Summary
Based on my research, I think it’s reasonable to assume that essentially all animal fat will have at least some vitamin A content, even when some sources of nutritional data claim there is zero — which, especially with the USDA database, is sometimes just an assumption and not an actual empirical result from any test for retinoid content.
So that means that the way to get closest to excluding all Vitamin A from the diet — not that I recommend that — would be to exclude all animal foods, including dairy and eggs — and I wouldn’t recommend that for this and other reasons.
Unless you’re eating a diet that also puts you in danger of severe malnutrition like a diet of only white rice — in which case the deficiencies in protein and fat will probably be the bigger problem — no one should need to worry about not getting vitamin A in the diet (and this also ignores your body’s pre-existing vitamin A stores, which you will have from birth from the vitamin A in breast milk. So even if you still believe vitamin A is necessary or essential, no one who is eating at a level above severe malnutrition should need to worry about it, because it’s nearly impossible to avoid eating at least some vitamin A.
So that means, as long as your eating some animal foods, like meat or dairy or eggs, you don’t need to worry about getting enough vitamin A. And in the modern world, all we need be concerned about is getting too much vitamin A.
Post
The Vitamin A content of beef and of meats / animal foods, in general, has been made confusing by conflicting (or erroneous or missing) information from various sources of nutritional analysis.
There are some sources that say there is no Vitamin A in beef or in particular cuts of beef — like the USDA database results that are referenced by the top result of google searches for “Vitamin A in [X]” — but if you look at the fine print you’ll sometimes find that this is an assumed or inferred value — in other words, they haven’t always actually tested the VA content of every single food or cut of meat.
Meanwhile, there are other sources that say there is anywhere from 50 to 75 IUs of VA in lean beef. There are also studies done for the cattle industry to determine how cattle feed affects Vitamin A levels in the blood, liver and fat — they took fat samples from live cattle and sure enough, the fat always had Vitamin A.
Furthermore, there is reported VA content in almost all fish, poultry and land animal meats. And generally, the fattier the cut, the more VA it will have since VA is stored in the fat since VA is fat-soluble.
Further still, there has been research done to specifically analyze the Vitamin A content of human tissues and VA is found in essentially all of them. There are even trace amounts in found in muscle tissue, which is possible because (I assume) of intramuscular fat and because all cells have lipids where VA could be found.
Whether they are a herbivore getting carotenoids or carnivore eating those herbivores (with carotene and retinol in their fat), every animal is probably getting at least some VA when eating natural food in the wild.
In fact, having VA in lipids and adipose tissue seems to be universal to the entire animal kingdom. And it would be strange if some animals had VA in their fat, but other, closely related species didn’t. Of course, they all have their largest VA stores in their livers and they have way less in the fat — but that’s just another reason to assume all animals have a similar enough VA regulation system to assume there is at least some VA in all animal fat.
So my assumption has been that all animal foods will have at least some VA and therefore I will rely on my own reaction to a particular food as the final arbiter of how much “VA activity” it has.
And I’ve found that the best way to test one food is to have an otherwise consistent diet with consistent symptoms (or no symptoms) and then add just one new food for a day and then observe how my body reacts over the next 24 hours or more.
Early on, I experimented with moving towards a mostly beef diet as with the Carnivore Diet, but it made me feel worse. And I suspect it was getting more VA (and also possibly consuming more retinoic acid). And I found I felt best when I started eating the leanest beef.
Unfortunately, less fat also tends to be less satiating, but by including a staple white starch (e.g. white rice, white corn flour, white potato) at every meal, I have no problems with satiation. So I do not think there is a need to cut out all or most carbohydrates. In fact, I assume they are helpful.
I want to expand on this further in the future because I suspect there are a lot of people who are getting more VA than they realize because it’s unlabeled, or mislabeled, or inaccurate, or they are forgetting about foods that could potentially have retinoic acid (RA) even if there’s zero retinol.
So, as Genereux has pointed out in his work, presumably all that is required to initiate the oxidation of retinol is heat and oxygen.
So I consider it possible that there could be RA in any food which has retinol naturally but has been processed in a way that exposes it to heat and air — e.g. pasteurized milk, pretty much all dairy products such as cheese or yogurt or butter, dried meats such as salami or jerky, rendered fats such as tallow, lard, etc.
And in addition to that theoretical understanding, I have had food reintroduction experiences that seem to confirm that certain foods and certain methods of cooking seem to have significantly amplified “retinoid activity” compared to other forms or cooking methods — and I suspect this is due to the oxidation of the retinol in a food into retinoic acid before even consuming it (i.e. it happens while its being stored or processed or cooked).
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