Bioavailability, most overlooked concept in nutrition

5 Mins read

What is Bioavailability?

Bioavailability in simple terms is the measure of how well the nutrients from food or supplements are absorbed and utilized by your body. Bioavailability shapes the quality of nutrition you get from your food and supplements

When you acquire nutrients through food and supplements, there are primarily two things to consider namely the ”nutrient quantity” and “nutrient quality”.

Nutrient quantity refers to the amount of certain nutrient in grams, milligrams or micrograms present in some food. For example: 18g of protein in 1 cup cooked lentils or 19g of protein in 3 ounce chicken breast.

Nutrient quality refers to how well that nutrient is absorbed and utilized in the body. On paper it seems that lentils and chicken breast contain same amount of protein. But in reality protein in chicken breast is much better absorbed and utilized by the body in comparison to lentils.

Hence, this makes chicken a better source of protein than lentils.

When the nutrient quality of some food is good we say that nutrients in that food are more bioavailable and when the nutrient quality is poor we say that the nutrients are less bioavailable. In the above example chicken has more bioavailable protein as compared to lentils.

In a food or supplement the more bioavailable nutrients are better the quality of them.

What is the Importance of bioavailability?

Bioavailability is important because without it you cannot determine if the diet you eat is nutrient dense or not. Like, if you ignore the bioavailability of foods in your diet you will end up in a situation where you think that you eat a healthy nutrient dense diet but actually you don’t.

Let’s take carrots and butter for example. Both of them are a great source of vitamin A. But, carrots have a form of it which is not very well absorbed. Butter on the other hand has a form of vitamin A which is far better absorbed and utilized by the body.

So, in this case butter has more bioavailable vitamin A in comparison to carrots. This makes it a better vitamin A source.

Now, if you do not consider the bioavailability factor you will add carrots in your diet in a hope to increase your vitamin A intake but actually you won’t get enough of it as you will get from butter.

See why bioavailability is important? It defines the quality of your diet and the nutrients you are getting from your food.

People often overlook this concept and base their diet around wrong kind of foods assuming that they eat healthy nutritious diet where in reality they don’t.

Always remember, the higher the bioavailability of nutrients, the better the quality of food.

Now that we have understood how and why bioavailability plays an important role in our diet let’s take a look at bioavailability of foods.

Bioavailability of foods

There’s one simple formula we need you to know when it comes to bioavailability of foods. That foods of animal origin are always more nutrient dense than foods of plant origin.

Many believe that milk, meat, eggs and seafood contain just calories and protein but in reality they are the source of highly bioavailable nutrients. Those foods are even more nutritious than fruits, vegetables, whole grains, cereals, beans and legumes combined.

This is not to say that plant based foods are not nutritious. Those foods do contain vitamins and minerals and are actually healthy. But in essence, nutrients found in animal based foods are significantly more absorbable and utilizable by the body in comparison to plant foods.

Protein, fats, vitamins and minerals in animal foods are all highly bioavailable. That means, they are present in a form which is easily absorbed and utilized by the body.

Protein: High quality protein is obtained only from animal flesh, organs, milk, cheese, eggs and poultry. Plant based sources like lentils, chickpeas, beans, soy, tofu contain poor quality protein.

Fats: Anti-inflammatory and brain boosting omega 3 fats, EPA, DHA are found in good quality fish and seafood and are totally absent in plants.

Vitamin A: More bioavailable from foods like butter, lard, tallow, egg yolks, red meat, cream, whole milk, cheese. Plant foods like carrots, sweet potato, pumpkin contain pro vitamin A which is far less absorbed and utilized in the body.

Vitamin D: More bioavailable in animal fats, fatty fish, butter, cheese and good quality milk. Less bioavailable in mushrooms.

Vitamin K: More bioavailable in foods like liver, dairy, cheese, chicken, red meat, egg yolks, fermented vegetables. Less bioavailable in plant foods like green leafy vegetables.

B vitamins: Vitamin B12 only found in diary, eggs, meat and seafood. Other B vitamins like B9, B6, B5, B1, B2 and B3 all are found in ample amounts in those foods.

Zinc: highly bioavailable in red meat, oysters, pork, crabs, shrimp, poultry, cheese, chicken. Far less bioavailable from grains, nuts, seeds, oats, lentils.

Iron: Meat contains heme iron which is the most absorbable form of it. Plant based iron from green leafy vegetables and other sources is far less absorbed and requires vitamin C for absorption.

Calcium: Present in dairy, seafood and green leafy vegetables, beans, and tofu. However, Calcium is best absorbed from milk and seafood than from green leafy vegetables and other plant based sources.

Other minerals: Meat, milk, seafood and poultry are great sources of other highly bioavailable minerals like copper, phosphorus, selenium, iodine, potassium, magnesium, chromium all of which are poorly 2absorbed from plant based foods.

Enzymes: Raw animal foods like raw milk, raw fats, raw egg yolks, raw meat, raw fish contains high quantities of enzymes which makes them easy to digest and provide many other health benefits to the body. Raw plant foods on the other hand are very hard on the gut because they contain something called anti nutrients and less enzymes.

Even when it comes to quantity of all these nutrients, animal foods offer more nutrients per calorie than plant foods. This means that animal foods provide more nutrition in less calories as opposed to plant foods which you have to eat more of to get the same amount of nutrition.

Bioavailability of supplements

Even when it comes to supplements bioavailability is crucial. Most of the supplements in the market are just there for making money out of you and do little to nothing in providing benefits they claim to provide. Even many doctors and nutritionists prescribe poorly absorbable form of nutritional supplements to their clients.

We recommend you to do your own research before buying a nutritional supplement. Find out which ones are better absorbed by the body, actually provide benefits and fix nutritional deficiencies.


Our takeaway is that before incorporating any kind of healthy diet, food or supplement in your routine, Ask yourself this question? Does this diet, food, or supplement which appears healthy provides me high quality nutrients which are absorbable by my body? If the answer comes no then it’s of little to no use.

However, if you find, that diet, food or supplement provides you with high quality nutrients then sure include it.

Keep in mind Bioavailability is the basis of nutrition. Poor bioavailability results in inadequate intake of nutrients resulting in poor health. However, when the nutrients are highly bioavailable it provides adequate amount of material to build a strong healthy body.



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About author
Hey, I am Chetan and i am the author of “The Primitive diets” I hold a degree in Nutrition sciences and create content around health and nutrition. My principles are centered around primitive and holistic values which have been used since hundreds and thousands of years to treat diseases and improve health.
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