WHY DOES ABSORPTION AND BIOAVAILABILITY MATTER?

We all know that vitamins and minerals are essential for our health. They fuel key biochemical processes, support immune function, help our bodies repair, and the list goes on and on. But did you know that we actually can’t produce most of them on our own? Here is a list of some of the different types of essential vitamins and minerals that we need to consume through our diet: 

• Water-soluble vitamins such as the B vitamins (B1, B2, B3, B5, B6, B7, B9, and B12) and vitamin C1,2 
• Fat-soluble vitamins such as vitamin A, E, and K (vitamin D is an exception that can be synthesized in our skin with sunlight).1,2,3
• Macrominerals (often required in large amounts) such as calcium, phosphorus, potassium, sodium and magnesium.1,2,4
• Microminerals (often required in small amounts) such as iron, zinc, iodine, selenium, copper, manganese, molybdenum, and cobalt.1,2,4

However, there’s more to the story. Simply consuming nutrients — whether it be through food and/or supplements — does not guarantee that our bodies will absorb them effectively.5,6,7 Nutrient absorption is a complex process influenced by multiple factors, from your own individual health profile to the exact form (food, pill, powder, liquid, etc.) that a given nutrient is delivered in.8 Only after absorption can nutrients begin working their magic. Put simply, absorption matters more than consumption. Let’s dive into how our bodies process nutrients — and why bioavailability is the key to making the most of what we consume each and every day. 

THE JOURNEY OF NUTRIENTS: BIOACCESSIBLE VS. BIOAVAILABLE

From the moment we take a bite of food or a sip of a supplement, the process of digestion and nutrient absorption begins. Enzymes in our saliva start breaking down food, a process that continues throughout the gastrointestinal (GI) tract.8 In particular, the real action happens in the small intestine, where most of our nutrients are actually absorbed into our bloodstream.9 However, there is a key distinction in this process that most people aren’t aware of; that is, the difference between bioaccessibility and bioavailability: 

• Bioaccessibility in its simplest sense is what’s “ready to be absorbed”. It is the proportion of a given nutrient that’s made “accessible” for absorption and eventual use in our bodies. In the context of eating food or taking a supplement, it is how much of a vitamin or mineral is freed to be absorbed in the gut. If a nutrient isn’t bioaccessible then your body won’t even get the chance to absorb it. 
• Bioavailability in its simplest sense is what's "actually absorbed and used". It is the proportion of a given nutrient that's made "available" to your bloodstream and can only be used by your cells. Even if something is bioaccessible, it might not be bioavailable due to other barriers such as poor absorption (some nutrients struggle to cross the intestinal lining), nutrient interactions (some compounds compete for absorption), metabolic processing (some nutrients require chemical modifications before they can be utilized), and health conditions (factors like gut health, age, and diseases).

HOW DO WE INCREASE OUR ABSORPTION OF NUTRIENTS?

The science of measuring bioavailability is a complex process. Everything from the time of day a supplement is taken to an individual’s metabolic rate can affect absorption.6,7,9,11 Scientists use both in vitro (lab-based) and in vivo (human or animal-based) studies to understand how nutrients are absorbed and metabolized.7,11 While in vitro studies simulate digestion in a controlled environment, in vivo studies provide real-world insights. By using both methods, researchers can gain a comprehensive picture of a nutrient’s bioavailability.

The sad and surprising truth is that most traditional supplements don’t fully absorb. So, how much of traditional supplements do we actually absorb? To better answer this, we sought out scientific studies and results that measured bioavailability from traditional dietary supplements. The nutrients that we managed to find information on paint a sad picture, that the bioavailability of many supplements is extremely low. If we assume this is a representative sample, on average, only 15% of a supplement’s active ingredients are actually absorbed and used by the body. That means 85% of what’s in the supplement could pass through your system without ever being utilized!

Table 1 – Bioavailability of Common Nutrients5,12,13

This highlights a major challenge in the supplement industry: ensuring ingredients are formulated in ways that maximize absorption. Without optimized delivery systems, even the best ingredients may not be able to provide the benefits that they promise. Unfortunately, the current status quo doesn’t incentivize this and hence, it’s no surprise that most supplement companies opt for simpler and cheaper delivery formats with lower bioavailability such as pills and powders. 

We believe that the future of supplements lies in advanced nutrient delivery methods that maximize bioavailability. By prioritizing bioavailability, we can ensure that the nutrients that we consume don’t just pass through our bodies — but truly nourish, restore, and support our long-term health. We are committed to driving this initiative forward within the supplement industry and hope for you to join us along the way. 

SOURCES

1. Godswill, A., Somtochukwu, I., Ikechukwu, A., & Kate, E. (2020). Health Benefits of Micronutrients (Vitamins and Minerals) and their Associated Deficiency Diseases: A Systematic Review. International Journal of Food Sciences. https://doi.org/10.47604/ijf.1024
2. Tahir, N., Alkubaisi, M., Elias, N., & Al-Auqbi, T. (2024). Reflection of Vitamins and Mineral Deficiency in General Health Condition: Article Review. Journal for Research in Applied Sciences and Biotechnology. https://doi.org/10.55544/jrasb.2.6.27
3. Ekong, M., Nwakanma, A., & Iniodu, C. (2024). Exploring micronutrient supplements in disease conditions: are they effective?. Journal of Food, Nutrition and Diet Science. https://doi.org/10.55976/fnds.2202412051-17
4. Bielik, V., & Kolisek, M. (2021). Bioaccessibility and Bioavailability of Minerals in Relation to a Healthy Gut Microbiome. International Journal of Molecular Sciences, 22. https://doi.org/10.3390/ijms22136803
5. Brandon, E. F., Bakker, M. I., Kramer, E., Bouwmeester, H., Zuidema, T., & Alewijn, M. (2014). Bioaccessibility of vitamin A, vitamin C, and folic acid from dietary supplements, fortified food, and infant formula. International Journal of Food Sciences and Nutrition, 65(4), 426–435. https://doi.org/10.3109/09637486.2013.869795
6. Nicolescu, A., et al. (2023). Bioaccessibility and bioactive potential of different phytochemical classes from nutraceuticals and functional foods. Frontiers in Nutrition, 10, 1184535. https://doi.org/10.3389/fnut.2023.1184535
7. Etcheverry, P., et al. (2012). Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B6, B12, D, and E. Frontiers in Physiology, 3, 317. https://doi.org/10.3389/fphys.2012.00317
8. Patricia, J. J., & Dhamoon, A. S. (2022). Physiology, digestion. StatPearls. Treasure Island, FL: StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK544242/
9. Andrés, A., & Heredia, A. (2021). Advanced research in food digestion. Foods, 10(1), 122–124. https://doi.org/10.3390/foods10010122
10. Rodrigues, D. B., et al. (2022). Trust your gut: Bioavailability and bioaccessibility of dietary compounds. Current Research in Food Science, 5, 228–233. https://doi.org/10.1016/j.crfs.2022.01.002
11. Sensoy, I. (2021). A review on the food digestion in the digestive tract and the used in vitro models. Current Research in Food Science, 4, 308–319. https://doi.org/10.1016/j.crfs.2021.04.004
12. Devi, S., et al. (2020). Measuring vitamin B-12 bioavailability with [13C]-cyanocobalamin in humans. American Journal of Clinical Nutrition, 112(6), 1504–1515. https://doi.org/10.1093/ajcn/nqaa221
13. Firoz, M., & Graber, M. (2001). Bioavailability of US commercial magnesium preparations. Magnesium Research, 14(4), 257–262. https://www.researchgate.net/publication/11563416_Bioavallability_of_US_commercial_magnesium_preparations