- Accutane / isotretinoin. This is an oral acne drug that is nothing more than ultra-high dose Vitamin A,
I may add that is a synthetic ultra-high dose form of vitamin A:
The recommended dosage range for Accutane is 0.5 to 1.0 mg/kg/day given in two divided doses with food for 15 to 20 weeks.
So for a average 70kg human at the smallest dose that's at least 70 mg of Accutane. If it had any resemblance to natural Retinol, it would amount to 233.000 IUs vitamin A per day! That would be an insane daily dose for up to 5 month, even if would be only natural vitamin A.
https://en.wikipedia.org/wiki/Vitamin_A#Side_effects
In general, acute toxicity occurs at doses of 25,000IU/kg of body weight, with chronic toxicity occurring at 4,000IU/kg of body weight daily for 6–15 months.[38] However, liver toxicities can occur at levels as low as 15,000IU (4500micrograms) per day to 1.4 million IU per day, with an average daily toxic dose of 120,000IU, particularly with excessive consumption of alcohol.[citation needed] In people with renal failure, 4000IU can cause substantial damage. Signs of toxicity may occur with long-term consumption of vitamin A at doses of 25,000–33,000IU per day.[1]
Personally I've following Linus Pauling therapy recommendation, except for vitamin A where he recommends 25.000 IU daily. Took my time and gradually increased while periodically testing serum retinol and retinol binding protein. Took my about 8 year till I reached his recommended dose, and to my surprise from there onward never experienced any of my before infrequent psoriasis outbreaks. Further, my serum level hasn't risen much more than still below the mean of normal.
So I would clearly distinct between these insane doses of a synthetic analog from vitamin A, an essential beneficial nutrient. Which this day probably many are deficient in, since an other study found that up to 50% of females can't convert to active vitamin A from beta-cartene.
How Much is Too Much? : Appendix B: Vitamin and Mineral Deficiencies in the U.S.
Nutrient from food alone, ranked by the occurrence of dietary inadequacy among adults | Percentage of dietary intakes below the estimated average requirement for a specific population* | Naturally occurring sources of nutrient**
2-to-8-year-old children | 14-to-18-year-old girls | Adults 19 and older
Vitamin D | 81% | 98% | 95% | Fatty fish, mushrooms [vitamin D is naturally formed in the body when skin is exposed to sunlight; vitamin D is added to fortified milk]
Vitamin E | 65% | 99% | 94% | Nuts, seeds, vegetable oils, green leafy vegetables
Magnesium | 2% | 90% | 61% | Whole grains, wheat bran and wheat germ, green leafy vegetables, legumes, nuts, seeds
Vitamin A | 6% | 57% | 51% | Preformed vitamin A: liver, fatty fish, milk, eggs; provitamin A carotenoids: carrots, pumpkins, tomatoes, leafy green vegetables
Calcium | 23% | 81% | 49% | Milk, yogurt, cheese, kale, broccoli
Vitamin C | 2% | 45% | 43% | All fruits and vegetables, particularly citrus fruits and tomatoes
Vitamin B6 | 0.1% | 18% | 15% | Many foods; highest levels in fish, beef, poultry, potatoes and other starchy vegetables, and fruit other than citrus
Folate | 0.2% | 19% | 13% | Many foods; highest levels in spinach, liver, asparagus, Brussels sprouts [mandatory, standardized addition to enriched flour and flour products]
Zinc | 0.2% | 24% | 12% | Red meat, poultry, beans, nuts, some seafood, whole grains
Iron | 0.7% | 12% | 8% | Highest amounts in meat and seafood; lower levels in nuts and beans [mandatory, standardized addition to enriched flour and flour products]
Thiamin | 0.1% | 10% | 7% | Whole grain products [mandatory, standardized addition to enriched flour and flour products]
Copper | 0% | 16% | 5% | Shellfish, whole grains, beans, nuts, potatoes, organ meats (kidneys, liver)
Vitamin B12 | 0% | 7% | 4% | Animal products: fish, meat, poultry, eggs, milk
Riboflavin | 0% | 5% | 2% | Milk and dairy products, eggs, meat, green leafy vegetables, legumes [mandatory, standardized addition to enriched flour and flour products]
Niacin | 0.1% | 4% | 2% | Meat, fish, seeds and nuts, whole grains [mandatory, standardized addition to enriched flour and flour products]
Selenium | 0% | 2% | 1% | Found in different plant and animal foods; highest levels in seafood and organ meats (kidneys, liver)