Depending upon which areas of the ‘health’ industry you listen to, you’d be lead to believe that we can obtain all the nutrition we need from synthetic vitamins or pre-packed meal replacement drinks. Whilst these companies do a good job of marketing their health claims, the truth is that if you want to build a thriving, strong, healthy, hormonally balanced body, you need to be consuming nutrients in their most bioavailable form. For many nutrients such as iron, zinc and B12, this means consuming them from animal foods. Here, we'll explore the difference between whole plant foods, beef organs and synthetic supplements to discover which is the best choice when it comes to giving your the most nutrients in an easy to absorb form.
What does ‘bioavailability’ mean, and why does it matter?
The term ‘bioavailability’ refers to how much of a food’s nutrients can be absorbed by the body. For example; a food such as 100g spinach may contain around 2.7mg iron, yet we only absorb around 1-2% of the iron, as other ‘anti-nutrient’ plant compounds like oxalates strongly prevent us from being able to access and absorb the iron. 100g of beef liver however, not only contains far more iron at 17.9mg, but it’s also much easier to absorb, giving us at least 20-35% absorbability. This means that animal foods - especially Beef Organs - are a much better choice if you want to make sure you’re absorbing nutrients like iron from them, because essentially; if it doesn't absorb, it doesn’t work.
When it comes to supplements, some types of vitamins and minerals are well absorbed by the body, however the issue is that these vitamins and minerals are often synthetic (essentially ‘fake’) and lab-made, leading to nutrient imbalances and possible overload of certain minerals. That’s why we truly believe the healthiest supplements aren’t made in a lab; they’re made in nature.
What is a multivitamin? And why you might not need one…
A multivitamin is a supplement containing many different vitamins and minerals (like B vitamins, vitamin D, vitamin D, iron, zinc etc) bundled together with the intention to fill nutritional ‘gaps’ in a person’s diet. The idea behind multivitamins emerged in the early 20th century, after scientists identified individual vitamins while studying deficiency diseases like scurvy, rickets, and beriberi. By the 1930s and 1940s, synthetic vitamins became widely available and were soon marketed as a convenient health safeguard.
Sounds great, right? But the thing is, if something seems too good to be true, it probably is. There are many issues with multivitamins, including:
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They give a false sense of nutritional security, meaning you’re less likely to put thought into obtaining nutrients from specific foods if you know you’ve already taken them in pill-form
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Evidence for their benefits in generally healthy people is surprisingly weak, with many large studies finding little to no effect on preventing chronic diseases
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They sometimes provide unnecessary or even excessive doses of certain nutrients in an unbalanced form
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The nutrients within them often compete for absorption, meaning you won’t really be absorbing several of the vitamins and minerals within them
That’s why we believe in a natural, targeted approach to replenishing your nutrient levels. There are many foods found in nature with a wide range of vitamins and minerals such as eggs, beef liver or oily fish that can be considered ‘multivitamins’, and we believe it’s important to get your nutrients from these foods instead of relying on a lab-made synthetic supplement.
What’s the issue with synthetic supplements?
Synthetic supplements can be problematic because they’re not nutritionally balanced in the way whole foods are, often providing isolated nutrients without the natural cofactors like enzymes and associated vitamins and minerals that aid proper use in the body. For example, the mineral copper actually helps us properly use and absorb iron, and without it, we can easily end up with iron stored in the tissues, but not able to be actively used.
Some synthetic forms are also poorly absorbed or utilised, like as magnesium oxide, calcium carbonate, synthetic vitamin E, folic acid, and isolated beta-carotene, which the body doesn’t process efficiently. Common genetic variants like the MTHFR gene mutation (which around 40% of people may have) make it difficult to properly absorb and utilise synthetic folate, making it essential to consume the active form known as methylfolate, found in foods like beef liver in high and beneficial levels. Variations in the BCMO1 gene also significantly reduce the body from efficiently converting beta-carotene into vitamin A, essential for healthy vision, immunity, fertility, skin and gut health. Again, beef liver is an incredible source of this nutrient in a highly bioavailable form.
Whilst we also know there are plenty of clean and high-quality multivitamins out there, the truth is that many synthetic supplements may contain unwanted substances including heavy metals, chemical solvents, artificial dyes, preservatives, or residues from manufacturing, all of which can place extra stress on the liver and other detoxification systems. Again; that’s why we believe the healthiest supplements aren’t made in a lab. They’re made in nature.
What you need to know about plant foods
Some of the most important nutrients for energy production, gut health and hormone health include zinc, iron and vitamin B12. Whilst you may be able to obtain some of these nutrients in small amounts from plant foods, the issue is that you’d either have to consume a huge amount of them to get close to the nutrient levels you need, or the fact that they simply don’t contain enough of the nutrient. Plant foods for example, don’t contain the true active form of B12 known as cobalamin, and instead contain an inactive ‘analog’ of B12 that can actually block true B12 absorption, leading to deficiencies.
If you’re looking to boost iron levels, it’s also important not to be fooled into thinking that plant sources of iron can be truly effective. As we mentioned, foods that are often thought of as being high in iron such as spinach are only 1-2% bioavailable. Other ‘iron rich’ plant sources like lentils are a little easier to absorb, but still contain anti-nutrients like lectins that can block absorption, and it takes dedicated preparation in order to remove some of the anti-nutrients and unlock the vitamins and minerals within them.
Zinc too is often poorly absorbed from plant foods, as it comes in a form known as ‘non heme zinc’. As zinc is so essential for hormone health and fertility, it may be important to consider adding in zinc-rich animal sources such as oysters or beef liver to support your body’s needs.
Comparing synthetic supplements, plants and Beef Organs
At APE Nutrition, we’re not anti-plant foods. We’re just pro nutrient-dense foods, and it so happens that the most nutrient-dense foods on earth are organs like liver, heart and kidney. We’re also pro-knowledge and empowerment, and we want you to understand which foods can help you thrive, and how to make the best choices when it comes to choosing between synthetic supplements, plant sources and Beef Organs.
Here, we’ll outline the difference between the bioavailability of iron, zinc and B12 in plant sources vs Beef Organs, and what to look out for with synthetic supplements, giving you the knowledge and power to make more educated decisions on how to nourish your body.
Let’s break it down…
Iron
Bioavailability of iron from spinach: 1-2%.
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High oxalate levels strongly inhibit absorption
Bioavailability of iron from lentils: 5-10%.
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Phytates inhibit absorption, and dedicated preparation methods such as soaking and fermenting are required to remove these.
Bioavailability of iron from almonds: 2-6%
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Phytates and polyphenols reduce absorption
Bioavailability of iron from beef liver: 20-35%
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Absorption increases if the body is iron deficient and needs extra amounts
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Vitamin A in liver may further support iron metabolism
Iron from synthetic supplements
Only 10-20% of iron from synthetic supplements is absorbed at once. The rest stays in the gut and can alter gut motility, feed bacteria leading to gut dysbiosis, and also commonly triggers bloating, constipation and nausea.
The common side effect of nausea associated with synthetic iron supplementation is often caused by iron supplements dissolving in the stomach and releasing ‘free iron ions’, which are chemically reactive, promote oxidative stress and damage gastric mucosa, potentially damaging the gut lining & leading to issues like ‘leaky gut’…
Look out for these commonly prescribed iron supplements, which are known to have the side effects we mentioned above:
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Ferrous sulphate (very commonly prescribed in pregnancy)
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Ferrous fumarate
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Ferrous gluconate
Zinc
Zinc from plant foods is also known as ‘non heme zinc’ and isn’t as well absorbed as animal sources (which are around 40-60% bioavailable). Considering how important zinc is for hormone health, it’s important to make sure you’re getting plenty of well absorbed zinc.
Bioavailability of zinc from spinach: 10-20%
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Anti-nutrients like oxalates block absorption
Bioavailability zinc from lentils: 15-30%
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Phytates inhibit absorption, and dedicated preparation methods such as soaking and fermenting are required to remove these.
Bioavailability of zinc from almonds: 15-25%
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Phytates block absorption, and soaking or sprouting is required in order to access most of the nutrients
Bioavailability of zinc from beef liver: 40-60%
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The high protein content of liver enhances zinc uptake
Zinc from synthetic supplements
Zinc supplementation can prove very effective when it comes to supporting immunity and even testosterone levels. BUT supplementing with synthetic zinc over long periods of time depletes levels of copper within the body, affecting the nervous system, and potentially leading to anemia. Zinc found in organ meats is naturally balanced with copper, iron and other minerals that help the body absorb it in a balanced way.
B12
Plant foods do not contain true B12. Instead, they contain ‘analogs’. As we mentioned, B12 analogs are molecules that are structurally similar to vitamin B12 (cobalamin) but are often inactive in humans, meaning our bodies can't use them for essential functions like DNA synthesis, and they can even block real B12 absorption. This means if you’re trying to get your B12 from plant sources, you could be doing more harm than good, and fortified foods tend to be the only ones that contain cobalamin.
Animal products like beef, chicken, fish and eggs are rich in true B12, and beef liver is extremely rich in the active form of B12 known as cobalamin, being one of the highest B12 foods on the planet. Importantly, the B12 found in animal foods works synergistically with other nutrients known as ‘co-factors’ like folate (B9), B6 and iron that are needed in order for B12 to be most effective.
Bioavailability of B12 from beef liver: 50-60%
B12 From Synthetic Supplements
Supplementing with synthetic B12 provides the body only with isolated B12, and none of the key co-factors. Cheaper B12 supplements are also often made with cyanocobalamin, which is the cheapest, whereas beef organs like liver contain the activated forms methylcobalamin and adenosylcobalamin.
Key takeaways
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Bioavailability matters more than nutrient numbers
It’s not just how much of a nutrient a food contains, but how much your body can actually absorb and use. Animal foods—especially beef organs like liver—provide nutrients in far more bioavailable forms than plant foods or synthetic supplements.
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Synthetic supplements and multivitamins have significant limitations
Multivitamins can give a false sense of security, often lack strong evidence of benefit for healthy people, and may deliver nutrients in unbalanced or competing forms that reduce absorption or cause overloads.
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Whole foods provide nutrients with essential cofactors
Nutrients in animal foods come naturally packaged with cofactors (like copper, folate, B6, and enzymes) that help the body absorb and utilize them properly—something isolated synthetic supplements often lack.
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Key nutrients (iron, zinc, B12) are poorly absorbed from plant foods
Plant sources contain anti-nutrients (oxalates, phytates, lectins) that inhibit absorption, and some nutrients—like true vitamin B12—are not present at all in plants. Beef organs provide these nutrients in highly absorbable, active forms.
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Beef organs act as nature’s “multivitamin”
Foods like beef liver are among the most nutrient-dense foods on earth, offering iron, zinc, B12, vitamin A, and more in balanced, bioavailable forms—making them a more effective and natural alternative to synthetic supplements.
Nature provides the body with what it needs in perfectly balanced doses, all we have to do is give it what it needs. We hope this gives you an insight into how to make more informed choices about your health and nutrition, and to truly nourish your body.
-The APE Nutrition Team