Vitamin A Toxicity – What You Need to Know

This post contains affiliate links

  Vitamin A Toxicity - What You Need to Know - Holistic Squid

Naomy writes…

I’m still confused and concerned about the Vitamin A during pregnancy and causing birth defects since I’m only 5 weeks pregnant… I’ve read various and conflicting information.

I want to start taking a blend of fermented cod liver oil/butter oil and not sure if I should take that AND continue taking my prenatal vitamins. Will that be too much Vitamin A?

I understand or think that it’s different Vitamin A (prenatal Vitamin A is synthetic, and cod liver Vitamin A is natural). So would I be taking too much Vitamin A if I take BOTH prenatal vitamins and cod liver oil?

Great question.

Why is Vitamin A So Important Anyway?

Vitamin A (the kind found in animal sources) is one of several fat-soluble activators that is necessary for the assimilation of minerals in the diet.  According to Sally Fallon, Vitamin A is the “concert master for a developing fetus.”  Vitamin A is also essential for eye health, immune function, healthy skin, and brain function.

 The Difference between Vitamin A and Carotene

There are two forms of vitamin A: preformed vitamin A (also known as retinol or retinoids) and carotene.

Basically, animals sources such as cod liver oil, liver, eggs, whole milk, cream and butter contains actual, preformed vitamin A.  Whereas carotene is a precursor found in deep green and yellow or orange vegetables which, under ideal circumstances, your body can convert into vitamin A in the upper intestinal tract.

Why Not Just Eat a Bunch of Carrots and Call it a Day?

The issues with carotene are:

1) You need to eat a large quantity of carotene-rich fruits and vegetables to meet your daily requirement and

2) The carotene is not well converted in infants and children, individuals who eat a low-fat diet, or those suffering from diabetes, hypothyroidism, pancreatic disease, or digestive issues including diarrhea, or celiac disease.

Other things that can prevent conversion of carotene into vitamin A include, “Strenuous physical exercise, excessive consumption of alcohol, excessive consumption of iron (especially from “fortified” white flour and breakfast cereal), use of a number of popular drugs, excessive consumption of polyunsaturated fatty acids, zinc deficiency and even cold weather” (Fallon, Vitamin A Saga).

So the best way to get vitamin A is through food sources of the straight stuff: Cod liver oil, liver, eggs, whole milk, cream and butter.

Let’s Clear Up the Confusion about Vitamin A and Toxicity

There is some major conflicting information regarding the toxicity of Vitamin A, and as a result, the recommended dosages conflict as well.

In 1995 a study from the New England Journal of Medicine, Teratogenicity of High Vitamin A Intake, concluded that preformed vitamin A taken in excess of 10,000IU per day by pregnant women was linked to birth defects.  This single study received a great deal of attention, and consequently The FDA currently recommends that pregnant women get their vitamin A from foods containing beta carotene and no more than 5,000 IU of preformed vitamin A (if any) per day.

However, according to a recent edition of the Merck Manual (a well respected medical text book):

Acute toxicity [of vitamin A] in children may result from taking large doses (300,000IU); it manifest as increased intracranial pressure and vomiting, which may lead to death unless ingestion is discontinued.  After discontinuation, recovery is spontaneous, with no residual damage. Only two fatalities have been reported.  Within a few hours of ingesting several million units of vitamin A in polar bear or seal liver, arctic explorers developed drowsiness, irritability, headache, and vomiting, with subsequent peeling of the skin. Mega-vitamin tablets containing vitamin A have occasionally induced acute toxicity when taken for a long time.

Chronic toxicity in older children and adults usually develops after doses of >100,000IU/day have been taken for months. In infants who are given 20,000-60,000IU/day of water-miscible vitamin A, evidence of toxicity may develop within a few weeks. Birth defects have been reported in the children of women receiving 13-cis-retinoic acid [commonly known as Accutane] for skin conditions during pregnancy.

From the Vitamin A Saga, Sallon Fallon reports, “The US Recommended Daily Allowance of vitamin A is currently 5,000 IU per day (and may possibly be lowered to 2500 IU per day). From the work of Weston Price, we can assume that the amount in primitive diets was about 50,000 IU per day, which could be achieved in a modern diet by consuming generous amounts of whole milk, cream, butter and eggs from pastured animals; beef or duck liver several times per week; and 1 tablespoon regular cod liver oil or 1/2 tablespoon high-vitamin cod liver oil per day.”

So what we have here are several conflicting reports which are clearly not individually illuminating all of the facts, otherwise they would be on the same track. Which brings us to…

The Importance of Vitamin A/Vitamin D Ratios

Vitamins A and D work synergistically in their various important functions in the body.

The problem with most commercially available cod liver oil brands is they are processed and treated so most of the naturally occurring vitamins are removed. The Vitamin A and D are then added back in with too little vitamin D in ratio to the added vitamin A.

Because of this common practice, many health expert warn against cod liver oil, but in fact, they should be warning against processed cod liver oil. In it’s natural form, cod liver oil is a perfect natural supplement of Vitamins A and D.  The ideal ratio is approximately 1:5, D to A.

Is there a Difference between Naturally Occurring and Synthetic Vitamin A?

Many scientists would argue that a chemical compound is a chemical compound.  I see their point. However, vitamins that occur in nature are seldom isolated and instead are accompanied by other vitamins and potential co-factors.

Case in point: Vitamin A needs vitamin D. The study done in the New England Journal of Medicine found birth defects mostly in mothers taking supplemental preformed vitamin A, not food-sourced preformed vitamin A.

The point is, that while a synthetic vitamin and natural vitamin may look the identical when isolated under a microscope, whether or not they bring friends to the party makes a big difference in how each functions in the body.

Best Sources of Vitamin A

So.  Having covered all of that, the best sources of preformed vitamin A are:

  • Fermented Cod Liver Oil or (second choice) Unprocessed Cod Liver Oil – dosage below.
  • Liver from pasture-raised, healthy animals – 1-2 times per week.
  • Raw, unpasteurized milk or cream – 1 quart of milk/day for pregnant or nursing moms
  • Eggs from hens raised on sunny pasture – 2 or more per day

Remember, while carotene can provide Vitamin A through conversion, it is not a reliable source.  There is no need to worry if you eat some squash or carrots with your eggs and liver since carotene is not known to cause toxicity in large quantities or in combination with preformed vitamin A.

The Weston Price Foundation recommends the following dosages for fermented cod liver oil***:

  • Children age 3 months to 12 years: 1/2 teaspoon or 2.5 mL, providing 4650 IU vitamin A and 975 IU vitamin D.
  • Children over 12 years and adults: 1 teaspoon or 10 capsules, providing 9500 IU vitamin A and 1950 IU vitamin D.
  • Pregnant and nursing women: 2 teaspoons or 20 capsules, providing 19,000 IU vitamin A and 3900 IU vitamin D.

***NOTE – Read here for clarification on dosages of fermented cod liver oil.

Where to buy fermented cod liver oil (I prefer the orange flavor).

Would I be taking too much Vitamin A if I take BOTH prenatal vitamins and cod liver oil?

Coming back to Naomy’s original question, the ideal practice would be to take the recommended dose of fermented cod liver oil, eat foods rich in vitamin A, and get plenty of sunshine (if possible).

Prenatal vitamins are not recommended for women with a healthy, complete diet. You can read about the ideal diet during pregnancy here.

If you DO choose to supplement while pregnant, it may be best to figure out what nutrients are lacking in your diet and then choose targeted supplementation instead of a bucket prenatal. For example, get your vitamins A and D through cod liver oil but take additional folate if you do not eat liver at least once or twice per week.

Confusion cleared?  If not, ask below!

photo credit: bradley j, flickr creative commons.

Like What You've Read?
Subscribe to Holistic Squid by email and never miss a post!

Disclaimer and Affiliate Endorsement Information

Related posts that may interest you


  1. Kendahl @ Our Nourishing Roots says

    This is a great breakdown! Thanks for clearing this all up. I have had a LOT of pregnant and breastfeeding women ask me about this, specifically.

  2. Heather Brandt says

    I guess I’m still confused…I’m taking prenatals by Innate Response Formulas and take 1 tsp of cod liver oil a day from Green Pastures. I don’t eat organ meat every week (though that is something we’re hoping to start by the end of the month). Should I go ahead and go up to 2 tsp of cod liver oil daily since we are TTC or not?

    • says

      Hi Joanna – I agree. It IS a tons of capsules, especially if you are pregnant or nursing. Personally, I just can’t get FCLO down any other way. My kids, however, (ages 1 and 5) take it happily when mixed with elderberry syrup or a orange flavored vitamin C. They ask for more. Some people like to chase it FCLO with raw milk or kombucha or juice. Let me know if you find a way that works for you!

    • Shellee says

      I keep mine in the fridge, and scoop out with a butter knife. Then scrape it off on the back of my teeth. Next swallow like a pill with large glass of water. Good luck!!

  3. Zoe says

    Great article! How do you feel about New Chapter Organics Perfect Prenatal vitamins since they are based on whole food vitamins? No doubt it always is the most beneficial to get your vitamins from real food, however realistically with our busy lifestyles it can be challenging to ensure we get all our needed vitamins.

    • says

      Hi Zoe – I recommend New Chapter for my patients who are trying to conceive, are pregnant or nursing and don’t have a completely ideal diet.

      • Sara says

        so…if a person takes New Chapter, they should still take FClO while TTC? I take New Chapter and have a decent diet but not perfect.

        • says

          Hi Sara – Yes. You should take the fermented cod liver oil in addition to the food based prenatal vitamins. Even with a prenatal that includes DHA (New Chapter does not), I would still take the FCLO.

          • Janelle says

            Ahh Thank you! I was looking for an answer about taking prenatals with DHA and taking the FCLO. I would assume that taking post-natals with DHA and taking the FCLO would also be ok… Is that assumption be correct?

          • Mindy says

            My question exactly, Sarah! Thanks for asking, and Emily thanks for the clear and direct response!! I’m thrilled to hear New Chapter is your recommendation for those of us with not quite perfect diets! :)

      • gianna says

        Hello, I take the New Chapter prenatals, however, it states 5000 IU of Vitamin A (and you take it 3 times per day… ) this results in 15000IU per day of Vitamin A. I have been told this is too much Vitamin A and can cause the birth defects, as the article above seems to agree. What are your thoughts on this, since you recommend this prenatal?

  4. mya says

    Would it be too much to take fermented cod liver oil/ high vitamin butter and eat raw grass fed beef liver? What would be the right amounts for an adult and an 11yr old boy? I don’t want to overdue but would like to add raw liver to our diet along with the cod liver oil/high vitamin butter.


  5. mya says

    Would it be too much to take fermented cod liver oil/ high vitamin butter and eat raw grass fed beef liver? What would be the right amounts for an adult and an 11yr old boy? I don’t want to overdue but would like to add raw liver to our diet along with the cod liver oil/high vitamin butter.


  6. Madre' says

    Hi Emily, I’ve had vitamin A poisoning as a teenager from Accutane that was given to me for my acne problem. I have had health issues ever since, but my question is if you have had vitamin A poisoning once before does it make you sensitive after for vitamin A? Should I be taking cod liver oil at all? I’ve lost all belief in vitamins so I don’t take anything anymore. I realised that it should come from the food we consume rather than a synthetic source.

  7. says

    I’m so glad I came to your site to search for answers about liver consumption during pregnancy Emily! Thank you so much for writing this article. When I was reading all over mainstream pregnancy sites that eating liver is a pregnancy no-no, it just did not sit right with me. Now I can enjoy my homemade chicken liver pate in peace!

    I <3 HolisticSquid!!!!

  8. Elizabeth says

    I am taking the Garden of Life RAW whole food based prenatal vitamins, 2-3 “Pills” of liver a day, and a teaspoon or 2 of unprocessed Cod Liver Oil daily. Is this overdoing it?

  9. Claudia says

    This stuff is really expensive! I have three children and a 4th on the way. I really want to buy it and give it to them and myself. Can anyone give me an idea of how long this bottle will last me??? Also curently I take vitamin D drops (2,000iu) a day and give my children 800iu a day… is it pointless to take these drops if its not combined with something that has vitamin A in it as well and b/c its synthetic?

    • says

      Hi Claudia – Thanks for your comment. An alternative to FCLO would be to take fish oil, vitamin D, and eat liver (or take liver pills). Hope that helps!

  10. Katie C says

    Thanks for your post! I have another question though! My family has to cut back on our food budget and I was wondering if I could make frozen liver pills to replace the Cod Liver Oil in our diet. Would this be an appropriate substitution? Thanks for your help!

  11. kasey says

    Thanks for writing this, I just wanted to clarify what I read in the comments, I’m about 2 months along and want to start taking FCLO, you said it’s safe to do that with the new chapter prenatals , is it also save to have about an oz of liver each day, because I’m just dreadful at making things to meet the 3 oz twice a week? Thanks

  12. haley says

    I’m confused to boot :( I take 3 oz raw liver pills a week and take megafood baby and me herb free as my prenatal. I was taking fclo/ hvbo 1.5 teaspoons a day from week 6 on (I’m 11 weeks now) my food aversions are and became so strong i could no longer tolerate the smell and texture and put the oil into capsules. It’s very tedious and I’m at the end of my bottle. I’m looking for an alternative to fclo. Green pastures is the only brand that isnt synthetic, but totally unpalatable to me right now. Do you think 3 oz of liver a week is enough vitamin a? I also add pastured yolks to my smoothies and drink raw milk, but not a qaurt a day. I have serious fclo guilt, it’s silly but when I know it’s the best but cant stomach it, let alone barely afford it, it’s hard to feel good about my efforts. Is no clo better than taking one with synthetic vitamins added? Say, nordic naturals? I’ve read your post the outlandish alternatives to a prenatal, but with my aversions I can only do so much. I love your blog, thanks for your input!

    • Jenny says


      Have you tried Green Pasture infused coconut oils? I bought the banana flavor and mix it in smoothies. I can’t taste it at all!

      • haley says

        I have heard of it, and I’m willing to try it. I have always wondered what the dose would be for pregnancy. If the fclo is 2 teaspoons, how many teaspoons of the coconut oil blend would I need to equal the fclo? That’s what’s stopped me in the past from going with that one. How much do you put in smoothies when you can’t taste it?

        • Jenny says

          I contacted Green Pasture for vitamin A amounts in the infused oil. There are approximately 1000-2000 iu’s per 1/2 tablespoon. I use a food processor thanks to not owning a blender to mix a smoothie for several days. I put in about 1/2 cup yogurt, 3/4 cup strawberries, 1/2 cup blueberries, 1/2 cup orange juice, 2 bananas, and about 3 Tbsp infused cod liver oil. I also add milk until it’s smooth. If it’s too thick there’s these bits of cod liver oil that you can bite into. It’s really a mild flavor compared to the regular oil but I’m a total cod liver oil puss!

        • Jenny says

          This is a really important article to read about nutrition in pregnancy with FCLO. At the bottom she mentions the it’s very important to balance fat when talking FCLO otherwise hemorrhage can occur. However I spoke with Dave Wetzel the owner of Green Pasture and he says the butter oil in the infused coconut oil blend balances it. I still think it’s wise to eat plenty of eggs if taking FCLO though.

    • says

      Don’t feel guilty, just do the best you can. If you can’t handle the FCLO even in the caps, I would do regular fish oil – like this one: , plus Vitamin D and liver pills.

  13. Sarah t says

    I have read through all your great posts and am still a little confused. I am taking pre pregnancy vitamins. Having looked at the ingredients there is no listing of Vitamin A at all (there is obviously Vitamins D, E, C, B6 Folic Acid). Would it therefore be safe to take FCLO and if so in what quantity?

    Thanks so much for a great article!

  14. Sarah t says

    Hi, Sorry I have just noticed my vitamins do contain ‘beta-carotene – 2mg’ – would I still be ok to take FCLO?

    • says

      Hi Sarah – Thanks for your question. Beta carotene isn’t ‘true’ vitamin A. Fermented Cod Liver Oil contains the right balance of D and A, so that A isn’t toxic. Hope that helps!

  15. C says

    Hello, I am taking the Garden of Life RAW whole food based prenatal vitamins -3 a day, and taking FCLO 2 teaspoons a day and Butter oil-1 teaspoon a day …is this over doing it ?

  16. Alison says

    ^^ Bumping the above post ^^
    I’m also taking Garden of Life RAW Prenatal and am interested in knowing how much FCLO to take daily? Thanks!!!

  17. Amber Nelson says

    I am 30 weeks pregnant and have been taking garden of life raw food prenatals off and on. I just got a bottle of fermented cod liver oil/butter oil blend that I plan on taking daily from now on. Can I continue to take my raw food prenatal along with the FCLO/HVBO blend or should I alternate days? I live in Arizona. When we do go outside, its not for long and if we swim we use our homemade sunscreen. Thank you!

  18. Sara says

    Hi! Like others, I am still confused. The Vitamin I will be taking is MegaFood Women’s Once Daily (CA Blend), which is food-based. It has 2500 iu Vit A (alpha and beta carotine, and mixed carotenoids — all from carrots, I think). I know FLCO is supposed to be best, but to be honest I am nervous about being sensitive to histamines and having a reaction and I am not sure I could stomach it.

    You said that usually there is too little Vit. D for the amount of Vit. A in most cod liver oils. So would a A:D ratio of 850:400 or about 2:1 be not as problematic? I am looking at Carlson’s Cod Liver Oil, which I know is not ideal but is hopefully better than not taking any CLO. There is the liquid (with the aforementioned amounts and ratio) and then also a softgel, with a A:D ratio of 5:1 (and it says the A and D are from cod fish liver, plus some synthetic :/ ) I think I am going to call the company to see the differences between the two products (aside from the softgel vs liquid). The liquid has much more EPA and DHA than the gels, so I would prefer that unless the A/D is more problematic.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>