What you’re getting yourself into
A rundown of the essential minerals and vitamins that are potentially deficient on the carnivore diet, and whether you should consider supplementing them.
It’s natural to expect that a restrictive diet where you’re confined to playing with a handful of ingredients, would need to be fortified by an armada of supplements.
When you eliminate entire food groups, there are consequences to be paid. Perhaps not immediately, since humans have shown the remarkable capacity to survive on threadbare nutrition over extended periods of time. This is why some vegans still make it past the first year.
But the smart ones do their due diligence, assess the inevitable inadequacies of a plant-only diet, assemble a kitchen cabinet that can plug the gaps. For their wisdom, they might get a little further than the zealous defender of the animal kingdom who thinks that he can get by on quinoa and lentils.
But eventually, there’s a price that needs to be paid when you’re a carnivorous creature roleplaying as a herbivore. Even the smartest vegans with the means to afford the best supplements, only get so far. You only have to look at the never-ending conveyor belt of vegan celebrities that relapse and describe their first bite of meat like they’re dropping LSD.
The carnivore diet shares the extremes of a vegan diet, just on the opposite end, and without the dogma of sticking to the rules no matter the cost, and without excommunicating anyone who decides to break off from the diet. But nevertheless, it would be fair to be cautious of the consequences of eliminating all plant foods.
I have tackled this topic in an article already, but that was four years ago, so I’ll be able to add more nuance to my last analysis of the Reference Daily Intakes (RDIs)on carnivore.
So let’s get into the prime suspects that are usually offered up when talking about the nutritional deficiencies of a carnivore diet.
Why Fiber Is Not Essential
I think it’s worth squashing this right out of the bat, because contrary to the adamant claims of dietitians, fiber is not an essential nutrient. If you don’t have fiber in the diet, you’re going to be fine as long as your diet isn’t made of twinkies and french fries.
But since this is a point of sore contention, I’ll run through the functions of fiber, and why they’re surplus to requirements on carnivore.
Lowering Blood Sugar – Any effect on glucose control is mild, and not relevant when you’re not eating those carbs that spike blood sugar in the first place.
Lowering Cholesterol – Fiber can lower cholesterol, but that’s only a benefit if we assert that having normal levels of cholesterol is a bad thing. And we don’t have the evidence to back up that claim.
Increasing Satiety – Fiber doesn’t increase satiety. Eating a ton of indigestible sawdust can give you the feeling of fullness, but it’s only temporary, because it doesn’t restore the energy deficit that spawned the hunger in the first place. Satiety means meeting your energy needs, and fiber is indigestible.
Assuring Regular Bowel Movements – The idea that fiber is necessary for healthy digestion is nonsense. There’s been research showing that a zero fiber diet actually cures constipation. This makes intuitive sense, because fiber is indigestible junk with the potential to pack up the large intestine.
Carnivore, on the other hand, is the ultimate low residue diet that rarely gets past the small intestine. So you might have to settle for only sitting on the throne once a day, but that’s not a bad thing.
Feeding The Microbiome – Fiber does provide fuel for the gut bacteria by providing butyrate via fermentation. But butyrate can also be generated from fats like butter, which is literally named after it. Then there is the main ketone, beta hydroxybutyrate, which naturally contains butyrate. The collagen in meat can also be used to feed the gut bacteria.
The carnivore diet isn’t short of options to keep the microbiome blooming. And because it’s also low residue, low in toxins, and nutrient dense, it’s flat out the best option for overall gut health.
So you can pass on fiber without guilt. The benefits it has only serve to ameliorate the harmful effects of a high carb diet.
Summary – Fiber is not essential, or beneficial in a zero carb diet.
Phytochemicals
These are compounds that are exclusively found in plants, and have various purported benefits in fighting inflammation, oxidation, and other longevity channels. But not only are they not essential, they are also found in considerable quantities in grass-fed red milk and dairy.
Which effectively describes all red meat, since all cattle spend the majority of their lives on grass. So you’re not missing out on those precious phytonutrients when you drop the blueberries that you’ve been sprinkling on your oats every morning.
As a bonus, carnivore allows you to get these phytonutrients without all the accompanying defence chemicals and antinutrients that are packed in these plants. That’s the beauty of allowing ruminants to use their intricate digestive system to process plant nutrition so you get the healing without the inflammation.
Summary – Phytochemicals aren’t essential, but grass-fed red meat and dairy can scratch that itch.
Vitamin C
This is another potential deficiency that springs in the minds of concerned family members, fueled by the fact that googling the Vitamin C content of red meat usually returns with a big fat zero. This is incorrect, as red meat has been shown to have around 2.56 mcg of Vitamin C per gram of red meat.
But that’s not an awful lot of Vitamin C, and eating two pounds of steak a day, that grants you a 2.3 mg intake that’s well short of the requirements of 10 mg you need to prevent scurvy, or the 75-90 mg recommended for its full antioxidative potential.
But there is a caveat with this, that’s been born out by the fact that sailors with scurvy used to be cured with fresh meat. The myth that a diet of meat can lead to scurvy comes from the afflicted sailors who ate dried meat on long voyages, which will naturally be drained of much of its nutrients.
Vitamin C competes with glucose, and often gets wasted in large amounts on a high carb diet. The antioxidative function of Vitamin C gets overridden by the two natural antioxidants that the body evolved to use after losing the ability to synthesise Vitamin C: glutathione and uric acid.
The requirements on a zero carb diet is likely going to be much lower, measured in the micrograms rather than milligrams. But if you’d rather be cautious, or you’re including plenty of milk in the diet, which will contain carbs, then the following animal foods will have decent levels of Vitamin C.
Per 100g serving
- Beef spleen – 45.5 mg
- Beef thymus – 34 mg
- Beef liver – 25 mg
- Salmon roe – 16 mg
- Chicken giblets – 13 mg
- Beef brain – 10.7 mg
- Beef kidney – 9.4 mg
Summary – Vitamin C is essential, but you can make do with much less on carnivore as long as you’re not having to digest large amounts of carbs in the form of milk.
Vitamin E
As an antioxidant and a supporter of the immune system, Vitamin E comes part and parcel with talk of longevity. The daily requirement is 15 mg. Seeds and seed oils are prime sources of Vitamin E, while animal foods are comparatively low.
Ground beef, for example, only has 0.1 mg per 100 grams. So getting 1kg across the day would get you to 1 mg, 1/15th of the way to the RDI.
This might be a cause for concern, but it’s worth adding that the primary role of Vitamin E is used up on the foods that it normally accompanies. Seeds and seed oils both raise oxidative stress due to the brittle nature of polyunsaturated fats. They need antioxidants to be somewhat tempered, which can come in the form of Vitamin E.
Without seeds and seed oils, the oxidative load of the diet is significantly reduced. To add to that, a carnivore diet provides an abundance of the precursors for glutathione, the body’s chief antioxidant that does far more than an exogenous aid like Vitamin E.
But if you’re still worried, 100 grams of salmon roe gets you 66% of your daily Vitamin E requirements, 200 grams of salmon filet gets you 16%, and 100 grams of eggs has 2.6 mg.
Summary – Vitamin E is essential, but the amount needed on carnivore is also much lower due to its low oxidative load. If you’re still worried, just eat more eggs.
Vitamin K1
Vitamin K is an essential vitamin that’s needed for processes like blood clotting and bone growth. Vitamin K1 is the “plant version” that’s typically found in green vegetables. The requirement is pegged at 1 mcg per kg of bodyweight.
Beef does have some Vitamin K1, so it’s not a plant-exclusive as often thought. Just like phytochemicals aren’t plant-exclusives. If a cow is eating grass, and the grass contains plant nutrients, many of those nutrients are going to be found in the meat.
Admittedly, there’s not a stratostrophic amount of Vitamin K1 in steak, at around 6 mcg in 1 kg. Egg yolks contain considerably more, at 7 mcg in 100g, but that’s still well short of the daily requirements.
Fortunately, there’s a ready-made animal-exclusive alternative in Vitamin K2, that fulfills the same functions.
While being much better absorbed than plant-based K1, getting distributed more evenly across the body, adding cell differentiation as a bonus feature, and even having effects beyond the Vitamin K cycle.
Lean meats are going to be quite low in Vitamin K2, but anything with a decent amount of fat is going to be stacked.
Two egg yolks gets you 120% of your K2 requirements
100 g of beef liver gives 184%
100 g of medium fat ground beef is 9.2%, but full-fat would assumedly be higher.
So in a twist that’s fast becoming repetitive, discussing a potential nutrient deficiency on carnivore actually leads to another great reason to adopt this diet.
Summary – Vitamin K1 is technically essential, but animal foods have plenty of Vitamin K2 that does the same thing, but better. There’s no cause for concern here.
Omega 3
An essential fatty acid that plays a role in brain function, maintaining the cardiovascular system, and fighting inflammation. There are no strict recommendations, but intakes of 250-300 mg of Omega 3 is generally suggested.
Sourcing this is not necessarily a carnivore problem, seeing as the bioavailable sources of Omega 3 are found almost exclusively in animal foods. Plant Omega 3, known as ALA, converts to the bioavailable EPA and DHA by as little as 0.01%.
100 g of eggs contain 100 mg of Omega 3, while the same amount of salmon contains a whopping 4 g.
Some people constantly espouse the virtues of grass-finished beef due to its superior Omega 3 content, but a 100 g serving of grass-finished steak only gets you 14 mg. So rather than shelling out on the finest wagyu burgers, it would be practical to occasionally include some fatty fish like salmon or mackerel, alongside eggs.
What I’d strongly recommend against, is the thought of supplementing with fish oils to raise your Omega 3 levels. For one, the primary benefit of Omega 3 is likely going to be in its opposition to the pro-inflammatory effects of Omega 6.
Well, your Omega 6 levels are getting slashed on a carnivore diet. That hallowed 1:1 ratio is going to be a whole lot easier to maintain.
Meanwhile, Omega 3 is a polyunsaturated fat with unstable double bonds, and it’s even more prone to oxidation than the evil Omega 6.
Fish oil capsules are highly processed and will likely be rancid on arrival. You might think you’re doing your body a world of good when you’re slamming a dozen organic fish oil capsules, but in reality you’re subjecting your body to an oxidative storm.
Summary – It would be a good idea to eat fatty fish or eggs once or twice a week, but the requirements are going to be lower thanks to the lack of Omega 6 on carnivore. Avoid inflammatory fish oil capsules.
Magnesium
This key electrolyte is the spark plug that’s needed for over 600 cellular reactions that are needed to bodily processes, such as muscle contractions, nerve function, and energy production.
The daily requirement is around 400 mg for men and 310 mg for women. Steak provides 22 mg per 100 g serving. So eating 3lbs in a day would get you around 300 mg.
This might feel like it drops a little short, but it once again needs to be pointed out that the RDIs are purely designed with high carb diets in mind, and that will add some confounders that add considerable bulk to the requirements.
Sugar, for example, increases the excretion of magnesium by the kidneys. Oxalates and phytates are antinutrients commonly found in plant foods, and reduce the absorption of magnesium. There’s a reason why 50-80% of people are deficient in magnesium. The western diet is potent at stopping us from getting to it.
An intake of 200-300 mg of magnesium from red meat should be more than enough to meet your actual requirements. But if you still want to stack up, bacon has 33 mg per 100g, and bone broth has 17 mg in a single cup.
Summary – Any carnivore diet will have plenty of magnesium, although it can still be useful to supplement with a good electrolyte powder during high intensity exercise.
Folate
Also known as Vitamin B9, folate is crucial for basic cell function and cell growth, while also being involved in the production of red blood cells, DNA, and babies.The daily requirements have been penciled in at 400 mcg.
Plant foods like spinach, chickpeas, lentils, and soy are often touted as great sources of folate. Animal foods are more sparse. Lamb has 24 mcg per 100g, while beef has 7 mcg. So 1kg of beef only gets you 70 mcg, which is well short of the requirements.
Beef liver does have a far superior 253 mcg per 100g, but there are issues with getting in that much liver, and the concentrated nutrients it provides, on a daily basis. I’ll be getting to that soon, but I don’t want to take the discussion of folate off the rails.
Eggs contain a respectable 47 mcg per 100g, which is just one of many reasons to get more of nature’s own multivitamin.
If you’re still concerned about folate, then chicken liver is a better alternative to beef liver due to having double the amount of folate, along with lower Vitamin A, copper, a better balance of fat-soluble vitamins, as well as a decent amount of Vitamin C.
Summary – Meat will contain some folate, but it wouldn’t be a bad idea to add in eggs to tally up.
Vitamin A
Also known as retinol, Vitamin A is fat-soluble, and is important for vision, the immune system, and reproduction. Most nutrient calculators list muscle meat as being devoid of Vitamin A, which is why many look to liver or liver supplements for a concentrated source.
But the fact remains that animals store the fat-soluble vitamins in their fat stores. So just like dairy is a fantastic source of Vitamin A, so does any meat that has a decent amount of fat.
The same goes for Vitamin K2, and Vitamin D3, which these sites seem hesitant to add. Otherwise eggs have 160 mcg per 100g serving, which is 18% of the daily requirements.
Summary – Fatty animal foods will all contain a decent amount of Vitamin A, and once again it would be the smart play to throw in a few eggs to top up. Liver is often advertised for its Vitamin A content, but there is the issue of toxicity from getting too high of a dose.
Calcium
A critical electrolyte that’s needed for bone growth, muscle contractions, and blood clotting. The requirements have been set at 700 mg a day, and beef falls short with only 6 mg per 100g.
It’s worth adding that your calcium requirements will likely be lower on the diet, since you’re free of the antinutrients like oxalates that normally bind and block calcium, while high protein intakes have been shown to significantly increase absorption.
Calcium won’t be a problem if you can indulge in dairy, with cheese containing 721 mg per 100g, comfortably clearing the requirements. But not everyone can get away with eating dairy on carnivore due to its various digestive issues. Which once again leaves you with eggs, with a very respectable 129 mg per 100g.
Summary – Meat is low in calcium, so it’s worth adding in eggs, bone broth, or whatever dairy you can get away with.
Iodine
This mineral is involved in fertility as well as the production of thyroid hormones. An iodine deficiency is the most common cause of hypothyroidism, which basically means you get cold, fat, and lazy.
The daily requirement for iodine is 150 mcg. Beef has around 10 mcg per 100 g, which gets you pretty much over the line. But the issue here is that the RDI for iodine was extrapolated from a study on cattle, and was designed to find the minimum amount needed to prevent goiters.
This is by no means optimal for humans, and that’s inconvenienced further by the fact the soils are depleted of iodine. Other minerals like bromide, chloride, and fluoride are also pervasive in the environment and block iodine from being absorbed. Given iodine’s critical role in thyroid metabolism, and the factors inhibiting iodine uptake, it’s worth pumping the RDI numbers.
The Japanese are eating 13 mg of iodine per day, and boasting some of the healthiest people in the world. Could there be a connection?
Iodised salt has 40 mcg per g.
Salmon has 63 mcg per 100 g.
Eggs have 50 mcg per 100 g.
Mackerel has 143 mcg per 100 g.
This is a good part of why I think mackerel is neglected when talking about superfoods. Not exactly short on Omega 3 either.
Summary – The RDI of iodine is below optimal levels, and you’re best off sourcing more iodine-rich foods than beef. This may even be a cause for supplementation. Yes, our ancestors wouldn’t have done it. But our ancestors didn’t have to contend with depleted soils.
Should You Eat Liver?
Given that liver is the most nutrient dense food on the planet, and contains many of the nutrients that muscle meat has questionable amounts of, it may seem practical to just add in 100 grams of beef liver to cover your bases.
100 grams of beef liver gets you:
Folate – 253 mcg
Vitamin C – 25 mg
Vitamin A – 4968 mg
Copper – 9.8 mg
But as I’ve alluded to before, liver needs to be dosed with caution. Because while too little of a nutrient is a problem, you can also receive grief from having too much of that nutrient.
Vitamin A and copper toxicity being two classic examples of excessively dosed nutrients that often stunts carnivore dieters that indulge too liberally in liver.
Anything above 2oz of beef liver will exceed the tolerable upper limit for Vitamin A consumption, which can lead to a host of unsavoury side effects, like hypothyroidism. The very thing that carnivore critics label as a consequence of excess ketosis.
High levels of copper can raise estrogen, while depleting zinc, iron, and Vitamin C.
Our ancestors would have eaten liver, but they wouldn’t have had as much of it as some people are recommending. A cow’s liver to muscle meat ratio is 1:100. If you’re eating 100 grams of liver a day, then you’d also need to plough through 10 kg of meat to stay noble under the gaze of your paleolithic forefathers.
If you’re eating 1500 grams of meat a day, then 15 grams of liver would fit in your ancestral ratios. If you’re going to have extra, try rolling with chicken liver instead due to their lower Vitamin A and copper levels.
I still wouldn’t label liver as a necessity, but it can be useful for the opening stages of a carnivore diet as you’re attempting to plug the many deficiencies that you’ve carved out on the nutritionally-bereft standard western diet.
Wrapping Up – Should You Ignore The RDIs?
It should be clear at this point that the daily requirements of essential nutrients are built to accommodate a high carb diet that can severely blunt the absorption and utilization of said nutrients.
But that doesn’t mean you should discount them entirely and simply go for red meat and vibes. You can, and some long-term carnivores have appeared to have done just that, without showing any ill effects. But the safe option would be to diversify your animal portfolio to get a better spread of nutrients.
Fatty red meat will do the heavy lifting, and should get the largest share of your intake. Eggs, dairy, pork, organ meats, and fatty fish each have their respective advantages and can be considered as long as you tolerate them.
If nothing else, you’re also improving the palette, and adding that little bit of spice that can go missing when you’re eating nothing but salted ground beef every day.
I’ve been there.
This is the carnivore version of eating the rainbow. Except, unlike the conventional dietary rainbow, this one actually delivers.
Nice post! Are most fish oils still inflammatory? I was under the impression I should take more omega 3nto combat the higher levels of omega 6 but I’m not sure now
Fish oils are virtually all going to be inflammatory, and I don’t think they’re worth the trouble and money in sourcing the cold pressed ones. If you’re not eating seed oils, nuts, and seeds, then that’s going to do far more for you than slamming fish oils.
Fantastic research and post!
Thank you!
I found your site reading about cholesterol….. and kept reading…. great stuff….. I’d like to know more about triglycerides and also liver function…. I’m 62 female active and have been eating (mostly) grass fed red meat/goat kefir/ cram in coffee/ raw honey and fruit….. some organic basmati rice as well and EGGS…….
Thank you for checking out my blog! And I don’t think there’s anything wrong with adding your own sprinkle to the carnivore diet, especially if it comes after you already take your time to go through the initial beef and salt detox phase.
Salt detox?
Why would you need a salt detox?
First of all, amazing information you have here!! Thank you for sharing it! Also, I wanted to ask you about Manganese, no one ever talks about it when they discuss nutritional deficiencies in the carnivore diet, but as I understand meat is very low in manganese, am I wrong? Is it unimportant?
Manganese is pretty important for glucose metabolism, so carnivore will naturally need less. Liver and dairy contain enough manganese, and chances are, so will your drinking water.