Vitamin A is an important nutrient the body requires for optimal function and is involved in ensuring your eyes are moist, your skin is smooth and your immune system is robust. Your tissues use vitamin A for proper development and vitamin A helps your tissues to ‘know’ what they need to do. Different tissues use vitamin A for different functions.
Role Of Vitamin A In The Body
Moist Eyes, Smooth Skin & Robust Immune System
Dry eyes, rough skin and a weak immune system (shown by susceptibility to colds) are all problems which could be caused by a lack of vitamin A. Yet despite vitamin A helping to lubricate the eyes, it isn’t a wet molecule. What I mean by this is that it doesn’t have the same function in all tissues. It doesn’t lubricate all tissues.
Your skin uses vitamin A to become soft and smooth whilst your immune system uses vitamin A to produce antibodies and antiviral proteins, helping to fight off any potentially harmful microorganisms that may get past your other mechanisms of defence such as mucus, skin, stomach acid and chesty cough.
How Vitamin A Helps Vision And Aids Sleep
Vitamin A is very important when it comes to eye health, playing a role in sensing light. When light enters your eye, it hits a molecule of vitamin A, triggering a reaction that sends an electrical impulse to your brain. Many of these impulses are generated from light hitting your eye and your brain integrates them all together to create an image. This is what you see. Personally, I think this is incredible.
The logical thing to assume would be, surely if you don’t consume enough vitamin A you would go blind. However, this isn’t the case – at least not initially and that’s because there are two main light-sensing cells within your eyes.
You have cones and rods. Cones allow you to see colours whilst rods allow you to see black and white. Vitamin A is used by both of these cells, but when you’re low in vitamin A your body will reduce the vitamin A available for your eyes to use. When artificial lighting didn’t exist, not being able to see clearly at night wasn’t a problem. It meant we’d sleep. Then during the day, it’d be time to hunt, forage and participate in social gatherings. When you become deficient in vitamin A your night vision diminishes so that you have enough vitamin A during the day when it’s more important.
The Rise Of Blue Light Blockers
Light is one of the world’s wonders that our body uses to regulate parts of our circadian rhythm. When that burst of morning sunrise breaks through the curtains, it tells us it’s day time and we need to get up, more and be proactive.
Blue light tells our brains that it’s day time – it increases attention and alertness. More and more people are realising that blue light is interfering with sleep quality so those who stay up late on electronic devices at night are beginning to implement blue light blockers such as f.lux, ‘nightshift’ on iPhone and ‘nightmode’ on Android.
Other Functions Of Vitamin A
As well as playing a role in lubricating the eyes, softening skin and strengthening your immune system, vitamin A also has a few other amazing functions:
- Provides protection against kidney stones.
- Provides protection against autoimmune diseases such as lupus or type I diabetes where the body attacks itself.
- Provides protection against asthma and allergies.
- It helps synthesise hormones such as testosterone and oestrogen.
Sources Of Vitamin A
There are two main sources of vitamin A we can consume. One is from animal foods and the other is from plants. The vitamin A sourced from plants are called carotenoids (heard of beta-carotene?). Carotenoids are actually a collection of compounds and they’re named after carrots. It kind of makes sense to me since I was told when I was young that I should eat carrots to see better in the dark, but let’s dive in a bit deeper into the differences between the animal form and plant form of vitamin A.
Carotenoids And Vitamin A
The human body requires the animal form of vitamin A (known as retinol) in the body, carotenoids aren’t actually required but the body can convert carotenoids into vitamin A. The only possible problem is that not all carotenoids can be converted into vitamin A. About 10% of all carotenoids are converted into vitamin A, and there are over 600 different carotenoids and they each play different roles within the body – not all of them act as vitamin A. Here are a few examples:
- Lycopene (found in tomatoes) protects against prostate cancer, lung cancer and cardiovascular disease as well as decreasing bone resorption (the breakdown of bones).
- Alpha-carotene has been shown to improve longevity and has been inversely associated with cancer deaths, cardiovascular disease and other illness deaths.
- Beta-carotene helps protect against sunburn and could help reduce the risk of metabolic syndrome.
Carotenoids are found present in lots of colourful vegetables; yellow, red or orange. However, that doesn’t mean carotenoids aren’t present in green vegetables. In fact, as the chlorophyll which reflects green light, giving off that green colour degrades, it reveals the other colours present in the vegetable. That’s why tomatoes start off green and slowly turn red.
Retinol And Vitamin A
Vitamin A can be obtained in the ‘human form’ without the need for conversion from carotenoids by consuming it from animal sources. Vitamin A is stored in the liver of animals including humans which makes eating liver the best way to increase your consumption of vitamin A. Other than liver, the best sources of retinol are eggs and milk. This is because these foods are actually meant to nourish young animals meaning that they contain the nutrients the young animals need to thrive, so naturally, they both contain vitamin A. However, neither of these come close to the vitamin A content of liver.
Why Plant Food Aren’t Ideal For Vitamin A
Whilst obtaining vitamin A from animals or plants both seem like viable options, there are a few reasons why plant foods aren’t ideal for vitamin A. This is because:
- Fibre gets in the way.
- Conversion of carotenoids into retinol isn’t efficient.
Genetics is probably the worst problem here since approximately 50% of the population has their ability to convert carotenoids into retinol reduced by 50%.
Now don’t get me wrong, vegetables are great for providing other forms of protection against disease and strengthening the immune system, but I wouldn’t advise consuming vegetables or plants to obtain vitamin A.
Boosting Vitamin A Intake
There are a few tricks you can use to boost vitamin A intake and enhance absorption:
- Consume your vitamin A with fats (vitamin A is a fat-soluble vitamin); the best fats are animals fats, palm oil and olive oil.
- Cooking or pureeing vegetables to help extract more vitamin A from them.
- Having vitamin E rich foods with vitamin A rich foods to enhance absorption.
To ensure you consume enough vitamin A, I suggest doing the following;
- Eat a minimum of 200g liver weekly, up to 400g (spread it out however you want).
- Consume up to four eggs daily if you’re not allergic to eggs.
- If you don’t have lactose or casein sensitivities, consume some full-fat dairy (up to three servings daily).
- Eat three cups of colourful vegetables daily.
- Don’t avoid fat in foods, but don’t try and add lots to your food.
Alternatively, you could also supplement vitamin A by consuming cod liver oil from a brand that doesn’t use synthetic vitamins and sources their cod liver oil naturally. Over the course of a week, you’d want to take around 3,000 IU’s daily.
Vitamin A Toxicity
Whilst vitamin A has many profound benefits, if you overdose on vitamin A it can also be toxic. Too much vitamin A could potentially cause:
- Pain in your bones
- Birth defects
- Reduced appetite
- Cracked lips
- Dry skin
- Hair loss
Don’t be too afraid of consuming vitamin A, just don’t consume lots and lots thinking more is better. If you stick to 200g to 300g of liver weekly then you should be good. Pay attention to how your body reacts and decide how to adjust your diet and what you eat.
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