Bioavailability : Explained
understand how our bodies absorb nutrients
Are you absorbing all the nutrients from the supplements that you are taking? After you’ve taken your daily supplements you would like to think that your body is using every capsule or pill that you’ve consumed right? How your body absorbs the nutrients is just as important as how much you take. We include varieties of dark leafy vegetables, protein from different sources and even seek out how and where they are grown because we are sourcing the best foods for our bodies. The purpose of feeding your body the vitamins and minerals that your health requires is to aid in your daily function, improve how you feel mentally and physically, not just to feel good for the day but to take care of your body for the long ride. But if your body is not absorbing all the important vitamins and minerals you might as well eat mcdonalds and frozen pizza just to stay full.
What is bioavailability?
Simplified version: bioavailability is how much of a substance is able to be absorbed into your body through your intestines, then the useful nutrients are then absorbed into your bloodstream and are either used by your cells or stored. Let’s keep in mind that our bodies are not made perfect so not all the nutrients are absorbed, some are destroyed in our digestive system and some just pass through our bodies and are excreted. When you consume nutrients, only some of that nutrient is available to your body and the rest are stored or passes through us, bioavailability is the measurement of how much gets absorbed by our bodies and how much we get out.
Why is it important
Why is nutrient absorption important? Our survival depends on it! That’s why we have an organ specifically dedicated to doing that one job- our gastrointestinal system. If our bodies cannot absorb the nutrients from our food it is not good for your muscles, brain, cells and your health overall.
Highly bioavailable macronutrients (Macronutrients are those nutrients that the body needs in large amounts.) are carbs, proteins and fats, these provide our body with energy (calories). However the essential micronutrients (nutrients that the body needs in smaller amounts such as vitamins, minerals) can be harder for our bodies to absorb.
How are nutrients absorbed by the body?
- Chewing and the introduction of enzymes in your mouth
- Swirling and mixing with your stomach acid (gastric juice) in your stomach
- Nutrients get absorbed in your small intestine—(nutrient absorption headquarters!)
- Nutrients enters into the bloodstream -Carrier proteins bring the nutrients into your cells
Digestion pretty much starts from the first bite. The chewing action is breaking down the food for absorption, to further that breakdown, your mouth produces enzymes in your saliva called salivary amylase to assist in the process.
The small intestine: This is the stage where we are most interested in absorption. It removes the vitamins, minerals, fatty acids, amino acids to of the food and delivers it to the cells using tiny lumps called villi.
Hundreds of thousands of microscopic villi cover your small intestine. Villi is made from a unique structure that makes it possible to pull macro and micro nutrients out of your food and bring them to your bloodstream.
The journey doesn't end here, after our body absorbs the nutrients, it then needs to enter our cells to get delivered to the rest of the body.
Factors that affect bioavailability
Bioavailability is influenced by your personal genetic makeup and your food/supplement choice.
Your body’s absorption rate is determined by:
- your overall health, age
- biological gender
- nutrients present in your body.
Other factors that determine the nutrients bioavailability include:
- food/ supplement structure (plant cell wall, mushroom chitin)
- other food/supplement that are ingested at the same time
- how the food is cooked
- quality of your food/supplement
Structure of food
The structure from different plant sources details the digestion rate. For example corn, meat, plants (they have a cell wall), mushrooms (contains chitin that gives strength to the cell wall of the fungi), these factors make it more difficult to break down therefore less bioavailable. These type of foods need to be cooked, broken down or extracted for absorption of certain micronutrients to be possible.
Health and Age
Inevitably, our gastric acid declines as we age, so older individuals will have less bioavailability than younger individuals. As we age and slow down, so does our ability to absorb micronutrients. For those who have underlying health issues such as anemia, it would be more difficult for those individuals to absorb iron then someone of similar age who is not anemic.
Vitamins and minerals can come from different sources, and due to that factor, it’s chemical form can be different. Example Heme iron is more readily available for absorption than non-heme iron. You can find Heme iron in foods such as poultry, meat, or fish and non-heme iron is found in plants. A vegetarian would need to eat more of that plant source to the same amount of iron as a smaller piece of meat.
Different foods that are ingested at the same time
There are antioxidants such as polyphenols and phytates that can prevent micronutrients from being absorbed by the body in the gastrointestinal tract. These antioxidants bind with minerals and prevent them from being absorbed. Phytates can bind with minerals such as calcium, iron and zinc. Phytates is found in the outer layer of plants and polyphenols are a compound found in plants.
Food/supplement quality and formulation
Not all food/supplements are made equal. Nutritional scientists acknowledge the importance of nutrient bioavailability. Significant research for the maximum bioavailability technology is now available in various forms, all of which influence bioavailability. Different methods include changing the particle size, solubility and binding cations to the types of encapsulation ( gel, capsule, tablet)
Time release technology can be found in these forms- delayed release, extended release, sustained release-all maximizing bioavailability. Supplements with these technologies will be reflected in the price. However you will not need to consume as much to receive the same amount of nutrients. In most cases you are saving money and getting a better quality product.
Making healthy food choices and supplementing when you are not getting enough of that particular nutrient is an essential part to living a healthy lifestyle. Educating yourself on ways to ensure that your body receives the maximum bioavailability will reap the full benefits. With different ways to improve your absorption, bioavailability is directly related with the positive effects nutrients have on your health.