you have a special interest in reinforcing the intake of certain specific nutrients, there are many foods with vitamin A that you should know about.
«Now,» Amparo clarifies, «although these foods are rich in vitamin A, we must keep in mind that we are talking about a fat-soluble vitamin, so it is advisable to eat it together with fatty foods for better absorption and metabolism, especially when its origin is plant-based.»
Top 10 foods with vitamin A that cannot be missing from your diet
The expert brings together the foods that contain the most vitamin A per 100 grams of product. In order from largest to smallest, they will be these:
- Liver and derivatives such as pâté
- turnip greens
- Carrot
- dried apricot
- Cabbages, chard and spinach
- sweet potato
- mango
- butter
- eggs
- Cheese
- red pepper
- Pumpkin
Fruits with vitamin A: Sweetness and nutrition in every bite
Among the fruits with vitamin A, mango, melon, persimmon, loquat and apricot stand out. This is stated by the consulted expert, who points out a curious key: «The yellow-orange color is responsible for the phytochemical that will give these benefits to the food, beta-carotenes. That is why, for example, carrots are the vegetables that contain the most carotenes and, therefore, they are the one that will provide us with the most vitamin A, but also cabbages, spinach, turnip greens, sweet potatoes, red peppers or chard are rich in this vitamin.»
Nutritional synergies: Benefits of combining foods with vitamin A and C
Vitamin C helps regenerate other antioxidants and protects tissues from oxidative damage, while vitamin A repairs cells. When we combine both, the benefits of vitamin A and C are especially interesting for the proper functioning of our immune system, so we must pay attention to taking them daily, varying the sources.
Deficiency and toxicity: How to maintain balance
Symptoms of vitamin A deficiency.
The symptoms are clear; Vitamin A deficiency can cause: night blindness (difficulty seeing in the dark), sensation of extremely dry eyes (xerophthalmia), dry, scaly skin and an increased frequency of respiratory infections. Before these symptoms occur, subclinical vitamin A deficiency is the most common and silent form of this deficiency: without visible symptoms, but with a real impact on the immune, reproduction and metabolism. Detecting it requires specific tests, since the usual analyzes may not be enough. Measuring retinol in the blood is the most accessible, although it has an important limitation: the body maintains stable levels until liver reserves are almost depleted, which can mask a real deficiency. For greater precision, retinol binding protein (RBP) is measured, although its interpretation is complicated in the presence of infection or infection, so combining it with prealbumin significantly improves diagnostic accuracy.
The dangers of excess vitamin A.
Someone may be wondering if there is any danger in consuming too much vitamin A. The answer is yes and the dietitian-nutritionist consulted explains it: «This is what we know as hypervitaminosis. Vitamins, like minerals, are essential elements that our body needs for its proper functioning, but the necessary quantities are small. An excess of vitamin A can present serious problems.»
And what would be the dangers of over-consuming vitamin A? «As it is a fat-soluble vitamin, the excess is stored in the liver and is not eliminated through urine. This can cause dizziness, headache, joint pain and, in serious cases, liver damage,» says the expert, who clarifies: «This usually happens when the excess occurs through taking supplements. It is very complicated that it occurs when we obtain vitamin A from food, except at times in the life cycle such as pregnancy, a state in which food sources high in vitamin A of animal origin should be avoided.»
Contraindications and important warnings
People with liver or kidney diseases should take note, as their case may be compromised by excessive consumption of vitamin A. On the other hand, excessive consumption of preformed vitamin A (retinol) has been linked to lower bone density in older adults.
Supplementation and daily consumption guide
What is the recommended dose of vitamin A according to age?
If the health professional recommends supplementation with vitamin A, the recommended dose of vitamin A according to Amparo Bayarri would be: in babies (0 to 12 months), 400-500 μg/day; in children from 1 to 8 years old, 300-400 μg/day and in adults, if it is a man, 900 μg/day and, if it is a woman, 700 μg/day.
Vitamin A Supplements: When Are They Really Necessary?
When in doubt, you should know that the doctor is always the one who determines whether there is a vitamin A deficiency after the clinical diagnosis. He is also the one who prescribes vitamin A supplements if necessary and under whose supervision they should be taken.
In basically active people, nutritional needs may vary depending on training and energy expenditure. You can expand information about vitamins for athletes.
Frequently Asked Questions (FAQ)
Does vitamin A help improve skin condition and acne?
Yes, vitamin A helps cell renewal and prevents pores from becoming clogged. In fact, medical treatments for severe acne (such as isotretinoin) are derivatives of vitamin A.
Is it true that eating carrots improves night vision?
Lack of vitamin A causes night blindness, so eating carrots or any other food source of vitamin A contributes to normal vision.
Can pregnant women safely take vitamin A supplements?
Vitamin A supplementation should be done only when necessary and under medical supervision. In pregnant women, high doses of preformed vitamin A (retinol) can cause congenital malformations in the fetus. Pregnant women should avoid high-dose supplements and excessive consumption of liver, obtaining their vitamin A mainly from vegetables (beta-carotene).
What is the earliest symptom of vitamin A deficiency in adults?
The most important symptom that we can perceive when there is a vitamin A deficiency is night blindness. If you notice that, when entering a movie theater or driving at night, it takes too long to adjust your eyesight or you see much less than others, there could be a deficiency of this vitamin.
How does cooking food affect the absorption of this vitamin?
Unlike vitamin C, vitamin A is quite resistant to heat. In fact, being a fat-soluble vitamin, lightly cooking carrots or spinach with a little fat (olive oil) improves the absorption of beta-carotenes, which are the precursors of vitamin A.
What is the relationship between vitamin A and collagen production?
Vitamin A stimulates fibroblasts, which are the cells responsible for producing collagen. This helps maintain normal skin function and heal wounds better.
Should smokers take special precautions with beta-carotene supplements?
Tobacco reduces vitamin A levels in the body, increasing oxidative stress. However, scientific studies have shown that beta-carotene supplements in high doses increase the risk of lung cancer in smokers and, therefore, taking them would be contraindicated. Smokers should get their vitamin A from the diet and avoid isolated beta-carotene supplements.
Amparo Bayarri. Director of the training area of the Spanish Academy of Nutrition and Dietetics. Professor at the University of Valencia, the Catholic University of Valencia and the Open University of Catalonia. Since 2020, he has run Bamay, a nutrition company for companies and entities, both public and private, focusing its services on the collective catering, training and public health sectors. Twitter: @a_bayarri Instagram: @a.bayarrimayo / @bamay_nutricion
