I needed to do the math on this.
The RDA is 900mcg, aka 900ug or 0.9mg.
1IU = 0.3ug retinol, roughly.
Personal Experience
I had a period of dry eyes while detoxing from isotretinoin that lasted for a few months. However, the beginnings of dry eyes return when I eat food that contains Vitamin A… and that’s pretty much everything in America. Eggs, pork, products made with skim milk (ice cream, cheese, yogurt), and so on.
It’s a real feeling. I feel a tingling/dryness/pain on my face where I am more oily and my eye’s glands. This is because fat-soluble toxins are detoxed through the sebaceous glands.
How much Vitamin A might you consume in a day?
Let’s say you have a croissant from Costco (+72ug), some 500ml of skim milk (1020IU = 306ug), and a yogurt (245g cup) for breakfast (estimated 150ug if derived from skim milk).
Let’s go to Starbucks for lunch and have a two egg sandwich (+126ug). The chickens are fed Vitamin A in their grain feed and it goes into the eggs. If you eat any skim milk ice cream you’ll get another dosage of Vitamin A. If you eat something like fatty pork belly, you’ll also get some more Vitamin A.
So we see it’s not hard to eat around 0.6mg of retinol per day, increased if someone takes multivitamins or cod liver oil. If you eat like this for an entire year, you’ll have eaten 219mg of it. From personal experience, 1g of fat, carbs, or protein is nothing. A few hundred mg of something insignificant isn’t that weird. But even 10-30mg of retinoids are a lot.
How might you try this out?
Stop eating food that contains added Vitamin A. Most animal fat (including beef), eggs, skim milk. White rice and lean beef are good choices. Stay away from beta-carotene sources like sweet potatoes anyways.
Is Vitamin A the cause of eczema?
This blog set me on the course of thinking and learning about Vitamin A. In Winter 2022, I had serious intestinal pain, SIBO, autoimmune issues, and so on. But what was also interesting was how I got eczema on my arm after one particularly strong attack. Another instance had an age spot that appeared on my hand but subsequently fell off.
One guy I met who takes a multivitamin every day has the skin above his brow bleached. Retinoids excrete through sebaceous glands and bleach skin. There was another guy I met who seemed particularly unhealthy. He had dry eyes, thin hair, and eczema around his eyes. Doctors prescribed steriod creams.