Vitamin A
Moist eyes, smooth skin, strong immunity, healthy vision and sleep, and many other amazing benefits.
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Today we are talking about vitamin A!
Do your eyes ever feel dry?
Or do you have trouble seeing at night?
Maybe your eyes are fine, but you get colds a lot. ð€
Or your sleep is really messed up... like your body just doesn't know when it's time to sleep or time to wake up. Your mind racing at night, and your eyelids drooping in the day.
Or maybe your skin gets crusty underneath your hair, or you get little bumps that look like goosebumps or acne but they never go away.
How Vitamin A Makes Our Eyes Moist, Our Skin Smooth, and Our Immune System Strong
All of these problems can be caused by too little vitamin A. Why? First of all, vitamin A lubricates your eyes. But vitamin A isn't "wet." It doesn't moisten everything in sight. Instead, it's what your tissues use to develop properly. It's how they "know" what they're supposed to do. It's a tool our cells use to know they are creating the right things and putting them all in the right places.
They use it like we use mirrors. The mirror doesn't make your lips red, but try putting lipstick on without one and you might look a little silly. ð¬
Your eyes use vitamin A to become moist, but your skin uses it to become soft and smooth.
Then inside your throat, on the way down to your lungs, there are little "hairs" that catch all the junk and little microbes you breath in and help you cough it all out. Vitamin A helps make those hairs! As if that weren't enough, vitamin A helps your immune system become strong, making antibodies and virus-busting proteins. These help fend off any nasty critters that made it past your moist eyes, your smooth skin, and your killer cough response.
But... oh man... let's go back to the eye for a minute.
No, I mean, this is some crazy stuff going on in the eye. ð
How Vitamin A Promotes Healthy Vision and Healthy Sleep
Vitamin A is what your eyes use to sense light. When the light enters your eye, it hits a molecule of vitamin A, and that triggers a reaction that sends an impulse to your brain. Your brain takes thousands of these impulses in any given instant and integrates them together to make your sense of vision.
If you are deficient in vitamin A, you don't go blind... at least not at first.
Why?
Because you have two different types of cells in your eyes: rods help you see shadows in the dark, cones help you see colors in the day. Vitamin A is equally important to both of them, but when you're running low, your body starts setting priorities. Back before artificial lighting, there wasn't much to do at night. Chat by the fire, then hit the sack. Being able to see at night wasn't that big of a deal. It was time to sleep. The day was time for hunting. Gathering. Making tools. So we sacrifice our night vision when we become deficient in vitamin A. This helps make sure we have enough vitamin A to see during the day.
And you know what ELSE light does in our eyes? Besides help us SEE??? ð
It tells our brains that it's day time. Have you noticed the "blue-blocking" bandwagon so many people are hopping onto lately? Like "Nightshift" on iPhone, "Night Mode" on Android, Flux on the computer, or those funky amber-colored glasses the geeky guys (like me!) wear? These block the blue light from our light bulbs and digital screens. That blue light tells our brains that it's day time. Just like vitamin A transmits light signals to the brain to help us see, it's vitamin A transmitting these signals that it's daytime. So if you feel awake at night or tired during the day, one possibility is that vitamin A is missing... The light hits your eyes, but the vitamin A isn't there to transmit the signal to your brain.
Other Amazing Things Vitamin A Does
Vitamin A does some other amazing things:
It protects against kidney stones.
It protects against "autoimmune" diseases. These are diseases where the body attacks itself, like type 1 diabetes.
It protects against asthma and allergies.
And it protects against food intolerances like celiac disease (a condition where gluten, a protein in wheat and several other grains, wreaks havoc on the intestines).
It helps make hormones like testosterone and estrogen.
In fact, without vitamin A, boys won't go through puberty!
Vitamin A in Foods
So how do we get enough vitamin A?
There are two forms of vitamin A: the form in plant foods, and the one in animal foods. The plant form is actually a collection of compounds. One of them is beta-carotene. The others are similar to it and called "carotenoids."
These are named after carrots. ð°
Oops that's a rabbit.
Let's try this again.
These are named after carrots. ð¥
The animal form of vitamin A is called retinol. This is named after the retina, the part of the eye where most of the vitamin A is found.
We don't need the plant form (carotenoids) in our bodies. We do need the animal form (retinol). But! We can convert the plant form into the animal form. In other words, we can convert carotenoids to retinol. There's actually over SIX HUNDRED (!!!) different carotenoids, and not all of them act as vitamin A. For example, lutein and zeaxanthin, found in spinach and eggs, might help protect us from going blind when we get old. This is because they protect against a disease called age-related macular degeneration. But they don't act as vitamin A. Some people think the lycopene in tomatoes protects against prostate cancer or cardiovascular disease (it's controversial!). But lycopene doesn't act as vitamin A. Only about 10% of carotenoids act as vitamin A, and these are called "provitamin A carotenoids." The PRO in "provitamin A" refers to the fact that they can be converted into the active form of vitamin A, retinol.
Carotenoids are colorful! They can be red, orange, or yellow. So, you know your plant foods have vitamin A potential if they are red, orange, or yellow. But get this... GREEN foods have potential vitamin A too! Why? Because the green is chlorophyll, which plants use to obtain energy from the sun. The carotenoids act as the chlorophyll's assistants, so you can always be sure that when you see green, those other colors are lurking beneath the surface.
For example, have you noticed the colors the leaves turn in the fall? Those shades of red, orange, and yellow are carotenoids. As the chlorophyll degrades, it reveals the other colors that had been present all along. So, to get vitamin A from plants, we eat red, orange, yellow, and green vegetables.
When we eat vitamin A, guess where we hold on to it? Our livers! And just like we store vitamin A in our livers, so do fish, cows, chickens, and all the other animals. So, the best source of animal-form vitamin A is liver. Cod liver oil can be used as a supplement because it's simply the oil squeezed out of the livers of fish. Most other animal foods are not a good source of vitamin A, with two exceptions: eggs and milk. Why? These are the two foods meant to nourish young animals, who need lots of vitamin A to grow correctly. In fact, an egg has a rather marvelous task to fulfill: it has to fit enough nourishment to last the chick 21 days until it hatches and eats its first worm. It has to pack a LOT of nutrition. And milk is meant to nourish the growing calf. Both of these have vitamin A... but nowhere near as much as liver.
Now, you might think we could get vitamin A from plant foods and animal foods equally well. But here's the thing: We need the animal form, retinol. We don't need the plant form, carotenoids. So when we get vitamin A from plant foods, everything comes down to how good we are at converting the carotenoids to retinol.
Getting Vitamin A From Plant Foods Is Hard!
And there are SO MANY things that get in the way:
âfiber
âparasites
âtoxic metals like mercury and lead
âdamaging molecules produced during metabolic problems like diabetes
âiron deficiency
âzinc deficiency
âprotein deficiency
âhypothyroidism
The worst of these is GENETICS. About half the population has their ability to get vitamin A from plant foods cut at least in half. And half of those people -- a quarter of the total population -- has it cut by 75%. Layer on any of the â's listed above and the picture just gets more and more bleak.
So colorful vegetables MIGHT be a good source of vitamin A for you, but ARE they? ð€·ââïž
Things That Boost Our Vitamin A
Ok, enough of the stuff that makes getting vitamin A *harder.*
Here are things that help!
Vitamin A mixes with fats and oils better than it mixes in water. That means eating it with fat helps us absorb it.
The best fats to use are animal fats and traditional oils like palm oil and olive oil. If you want to look up a specific oil, look up the type of fat it has and use oils that are low in polyunsaturated fat.
Cooking or pureeing vegetables helps us get more vitamin A from them.
Vitamin E helps us get more vitamin A from plant foods.
Here's what I recommend as the best way to get vitamin A:
Eat 4 ounces of liver once a week, or eat a half ounce every day.
If you tolerate eggs, eat up to three whole eggs a day.
If you tolerate milk, consume up to three servings of full-fat dairy per day.
Eat 3 or 4 cups of red, orange, yellow, and green vegetables a day.
Don't go out of your way to eat a high-fat diet, but don't avoid fat either.
To super-charge your vitamin A, use grass-fed butter and red palm oil for your added fats.
Red palm oil is a great plant source of vitamin A. It happens to be super-rich in carotenoids *and* vitamin E *and* all the right fats. And it's even better than pureed vegetables. Because it is an oil, the carotenoids are already perfectly dissolved and you don't need to do much digesting to extract them.
Vegans, Low-Fat Dieters, and Children
Now, some people will need to change things up!
First, LOW-FAT. If you avoid adding fats and oils to your food, emphasize lean cuts of protein, and avoid egg yolks or full-fat milk products, you qualify as "low-fat."
ð Triple your animal-form vitamin A by eating 12 ounces of liver a week.
Second, VEGAN. If you don't eat *any* animal products, you're a vegan.
ð Use red palm oil liberally as often as you can stand it.
ð Supplement if you have symptoms of deficiency.
And then there's CHILDREN. The best thing to do for children is cut these down based on the amount of food they eat. For example, if they eat half as much as you, feed them half as many of these foods. If they eat twice as much as you, feed them twice as many of these foods. If you want to put numbers on it, cut these serving sizes in half, then multiply that by every 1000 Calories in your child's diet. Do the same thing for the supplement doses I'll discuss below.
Vitamin A Supplements
If you can't meet the food recommendations (or just refuse to eat liver and palm oil!), you should consider supplementing. When supplementing, we need to start counting. Vitamin A is measured in "international units" or IU.
ð¥Cod liver oil providing 3000 IU per day from a brand that doesn't use synthetic vitamins is the most natural source.
ð You can also just take a vitamin A supplement. Take 3,000 IU a day, or 10,000 IU twice a week. If you take more, you should work with a knowledgeable health care practitioner and make sure all your other nutrients are adequate to avoid imbalances.
Vitamin A Toxicity
Vitamin A has a dark side. Yes, it can be toxic! ð¬
â£ïž It can hurt your bones, especially when you don't have enough vitamin D.
â£ïž In the first 8 weeks of pregnancy, too much might cause birth defects.
Taking way too much for way too long a time can cause these problems:
â£ïž Fatigue
â£ïž Hair loss
â£ïž Upset stomach, nausea, and vomiting
â£ïž Dry, peeling, or itchy skin
â£ïž Cracked lips
â£ïž Headache
The best way to avoid these problems is to avoid taking too much, and to keep the rest of your diet balanced. Here are some rules to follow to make sure you don't experience any problems from too much vitamin A:
â Keep retinol to no more than 3,000 IU per day or 10,000 IU twice a week unless you have deficiency symptoms that only go away at higher doses.
â If you supplement with more, include supplements of vitamins D, E, and K. I'll give you dosing recommendations when we get to those lessons!
â Work with a knowledgeable health care practitioner if using high doses, especially if you have any symptoms of toxicity.
Wrapping Up
Allright, that's it for vitamin A!
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I hope you enjoyed your first day of class! Tomorrow we move on to thiamin, or vitamin B1!
Class dismissed,
Chris
As always, a clear and concise delivery regarding vitamin A. Thank you, Chris!
I'm a bit confused, how can the lower limit for avoiding deficiency be at the same point as the upper limit for avoiding toxicity (ie 3000 iu)?