To stay healthy and perform at our peak, our bodies need lots of different nutrients, vitamins, and minerals. Some of them – like iron and magnesium – we might be pretty familiar with, and others, like CoQ10, we might never have heard of.
There are also many nutrients that we might know are important, but still aren’t quite sure what they do, or why they’re so vital. One of these nutrients is vitamin A.
So what exactly is vitamin A? Why is it important to our health, and how can we make sure we’re getting enough of it? Here’s everything you need to know about vitamin A.
What is vitamin A?
Though we often tend to view vitamin A as one single nutrient, it’s actually a generic term for a group of fat-soluble compounds (including retinol, retinal, and retinyl esters) that our bodies need for growth and development.
Vitamin A is found naturally in the foods we eat, and it can also be consumed in supplement form. There are two types of vitamin A: preformed vitamin A, which is found in animal products; and provitamin A, which is found in plant-based foods containing beta-carotene.
We mainly store vitamin A in our livers in the form of retinyl esters – and because it’s fat soluble, we can store it in our bodies for later use.
Why is vitamin A important for our health?
Vitamin A is essential for our health and has several important functions. It can improve our vision, boost our immune system, and help keep the skin and lining of other body parts, like the nose, healthy. It also helps organs like the heart, lungs, and kidneys function properly.
Let’s take a closer look at some of vitamin A’s main benefits:
1. Vitamin A helps preserve your eyesight
One of the first symptoms of vitamin A deficiency is nyctalopia – which is night blindness. People suffering from night blindness can see normally in the daylight, but struggle to see when it’s dark. The reason for this is that vitamin A is a main component of rhodopsin: a pigment found in the retina of our eyes that’s extremely light-sensitive and helps us to see at night.
As well as helping to prevent night blindness, eating enough beta-carotene (the precursor of vitamin A that’s found in plants) may help slow age-related macular degeneration (AMD), which is the leading cause of blindness in the West. One study found that giving a beta-carotene supplement to people over the age of 50 with eyesight degeneration reduced their chances of developing advanced macular degeneration by 25%.
We’ll take a look at the best sources of beta-carotene later in this article.
2. Vitamin A might reduce the risk of certain cancers
Cancer develops in our bodies when abnormal cells start to grow or break apart in an uncontrolled way. Because vitamin A plays a key role in our cell’s growth and development, it’s thought to be linked to cancer prevention – although more research is needed before we can draw definitive conclusions.
In observational studies, eating more vitamin A in the form of beta-carotene was associated with a lower risk of cervical cancer, lung cancer, and bladder cancer as well as Hodgkin’s lymphoma. However, although eating more plant-based sources of vitamin A is associated with a reduced risk of cancer, animal products containing vitamin A aren’t linked in the same way, and neither are vitamin A supplements.
Currently, the link between vitamin A levels in your body and the chance of developing cancer isn’t fully understood, but there is evidence that getting enough vitamin A from whole plant foods may reduce your risk of certain cancers.
3. Vitamin A helps support bone health
Many of us might be aware that the most important nutrients for maintaining bone health as we get older are calcium and vitamin D – but vitamin A is also crucial for bone health.
Studies show that people with lower levels of vitamin A have an increased risk of bone fractures than people with healthy levels of vitamin A. Plus, other studies show that people who consumed the highest amounts of vitamin A from their diet had a 6% decreased risk of fractures overall.
However, while there’s evidence to suggest that getting enough vitamin A may help protect your bones, the link between vitamin A and bone health isn’t yet fully understood, and more research is needed.
4. Vitamin A helps support your immune System
Vitamin A plays a crucial role in helping to maintain our body’s natural defenses. Vitamin A is needed to create cells including B- and T-cells, which play essential roles in immune responses that protect against disease. Being deficient in vitamin A can lead to higher levels of pro-inflammatory molecules that weaken both our immune system response and our immune function.
Vitamin A also helps with the production and function of white blood cells, which capture and remove bacteria and other harmful pathogens from our bloodstream. Being deficient in vitamin A can not only increase our chances of contracting infections, but also delay recovery. Studies show that in countries where diseases like measles and malaria are prevalent, correcting vitamin A deficiency decreases the risk of dying.
5. Vitamin A can improve skin conditions
There’s also evidence to suggest that vitamin A can improve chronic skin conditions, like acne. People suffering from acne develop painful spots and blackheads, usually on the face, back and chest. While acne is physically harmless, it can lead to low self-esteem, anxiety, and depression.
While the precise role that vitamin A plays in developing and treating acne isn’t yet clear, there’s evidence suggesting that being deficient in vitamin A may increase your chances of developing acne. This is because it causes an overproduction of the keratin in the hair follicles, leading to blockages that increase the risk of acne.
Isotretinoin is one example of a vitamin-A-based medication that’s been found to be effective in treating acne. However, this is only available with a prescription and not over-the-counter.
Am I getting enough vitamin A?
So now we know why vitamin A is so important, how can we be sure we’re getting enough? According to the NHS, men need 700 mcg of vitamin A each day, and women need 600 mcg. You should be able to get all the vitamin A you need from your diet – and because our bodies can store vitamin A for later use, this means we don’t need to consume it every day.
There are two dietary sources of vitamin A: preformed vitamin A and provitamin A carotenoids. Preformed vitamin A is found in animal products, and some of the best sources include:
- Organ meats – like liver
- Egg yolks
- Oily fish – like tuna, trout, herring, salmon, and mackerel
- Cod liver oil
- Milk and cheese
Plant-based sources of vitamin A contain antioxidant forms of it called carotenoids, which our bodies then convert into retinol. The best sources of foods high in provitamin A carotenoids include:
- Dark green leafy veg – like kale, spinach, Swiss chard, and collard greens
- Broccoli
- Red and orange peppers
- Sweet potatoes
- Pumpkin
- Carrots
- Cabbage
- Butternut squash
- Fruits including cantaloupe melon, apricot, orange, and mango
Vitamin A toxicity
Just as being deficient in vitamin A can harm your health, getting too much of it can also be dangerous. The recommended daily allowance for both men and women can be easily reached by following a healthy diet containing lots of whole foods – and being deficient in vitamin A is rare in the developed world.
It’s important to note that because vitamin A is fat soluble and our bodies are able to store it, excess consumption can lead to toxicity. For example, hypervitaminosis A is caused when we consume too much preformed vitamin A – and symptoms can include nausea, vision problems, and changes in the skin.
Research also suggests that consuming more than 1,500 mcg of vitamin A a day can impact your bones, making them more prone to fracture as you age. This risk can be greater for women who are already at a higher risk of suffering from osteoporosis due to menopause.
The NHS says that if you eat liver or liver pâté (a very high preformed source of vitamin A) once a week, you may be getting too much vitamin A – particularly if you take a multivitamin, as this usually contains vitamin A. If you take any supplements containing vitamin A, it’s important to make sure that your overall consumption from food and supplements isn’t over 1,500 mcg.
It’s worth noting that preformed vitamin A is found in animal food and supplements, and that eating lots of provitamin A in plant forms doesn’t carry the same risks. This is because our bodies regulate how much of provitamin A we convert into the active form of vitamin A.
People with the highest risk of being vitamin A deficient include preterm infants, babies and children, pregnant and lactating people in developing countries, and people with cystic fibrosis. If you’re unsure whether you’re getting enough vitamin A, it’s important to speak with your GP before taking any supplements.
Final thoughts…
Vitamin A is an essential fat-soluble nutrient that plays a key role within the body. It’s vital for proper immune function and eye health, and is also linked to reducing the risk of cancer, boosting bone health, and improving chronic skin conditions like acne.
While being deficient in vitamin A is harmful, having too much can be equally dangerous, so it’s important not to consume too much. Eating a fresh, healthy diet is the best way to ensure you’re getting enough of this vital nutrient.
Do you feel like you have healthy levels of vitamin A – or are you worried you might be consuming too much? Do you have any additional tips for staying healthy? We’d love to hear from you in the comments below.