How to Know If You Have Vitamin A Toxicity | Chris Masterjohn Lite #125

November 19, 2019 0 By William Morgan

Vitamin A toxicity. Is it a problem? Hi. I’m Dr. Chris Masterjohn of And this is Chris Masterjohn Lite, where the name of the game is “Details? Shmeetails. Just tell me what works!” And today we’re going to talk about vitamin A toxicity. Vitamin A is a nutrient, and it is not a toxin. However, like with many other things, too much of a good thing can become a bad thing. And vitamin A when it accumulates in the body can cross a certain threshold that contributes to toxicity. So, how do you know if you have toxicity? Well, the most common symptoms are nausea, vomiting, and headache. As vitamin A toxicity gets worse, it can cause anorexia, blurred vision, scaling skin, hair loss in the form of an autoimmune condition known as alopecia, organ damage, and in very rare cases death. So, it’s a serious concern, but in the vast majority of cases, we’re looking at things like nausea, vomiting, and headache as the big warning signs. Now, nausea, vomiting, and headache can have many causes, so we want to consider two other important pieces of data. One is how much vitamin A have you been exposed to, and the other is some lab tests. If we limit our discussion of vitamin A to vitamin A found in food and to vitamin A supplements that are either naturally occurring in the case of liver or cod liver oil supplements, or are normal fat-soluble, such as retinol palmitate. And we’re not talking about retinol acetate, and we’re not talking about any forms that have been prepared specifically to be more water-soluble for people who have trouble absorbing vitamin A through the normal processes. So, if we limit our discussion to normal fat-soluble vitamin A, for a 150-pound adult, we would require more than 10,000 IU of vitamin A taken over months to years consistently every day as an absolute minimum for what’s been reported to cause toxicity. The average case is over 150,000 IU taken every day for months or years to lead to toxicity. Now, this is in people who are not supplementing with other nutrients. So, vitamin D for example is very protective against vitamin A toxicity. And if you look at the case reports of vitamin A toxicity, the doses that cause toxicity when people are also supplementing with vitamin D are far higher. In these cases vitamin A toxicity requires an average dose of more than 300,000 IU per day taken every day for months or years. On the other hand, whereas vitamin D is protective, using water-soluble preparations of vitamin A makes it more dangerous. There you can see toxicity with ten times lower doses, and you can see toxicity in a shorter period of time ranging from weeks to months of taking it every day instead of from months to years. The other important piece of data is lab tests. So, the lab tests that are likely to be elevated in vitamin A toxicity are as follows starting with the ones that are most common. Most commonly the serum vitamin A is going to be elevated above the top of the reference range. The next most likely test to be elevated above the top of the reference range is gamma-glutamyl transferase. The next most likely is triglycerides. The next most likely after that is alkaline phosphatase. The next most likely after that is the prothrombin time. After that, cholesterol. After that, AST, one of the liver enzymes, so called. After that, bilirubin. And the test that is commonly found to be elevated but is the most least likely out of all of these to be elevated is serum calcium. So, together when you’re looking at the signs and symptoms, and you’re looking at the exposure to vitamin A, and you’re looking at the blood tests, you can assess the probability that you have been exposed to toxic amounts of vitamin A over time. You don’t need every single piece of data to add up nice and neatly, but you need things from each category to make it make sense to consider vitamin A as the thing that’s probably at the root of whatever problem you’re trying to fix. Now, there are some special additional concerns about excess vitamin A. Excess vitamin A even when it’s not at toxic levels can worsen osteopenia and osteoporosis when someone is deficient in the other nutrients needed to protect against those diseases, particularly calcium and vitamin D. So, this is not a matter of vitamin A being toxic. It’s a matter of vitamin A being out of balance with the other nutrients. If you’re running deficient in calcium and deficient in vitamin D, and yet you’re running on the high end of normal vitamin A, that imbalance is going to be a problem, but what you really want to do is pull the other nutrients up to be in balance with it. There are concerns about too much of vitamin A going into the first eight weeks of pregnancy, and I have some of my own concerns about vitamin A and fatty liver. So, I’m going to make special episodes about those coming up next because I believe that those issues deserve special episodes. Finally, if you want all this information about signs and symptoms, about exposure amounts, and about different tests to run for vitamin A toxicity, all in one place integrated into a comprehensive guide for managing nutritional status for vitamin A and all the nutrients, then all this stuff can be found in Testing Nutritional Status: The Ultimate Cheat Sheet. If you don’t have your copy yet, you can get your copy at And you can use the code: LITE5 that’s L I T E and the number 5 LITE5 to get five dollars off. This episode is brought to you by Ancestral Supplements living collagen. Our Native American ancestors believed that eating the organs from a healthy animal would support the health of the corresponding organ of the individual. Ancestral Supplements has a nose-to-tail product line of grass-fed liver, organs, living collagen, bone marrow, and more. All in the convenience of a capsule. For more information or to buy any of their products, go to This episode is brought to you by Ample. Ample is a meal in a bottle that takes a total of two minutes to prepare, consume, and clean up. It provides a balance of fat, protein, and carbs plus all the vitamins and minerals you need in a single meal. All from a blend of natural ingredients. iI’s available in original, vegan, and keto versions portioned as either 400 or 600 calories per meal. I’m an advisor to Ample, and I use it to save time when I’m working on major projects on a tight schedule. It keeps my brain going while I power through the day, never letting food prep get in the way of my productivity. Head to and enter the promo code: CHRIS15 at checkout for a 15% discount off your first order. For ad-free versions of these episodes with transcripts that you can read and getting early access to the episodes often weeks or maybe even months ahead of time, you can sign up for the CMJ Masterpass at And use the code: LITE10 to get 10% lifetime discount. The audio of this episode was enhanced and post-processed by Bob Davodian of Taurean Mixing. You can find more of his work at All right. I hope you found this useful. Signing off, this is Chris Masterjohn of This has been Chris Masterjohn Lite. And I will see you in the next episode.