A healthy lifestyle requires good nutrition. According to current population studies, the modern diet fails to provide enough of the vital essential nutrients and vitamins we need. The results from which may lead to long-term health problems.
Supplementation is a way of providing additional nutritional support to meet our body's needs. As consumer demand for supplementation increases, so is the interest in learning more about which nutritional forms and delivery systems offer the best bio-therapeutic results. Never have we witnessed a time, due to the rise in mobile internet use, when consumers are now the driving force behind nutrition evolution.
In this article, we discover the many reasons behind what can affect the absorption and bio-availability of nutrients from our food and supplements. Consumers are now more aware than ever that just because a supplement claims to contain a particular amount of a specific nutrient does not mean their body will absorb or utilise it effectively. Welcome to the rising demand for high absorption and bio-available supplements.
What is Nutrient Bioavailability
Bioavailability is the quantity of a given nutrient in food, drugs, and supplements that is absorbed primarily in the intestines and eventually available for biological action in your cells and tissues.
Bioavailability can be hampered by a variety of reasons that can vary greatly from person to person. Even if two people ingest the same nutrients in the same form, their bodies may absorb and utilise the nutrients in different ways. Here are some of the reasons why:
Medications - Certain prescription medications can affect the absorption and bioavailability of some supplements. For example acid-reducing medicines, , might affect vitamin B12 absorption, and antibiotics can kill "good bacteria" in the digestive tract that would otherwise help with vitamin and mineral digestion and absorption. (r1)
Digestive disorders - Crohn's illness, irritable bowel syndrome (IBS), chronic heartburn, and celiac disease compromise the body's ability to absorb and utilise nutrients appropriately. (r2-r3)
Alcohol - Alcohol can have a detrimental impact on nutritional absorption. It helps pills and capsules break down quickly before they reach the small intestine, where they are absorbed. Alcohol also affects the stomach and small intestinal lining, limiting vitamin and mineral absorption. (r4)
Caffeine - Caffeine, similarly to alcohol, inhibits nutritional absorption and encourages the excretion of important vitamins and minerals. It includes tannins (a type of plant chemical) that, when ingested in large amounts, can prevent calcium, iron, magnesium, and B-vitamin absorption. Research also demonstrated that the great the caffeine intake, the more inteference it had in reducing the expression of vitamin D receptors on osteoblasts in the body – the cells responsible for producing bone, thus affecting absorption. (r5- r7)
Stress - Constant stress can impact your body, placing it into a low-grade adrenal "fight-or-flight" state that wreaks havoc on your digestive system, resulting in indigestion or heartburn. This can wreak havoc on your digestive system and deplete your body's nutrient supplies. (r8)
Age - With age, the stomach lining becomes less active, and inflammation of the stomach lining can result in reduced production of stomach acid (hypochlorhydria) or even a complete lack of acid production (achlorhydria), affecting the body's ability to absorb nutrients. (r9)
What is the difference between Bioavailability & Absorption?
The two terms bioavailability and absorption are often used to describe the same mechanism, when there are in fact key differences between them.
Essentially, absorption is the uptake of nutrients from the gastrointestinal tract into the blood (Plasma). In order to be absorbed, certain nutrients need to be broken down (digested) into smaller nutrients, for example, proteins into amino acids, starch into glucose and fats into fatty acids. Once arrived in the small intestine they are then absorbed by a variety of transporter channels, specific to each nutrient, into the blood.
Bioavailability is the percentage of the dose of a nutrient or other substance that is absorbed into the bloodstream and its availability (in its most unchanged form), which can be actively used by the body.
By way of an example comparison
Nutrient (A) is given intravenously – This removes the need for intestinal absorption and first-pass metabolism*. It is delivered straight into the blood. By definition, when a nutrient is administered intravenously, its bioavailability is 100%.
On the other hand, following oral administration, nutrient (B) might be 90% absorbed but 40 % bioavailable, while nutrient (C) might be 80 % absorbed and 60 % bioavailable.
Effective Nutrient absorption is critical to determine whether or not the nutrient produces the desired bio-therapeutic effect. How quickly it is absorbed and how long it stays intact within the body, relates to its time-to-peak concentration (Tmax) and bioavailability (Fractional) effect. It is possible for nutrients to be well absorbed but then they may be quickly broken down, i.e. by the ‘first pass metabolism’ i.e. in the liver and stored or disposed of before they even reach the target destination. Some ways to overcome poor bioavailability, we can increase the amount of a nutrient (not always effective), change the way it is delivered into the body or change the nutrient into a different form i.e. by adding organic or inorganic molecules as carriers to enhance absorption.
Four most prominent ways nutrients enter your bloodstream:
- Mucous membranes of the mouth.
- Wall lining of the upper intestine.
- Wall lining of the colon (via suppository)
Primarily, orally consumed food and supplements deliver nutrients to the bloodstream via the upper, small intestine.
Here's when problems can arise…
The digestive system is a complex, interconnected organ network that breaks down food into nutrients from the stomach to the intestine. When you eat, your body secretes hydrochloric acid and various digestive enzymes that break down food into smaller molecules that the small intestine can absorb. The problem is that during this process, the stomach can damage or destroy certain nutrients, which can result in mineral deficiencies leading to chronic health issues
Ingredients like L-Glutathione, Alpha Lipoic Acid, CoQ10 and SAMe are not easily digested and absorbed by the body on their own.
To overcome these and many of the other absorption and bioavailability hindrances mentioned earlier, special delivery systems and ready-active nutrient forms can provide better results and value for money (and let us not forget the most crucial aspect…improved health!)
Poorly absorbed nutrients by the body
Depending on the nutrient, and where and how it is released in the body will determine its overall beneficial effect. Here are some examples:
The amount of L-Glutathione we consume in food is not very high to provide an impact on the levels within our blood. This is because the Glutathione is a fragile molecule, easily damaged by stomach acid. The body therefore relies on the liver to produce Glutathione, which is ok when we are younger, but as we age our body produces less of it. Consuming encapsulated liposomal Glutathione protects the Glutathione molecule from being damaged or dismantled in the stomach, allowing for greater absorption in the intestines.
Scientists discovered that encapsulating Glutathione with tiny bubble-like structures, called Liposomes, protects it from being dismantled by the gut, so more is absorbed into our body (r10). Once absorbed into our body the liposomes then target delivers the Glutathione into our cells.
It is suggested that consuming up to a 200mg dose of conventional oral form Vitamin C can achieve 70 - 90% absorption. Beyond this level, the body regulates absorption through the small intestine SCVT1 receptors, which may reduce intake to just 15 - 30%, with the remaining excess passed via the urine. (r11)
Liposomal Vitamin C bypasses the normal absorption channel through slow vitamin C receptors type 1 (sodium-dependent vitamin C receptors SCVT 1). Instead it is absorbed via the lymph achieving much higher absorption compared to standard Vitamin C supplements.
Slow time-release methods or Liposomal encapsulated Vitamin C nutrients, better protected against the damaging effects of stomach acids, can help increased Vitamin C levels within the blood (Plasma).
Vitamin B12 (commonly known as cobalamin) is one of the largest and most complex vitamins. To absorb vitamin B12 into the body, it has to undergo several processes. B12 is first separated from food by stomach acid. It then binds to another protein to be escorted into the small intestine. From the small intestine, it attaches to the ‘Intrinsic Factor’ protein transport molecule. The complex is absorbed into the body, releasing Vitamin B12 into the blood.
Studies suggest that anything in the stomach that affects the normal acidity and digestive processes, ranging from infections to acid reflux to medicine to ageing, may interfere with B12 absorption. (r12) For example as you age, you normally suffer with lower stomach acid.
Magnesium is an essential mineral that we need for various bodily functions, including muscle and nerve function. Although it's not a vitamin, many people consider magnesium to be one because the body cannot produce it and it must be obtained externally. It can also help prevent or treat symptoms of depression, anxiety, insomnia, diabetes type 2, high blood pressure and others. However, there are some challenges with getting enough magnesium from diet alone - especially if you have a gluten allergy or celiac disease which make absorption difficult.
Another reason that we might experience poor magnesium absorption, is when it might have to compete with other minerals using the same transporting channels into the blood (r13-r14). Using Chelated and / or Liposomal forms can help improve absorption.
CoQ10 - There are two main forms of CoQ10—Ubiquinone and Ubiquinol. Standard dietary Ubiquinone CoQ10 absorption is slow and limited due to its hydrophobicity and large molecular weight. Solubilized CoQ10 formulations using Ubiquinol indicate improved absorption in dietary supplements and means that it can be used by the body more easily. (r15)
Vitamin D absorption
Vitamin D is easier to absorb if you eat it with food. Vitamin D is a fat-soluble vitamin, therefore it does not dissolve in water and is best absorbed in the bloodstream when consumed in conjunction with high-fat foods. Vitamin D blood levels increased by around 50% when taken with the largest meal of the day.
Another effective delivery method is Liposomal liquid encapsulated Vitamin D, as it's contained within the outer fat layer of the liposomal membrane, which protects it from harsh digestive processes providing high absorption and targeted delivery. (r16-r17)
Prepared Minerals & Vitamins for Better absorption:
As already discussed, vitamins and minerals are only effectively absorbed when not in competition with others, protected from harsh digestive processes or made more readily bioavailable i.e. in their active form.
When it comes to bioavailable forms(r18-r19), chelated minerals are arguably the most well-known and well-researched example.
Minerals are essential for good health and energy, but many individuals do not get enough of them from their diet alone. They are quite difficult for the body to absorb as when presented in food as part of a molecule, this requires the body to break it down further before the human digestive system can absorb it. Studies have shown that the body may actually use only 10% of mineral intake from food and this number can be even less from supplements.
Mineral absorption takes place through similar receptors in the gastrointestinal tract. High amounts of one mineral may inhibit or slow down the absorption of another mineral. For example, calcium will inhibit iron absorption. To counteract minerals can be synthesised into different forms to help them 'get in' a different way and not compete with other minerals. The chelated form is one of these synthesis methods.
A chelator is a substance composed of molecules that tightly bind to metal atoms (minerals in this example) and force them to follow the chelator wherever it goes - helper molecules that aid minerals on their journey into our bodies.
Chelates bound pairs of two substances (the chelator and the mineral) to increase mineral absorption through the intestinal wall lining into the blood, tissues, and cells. This enables more chelated minerals to reach your bloodstream than your body would typically allow.
The use of chelates within liposomes enables a more economical approach as the liposome protects the mineral and prevents it from being destroyed in your stomach. The mineral has already been pre-absorbed into the Liposome structure, similar to how our cells work. Absorption is improved and reduces the amount of minerals one has to consume.
Most Minerals are available in chelated form, the most familiar of these being:
Although Methylation may appear complicated, it is essentially a simple but vital chemical activity that occurs continuously throughout your body (r20). Methylation is the process of attaching a methyl group to other chemical compounds allowing the body to perform most of its functions. The process helps better absorption as it makes the nutrients more 'active ready' for use.
Constant inflammation places a considerable strain on the body in general, and it can drain your 'methyl pool' (methylated molecules store) needed to assist with various essential processes. If that pool is continuously 'drained' by inflammation, other essential processes, such as tissue repair or neurotransmitter production can be affected. If you have a chronic digestive disorder such as IBD or pernicious anaemia, your absorption of vital nutrients, such as vitamin B12, may also be significantly reduced.
Methylated B12 Vitamins are more bioactive than other forms such as cyanocobalamin, hydroxocobalamin, or adenosyl cobalamin. The term "bioactive" refers to B12 that has already been transformed into a form that is ready to be utilised by the body's cells, instead of needing further processes to make it active. Methyl cobalamin requires little to no conversion and passes through every step of the B12 metabolic pathway without difficulty.
Here is a list of several other methylation nutrient forms:
- 5-MTHF (folate)
- Methyl cobalamin (vitamin B12)
- Pyridoxal 5’-Phosphate (vitamin B6)
- Riboflavin 5’-Phosphate (vitamin B2)
- Vitamin D
Combining Nutrients for Better Absorption
We are regularly looking for ways to make sure our bodies are getting the nutrients needed to stay healthy. But what you might find interesting is that combining certain types of foods or nutrients can help with absorption? For example, pairing a high-fat meal with vegetables or fruit will help get more vitamins into your body because fat helps transport them. Combining nutrients such as vitamin C and iron can also improve absorption rates.
There are some instances where there is no problem with nutrient absorption on its own, but pairing them together can make an already good thing better!
Vitamin C helps Iron Absorption
For people with iron deficiency, a common cause might be not enough dietary animal protein. Plant source iron is less bioavailable than that found in meat and fish. Vitamin C can help improve iron absorption from plant-based foods because it increases stomach acid production, which helps break down food particles, including nonheme (plant) iron. A recent study by Medical News Today (r21) showed that taking vitamin C before a meal containing non-heme (plant) iron increased its absorption by two to three times more than when taken after eating without vitamin C.
Vitamin K2, when used with Vitamin D3, helps Calcium absorption
99% of calcium, the most abundant mineral with our body, occurs in our bones and just 1% within our blood and tissues. Vitamin D is a key modulator in intestinal calcium absorption. The human body also needs vitamin K2 to absorb calcium. Without it, the bones will become brittle and fracture easily. A ground breaking 2017 review (r22) compiled over 80 studies that showed that vitamin D3 and K2 together are greater than the sum of their individual parts. This is likely because vitamin D gets the calcium into the blood, then vitamin K tells the calcium where it is most needed.
Vitamins (A, D, E, and K) & Fats
Fat-soluble supplements, like vitamins A, D, E & K, require fat for better absorption because they bind with it in the intestines before being absorbed into the body. Consuming these vitamins with a meal containing fat, will aid in their digestion. Or if taking them in supplement form, omega 3 oil helps, as well as Liposomes which are tiny spheres of fat that envelope both water and fat-soluble ingredients.
Black Pepper & Turmeric
The active ingredient in turmeric is curcumin, which has been shown to reduce inflammation and help with chronic pain. Curcumin bioavailability is low due to its poor absorption and rapid metabolism. However, black pepper can increase the bioavailability of curcumin.
B Vitamin Complex
B Vitamins are a group of water-soluble vitamins that help make energy from food. The B Vitamins work better synergistically as a group rather than on their own. In other words, if you take one vitamin in the B family, it might not be as effective as when combining it with other B Vitamins. Therefore, it would be best to consider taking all 8 B vitamins together for optimal health and wellness benefits. (r23
Vitamin C & Glutathione
Glutathione helps to protect against oxidative stress and inflammation as well as supporting T-cell immune function. Vitamin C is a popular antioxidant and immune booster, which is essential for good health. In liposomal encapsulated form, which aids better absorption, each product has the other one’s back. Vitamin C helps to protect Glutathione in the tissues (r24), while Glutathione converts worn-out vitamin C back into its active form (r25). The pairing of these two nutrients can help reduce oxidative stress, improve liver function, better immune system function, and enhance cellular protection.
Advanced delivery systems for improved Absorption & Bioavailability
To aid with better transport and delivery of nutrient into the body, there are many different methods that can help. Two forms which have gained recent popularity are that of ‘Timed-Release’ nutrients and Liposome Encapsulation. Here we explore both system:
Timed Release - Timed release supplements are designed to slowly release vitamins or minerals for absorption over a long period of time. This could be a couple of hours or several hours, which will depend on the nutrients (r26)
You might also find time-release supplements being labelled as
A special tablet coating or shell are common methods used to slow the rate of dissolvement.
Water-Soluble Vitamins are generally incorporated with delayed time-release systems as the body does not store them for very long and soon excretes them through the urine. Because of this, water-soluble vitamins need to replacement more often than fat-soluble ones. Using the timed-release method enables the vitamins to be dispersed over a more extended period, allowing for more of the nutrient to be absorbed and not flushed away. Vitamin C and all B vitamins are water-soluble.
Some people are unfamiliar with the term Liposome, when in fact they have been used within the pharma industry for more than 30 years to help with higher absorption of drugs and the target delivery of them into cells. Nutrients such as Vitamin C (r26) as well as some other vitamin and mineral use this ground-breaking oral delivery solution, for being able to quickly deliver nutrients into targeted cells that need them most.
So what are Liposomes? Liposomes are micro-spheres (bubbles) that encapsulate nutrients within them. The Lipids that form the liposome membrane are called "phospholipids". Phosphatidylcholine is the most abundant phospholipid and a main building block of our own cells.
Once consumed in a liquid form, due to this physiological indifference to our own cells, the body rapidly absorbs it. Traditional oral dose forms are absorbed by first-pass metabolism in the liver, where the nutrient (or medicine) is digested and broken down before entering circulation and being delivered to the tissue. Liposomes evade first-pass metabolism and breakdown in the liver by being absorbed through the oral mucosal barrier and lymphatic processes in the gut, which increases oral bioavailability.
Another key benefit to liposomes is in their ability to encase the nutrient protecting it from being damaged and broken during the gut's harsh digestive processes. Once the liposomes have entered the blood, they are then transported around the body target-delivering the nutrients into our cells.
Dietary supplements that use liposomal nanotechnology can have up to 5-10 times the bioavailability of traditional oral supplements.
As you have discovered, there are many factors that can affect how your body absorbs nutrients from foods and supplements. Equally important is how your body is then able to utilise them effectively. Digestion time, medications, lifestyle choices, illnesses are some of the hindrances to effective utilisation. Age is an important factor to take into consideration. As we grow older our organs are not as efficient as they were when we were young. This can result in reduced intake of essential nutrients leading to deficiencies and one of the main causes associated with disease.
We must endeavour to seek ways to optimise our nutrient intake within the body. The most obvious focus should be on the foods we eat within our diet. If needing supplementation then Intravenous is the best delivery form for feeding nutrients directly into the blood, providing 100% bioavailability. It is though costly and highly inconvenient. Oral supplementation will therefore continue to be the preferred delivery for boosting our nutrient intake. It is therefore important when choosing supplements, that you invest time in reading the backs of labels to understand the ingredient forms being used and how nutrients are released in the body.
One thing you can look out for are Liposomal supplements, which are proving to be a popular choice for those seeking a more scientifically advanced delivery mechanism to ensure nutrients reach your cells. Whilst not directly comparable to Intravenous, Liposomal supplements have been shown to be more beneficial than standard powder, tablet and capsule forms. After all, if bioavailability suffers, so does the effectiveness and value for money of your supplements (not to mention your health!).
If you find all this information a little bit too overwhelming, a great place to start could be to visit your local Health Food Store or speak to a qualified Nutritionist and ask them to explain the differences in delivery and ingredient forms.
*The first pass metabolism refers to when a drug/nutrient is metabolised (i.e. turns the nutrient into energy for storing or utilising), which generally happens in the liver. It can happen also in the lungs, gastrointestinal tract, and metabolic active tissues in the body. First pass metabolism could reduce concentrations of the active nutrient from reaching target cells in other parts of the body for its intended bio-therapeutic action.
r1 - https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/drugs-and-nutrition-how-side-effects-can-influence-nutritional-intake/1D2EFD63A3CE7061C72D681AC1348CFE
r2 - https://www.crohnscolitisfoundation.org/diet-and-nutrition/malnutrition-and-ibd
r3 - https://www.nutrition.gov/topics/diet-and-health-conditions/digestive-disorders
r4 - National Institute on Alcohol Abuse and Alcoholism https://pubs.niaaa.nih.gov/publications/aa22.htm
r5 - Caffeine and bone loss in healthy postmenopausal women - https://pubmed.ncbi.nlm.nih.gov/8092093/
r6 - Caffeine decreases vitamin D receptor protein expression - https://pubmed.ncbi.nlm.nih.gov/17223552/
r7 - https://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/the-effect-of-caffeine-on-vitamin-absorption.html
r8 - https://www.health.harvard.edu/newsletter_article/stress-and-the-sensitive-gut
r9 - https://www.nursingtimes.net/roles/older-people-nurses-roles/anatomy-and-physiology-of-ageing-3-the-digestive-system-27-03-2017/
r10 - Biological Evaluation of Liposomal Glutathione https://clinicaltrials.gov/ct2/show/NCT01967667
r11 - Ascorbic acid absorption in humans: a comparison among several dosage forms https://pubmed.ncbi.nlm.nih.gov/7069582/
r12 - Vitamin B12 deficiency – https://www.rcpjournals.org/content/clinmedicine/15/2/145
r13 - Systematic review on daily vitamin B12 losses and bioavailability https://pubmed.ncbi.nlm.nih.gov/23796635/
r14 - Intestinal Absorption and Factors Influencing Bioavailability of Magnesium- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5652077/
r15 - Bioavailability of Coenzyme Q10: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7278738/
r16 - Taking vitamin D with the largest meal improves absorption https://pubmed.ncbi.nlm.nih.gov/20200983/
r17 - Factors influencing the absorption of vitamin D https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5643801/
r18 - https://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/chelated-minerals
r19 - https://www.thegreatcoursesdaily.com/getting-the-most-out-of-minerals-understanding-bioavailability/
r20 - https://commonsensehealth.com/what-are-methylated-supplements-and-their-effects/
r21 - https://lilysoutternutrition.com/7-food-combinations-that-improve-nutrient-absorption/
r22 - https://www.humann.com/nutrition/powerful-combo-vitamins-d3-k2/
r23 - https://www.healthline.com/health/food-nutrition/vitamin-b-complex#benefits
r24 – Vitamin C Is an Essential Antioxidant in the Presence of Glutathione* https://www.jbc.org/article/S0021-9258(20)87425-0/fulltext
r25 - Glutathione Improves the Antioxidant Activity of Vitamin C in Human Lens and Retinal Epithelial Cells https://www.tandfonline.com/doi/full/10.1080/02713683.2020.1809002
r26 - https://www.livestrong.com/article/430058-what-are-time-release-vitamins/
r27 - Influence on Vitamin C Bioavailability https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4915787/