Vitamin A and pregnancy. Should you be concerned? Hi. I’m Dr. Chris Masterjohn of chrismasterjohnphd.com. 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 and pregnancy. In the last few episodes, I’ve been talking about vitamin A toxicity, but there are concerns that too much vitamin A in pregnancy, even at levels that are not toxic to the mother, could cause birth defects in the baby. This is based on several things. First of all, we know from animal experiments that both vitamin A deficiency and vitamin A toxicity will cause birth defects. Second, there was a study published in 1995 that looked at what do women consume now for vitamin A, and then looked at in the future what happens to the risk of birth defects. That’s called a prospective study because they looked at the vitamin A first and looked at the outcome later. And that showed that women who consume more than 10,000 IU a day in the first eight weeks of pregnancy had an increased risk of birth defects. There were a number of other studies published that showed that much higher vitamin A intakes had no effect or were even associated with lower risk of birth defects, but they were all retrospective, which means that after the birth defects were determined, then they asked the mothers how much vitamin A did they eat leading into their pregnancy. And those are considered to have a greater risk of bias and to be less accurate because it’s — there’s more — you’re more likely to be biased or to not remember correctly what you ate before than to know what you’re eating now and to correctly report what you’re eating now. The 1995 paper got a lot of criticism because there were a lot of things that seemed to be off about the paper. And I actually did a write-up of this that I’ll link to in the description of this episode. It was a sidebar in an article that I wrote called “Vitamins for Fetal Development.” So, I’ll refer you to that article if you would like more information about the controversy. Suffice it to say that there really isn’t very good data about whether we should be concerned about vitamin A intakes around 10,000 IU leading into the first eight weeks of pregnancy, but there’s also not that great reason to get more than that if there are no signs and symptoms of vitamin A deficiency in the mother. So, the way that I look at this is, you should cap, if you are of childbearing age and planning to get pregnant in the next year, you should cap your vitamin A intake at 10,000 IU per day and keep it below that, unless you have a very good justification for doing otherwise. And the reason is simple. If you look at traditional diets, there are some outliers where there are some traditional diets where the vitamin A intakes were higher than that. For example, the Greenland Inuit. There was one report of them consuming around 50- or 60,000 IU per day, but overwhelmingly across the board traditional diets didn’t go anywhere near that high. If you think about eating liver once or twice a week, and eating three eggs a day, and eating three servings of high-quality dairy every day, which are going to be your major sources of retinol, the animal form of vitamin A, you’re not going to go over 10,000 IU per day. And if you look at the traditional use of cod liver oil, you had some cases where traditionally people used it in tablespoon amounts when they were sick, but they never did so for more than a few days, and then you had other cases where cod liver oil spread across the world becoming very popular in medicine using it in amounts of one or two teaspoons a day for a period of weeks or months, but not using it even in those doses for an extended period of years. The ability to take a vitamin A supplement providing 10, 20, 30, 40, 50 thousand IU of vitamin A per day is relatively speaking in human history a very new thing, and it doesn’t have a great track record to speak of whether it’s safe or not to take during pregnancy. So, the way that I look at it is for a woman of childbearing age who has a plan at some point in the next year to become pregnant and doesn’t have any signs or symptoms of vitamin A, of vitamin A deficiency, then limit the vitamin A intake primarily to foods rather than supplements. A supplement of liver capsules or cod liver oil I think is fine, but just keep the total under 10,000 IU per day. For someone who has signs and symptoms of vitamin A deficiency who has blood work justifying a concern about vitamin A deficiency, then I think it’s okay to go higher, but use the minimal effective dose to resolve those and try not to go higher than you need. Not because I’m convinced that doing so will cause birth defects, but because why take the risk when there’s no theoretical benefit to come with it. 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 ancestralsupplements.com. 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. 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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 chrismasterjohnphd.com/masterpass 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 taureanonlinemixing.com. All right, I hope you found this useful. Signing off, this is Chris Masterjohn of chrismasterjohnphd.com. This has been Chris Masterjohn Lite. And I will see you in the next episode.