Monday, January 23, 2012

My Interview With Carl Lanore on Superhuman Radio: The Real Story About Vitamin A

by Chris Masterjohn

Earlier this afternoon, Carl Lanore interviewed me about vitamin A for his show, Superhuman Radio.

The easiest way to access this show is to right-click on the following link and save it to your computer, though you can also access it in ITunes or listen to it on the front page of Carl's web site.  Here's the show:

My interview is in the second half of the show, beginning about an hour in.  To make it easier to navigate through the show and find what you want, I created this table of contents:

0:58:55 -- Carl introduces me.
1:00:20 -- Why is there so much conflicting information out there about vitamin A?
1:02:50 -- Vitamins A and D in stem cell differentiation, relation to tooth decay and

1:05:12 -- Is it reckless to take vitamins A and D without vitamin K?
1:09:20 -- Dark skin can increase the requirement for sunshine or oral vitamin D.

1:11:30 -- Commercial Break

1:14:50 -- Can we get enough vitamin A from beta-carotene?
1:17:44 -- Vitamins A and D are not hormones, they're the "raw materials of

1:18:40 -- What are the right doses and ratios of vitamins A and D?
1:22:28 -- It's not so obvious that the toxic component of polar bear liver is vitamin A.
1:24:45 -- Vitamin A toxicity, relevant blood tests, subclinical toxicity of vitamins A and D.

1:30:30 -- Commercial break

1:34:10 -- Dietary fat and the absorption of fat-soluble vitamins.
1:36:18 -- Did cod liver oil contribute to the historical decline in infectious diseases from
                1850-1950?  Has the replacement of cod liver oil with antibiotics as the leading
                pharmaceutical strategy to combat infectious disease led to an increase in
                autoimmune disorders?

1:45:40 -- Commercial Break

1:50:13 -- How to keep up with my writings.
1:51:30 -- Should Carl be taking cod liver oil instead of supplementing with vitamins A
                and D?

1:53:20 -- Why my choice of cod liver oil offends Carl's taste buds.   Thankfully, not
                everyone needs cod liver oil.

1:57:00 -- Upcoming stuff, and goodbye!
1:57:55 -- Carl wraps it up.

Read more about the author, Chris Masterjohn, PhD, here.


  1. Hey Chris, great interview.

    I'm wondering... why do studies, like that one from Tufts, use retinoic acid instead of retinol? How much can the results tell us about the kind of vitamin A people actually eat?

  2. I've also wondered if some people might have poor retinoic acid activity for reasons other than poor vit A intake. Hyperinsulinemia is one idea I've heard of.

  3. Thanks so much for the TOC ... that's really helpful info!!

  4. I read recently that in blindness-prevention programs in developing countries, charity workers help prevent eye damage in children by giving them two vitamin A capsules a year. Each capsule is a dose of 100,000 IU, which is apparently the upper safe limit for vitamin A intake in one day. But the fun part is that you store the excess in your liver, and can draw on those stores for a while. So these kids are set for six months (I don't think the math quite works out to optimal levels but obviously it works for saving eyesight). Vitamin A is also used to treat women with menstrual pain and heavy flow. I was able to apply that in my own life long before I found out it was a common treatment used by Third World charities.

    The fun part is that beta carotene doesn't go the same places in the body. If you need vitamin A and you can convert beta carotene well enough for it to be much use to you, you only convert as much of it as you need to get your A requirement. The rest goes not into your liver but into your bodyfat, and it stays there, which is why food-critters that eat an excess of carotenes have yellow fat when you butcher them. So if you're going to rely on beta carotene for your A--if you even CAN rely on it, and too many of us can't--then you have to keep consuming the same amounts day after day after day, and you can't afford to miss a day. Whereas with vitamin A you can afford a feast-or-famine cycle because you can store the surplus and use it later.

    1. & it looks like they (the World Health Organization) also dose at 200,000 (dose interval every 4 to 6 months). Full info found here;

      I would guess this must be a synthetic form of Vitamin A?

  5. Hi Chris,

    Off topic but I was wondering if you would consider doing a special report on saturated fat? I work in medical research and I'd love something to show to some doctor colleagues that was credible. I need something better than a one meta-analysis, something that really goes into the nitty-gritty of each study.

    Or could you point me to such a resource?

    Thanks in advance!


  6. so chris, what would be the current best practices for an individual looking to optimize their fat soluble vitamin intake?
    what are the best blood tests, would you start with knowing d levels and then tweak a & k based on d? and how does one "know" when they are at the right level for themselves? is there a perfect d, a, and/or k range for all humans?

  7. Um, am I the only one who is listening to an hour of Anthony Roberts on that link? The title is right, but there's no content on VitA. What am I doing wrong? I'm sure Rodney Dangerfield was a lovely person, but I'm far more interested in vitamins than weed use among dead comedians.

    1. Look at the time indices above. They begin at 00:58:55.

  8. Great discussion as per usual! One of the things I like most about Chris is that you can always tell when someone has a deep understanding of a subject, when most of the answers start with, "Well, it depends..."!

    I've heard it said that Kidney stones are sign of raging calcium deficiency, which sounds counter-intuitive... but the connection between high-levels of Vitamin-D and Hypercalcemia kinda makes sense!

    It was mentioned in passing, but what are generally accepted levels of vitamin a, d, and k(2) in the blood, that are considered healthy? Also, assuming blood samples can survive the journey, is there a direct to public lab that has a good reputation for testing?

    My current betacarotene (pro-vitamin-A?) & vitamin-d3 intake is 10000iu and 1000iu respectively. I've only been able to strong arm my doctor to have my vit-d3 tested, and it was 50ng/ml!

    Finally, is the "Green Pasture's Blue Ice Fermented Cod Liver Oil" the brand mentioned to look at? Since its in capsule form, how bad can the taste be?!

    1. I think you read this..

  9. Responses to thaneverbefore, Beth, Dana, SamAbroad, Darius, Lauren, Ben

    Hi thaneverbefore,

    In some cases it may be to gain more mechanistic insight, but I think it is largely because they are aimed at pharmacological interventions with the hormone forms. It is generally assumed that pharmacology is more powerful than nutrition, and there is a bias towards assuming that high-dose fat-soluble vitamins are dangerous, so targeted pharmacological interventions are appealing to many researchers. It tells us nothing about diet except offering proof of principle that the hormone forms are active. Diet affects the hormone forms, because if you don't have retinol, you can't make retinoic acid. It also offers us proof of principle about the types of interactions displayed between the fat-soluble vitamins. These unrealistic experiments, like using the hormone forms, or like injecting the fat-soluble vitamins, show us that the interactions aren't mediated by interference with intestinal absorption, a commonly cited but false explanation.

    And yes, there are mediators of hormone levels that are separate from actual vitamin intake. There is evidence that vitamin D or any of vitamin A's other molecular partners increase the conversion to retinoic acid, and oxidative stress of some types can degrade it. I'd have to do more research to offer a complete explanation.


    you're welcome!


    I think that is true to a certain limited extent, but we can convert stored beta-carotene to vitamin A, and we can also store vitamin A made immediately from beta-carotene, so it might not be quite capable of the same type of intermittent dosing you can do with retinol, but you don't need to eat it every day to prevent vitamin A deficiency, if you don't have problems with the conversion.


    Not at the moment, but I'll keep it in mind. Thanks for the suggestion. At the moment my Precious Yet Perilous article comes closest, and I have an upcoming Wise Traditions article that is a written version of my Good Fats, Bad Fats talk that will be out soon, but as to a detailed report focusing son saturated fat specifically, that will be some time coming.


    There really aren't any good blood tests. 25(OH)D is the measure of vitamin D status, and it might make sense to shoot for about 40 ng/mL (multiply by 2.5 for nmol/L), but there are a lot of uncertainties about the interpretation of this test. Serum retinol is worse, but it should be within the lab's reference range. The best test for vitamin A deficiency is poor night vision or a lag time adjusting to changes between light and dark. The best test for vitamin K deficiency is elevated undercarboxylated vitamin K-dependent proteins, most commonly osteocalcin, but I'm not sure if that's available commercially. I doubt there is a "perfect d, a, and/or k range for all humans," but if there is I don't know what it is and I doubt anyone else does.


    As I said in the text right above the link, it starts an hour in. Sorry for the confusion!


    Thanks for the appreciation. Regarding blood levels, please see my response to Darius. That is the cod liver oil that I use. I use the liquid oil. The capsules aren't that bad, but some people have a problem burping up the taste. I have heard that this problem is less common with the fermented oil, but your mileage may vary.


  10. Hey Chris, thanks for the response.

    Forgot to mention earlier, I also appreciate the ToC's you've been posting for your interviews.

  11. Chris,

    I enjoyed your appearance on the show. Regarding the upper limit for Vitamin A: have you seen the EUROSCAN vitamin A trial report? 300,000 UI retinyl palmitate per day for a year, followed by half that dose for an additional year!

    The suprising part is that many patients were able to take that dose: "of the 647 patients randomly assigned to receive retinyl
    palmitate only, 167 (25.8%) stopped treatment"

    1. Thanks thaneverbefore, I'm glad they're helpful.

      Hi Arby, No I hadn't seen that. Thanks!


  12. Bravo. Great interview and thanks for all the usable information.

  13. Hi Chris,

    I'm currently working on a lifelong anxiety problem. I was wondering if you could help me with a few questions for my treatment regimen. So far the only treatment I have found successful is sleep deprivation. The difference is a real night and day in my personality / functioning so I'd like to nail this thing if possible. Any help you could give would be very much appreciated.

    The plan: Livers/Eggs/Sweet Potato for A, Supplemental D3 + sunshine (after a blood test), K2 from Natto / Kimchi / Kefir/Yogurt, Zinc supplements or once weekly oysters, Magnesium citrate, & a multivitamin. My diet will mostly be sweet potatoes, eggs, white rice, canned tuna, kale/spinach, and cream (with once weekly liver + oysters).

    I live in Thailand and Calf/Beef liver aren't available for me; nor is cod liver oil. Are chicken or pork livers sufficient substitutes? I know they have about 1/5th the vitamin A, and lack most of the copper. Would eating these livers daily be advisable for a period of time?

    Have you expressed thoughts about bolus dosing of Vitamin D3 supplements? (35,000-50,000) once per week compared to 5,000-7,000 daily, for people with deficiencies?

    Since Zinc/B12 are water soluble, why is it that the vegetarian tribes Weston A. Price found only required Oysters once per month? Wouldn't they excrete the excess that day? Is there a storage mechanism for water soluble vitamins? More pertinent: Should I take zinc daily or rely on once weekly oysters to meet my needs? Should I consider a Copper/Zinc supplement since I don't have access to beef liver for copper?

    Whats the deal with the RDA for Vitamin E? Unless you eat Sunflower seeds, Almonds, or 5-10 servings of greens daily, you simply can't meet the RDA.

    I really enjoyed your lecture on Molecular Degeneration and Heart Disease. My Dad just had a quadruple bypass (yet no heart attack), so I was able to give the recommendations you lay out to him. It was very much appreciated. Do you have any thoughts on Dr. Klevay's copper deficiency hypothesis of heart disease?
    (I am also curious to see if including copper in my diet would reverse or prevent further growth of my apical hypertrophic cardiomyopathy.)

    Thank you for whatever answers you can provide and the work you are doing. As an aside: your work on the China Study helped get me out of Veganism & Fruitarianism.



  14. Excellent as always Chrissyguns.

    Regarding the fermented cod liver oil, why do you prefer that to the regular stuff? And how is it fermented anyway? I always thought only carbs could be fermented. I assume it is bacteria breaking down some of the fats in it?? Are you not worried that this could damage the delicate omega 3 PUFAs in it?

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