What is “Bioavailability”? Supplement Fundamentals In Under 5 Minutes!

What is “Bioavailability”? Supplement Fundamentals In Under 5 Minutes!

Simply put, Bioavailability refers to the amount of a substance that your body can use after you have ingested or administered it.

The gold standard of “bioavailability” is from an IV.

You get 100% of a drug or substance in your body once you inject it into your veins and it begins to circulate.

Everything else has to be determined by how close it can get to that concentration.

For example, if you ingest something that has 100mg of a substance,
(like a specific vitamin, or mineral)

After digesting it, You may only get 75% of the substance that you wanted!

However; if you were to take an IV of that Vitamin or mineral, it would have been 100%

meaning that the oral bioavailability of that substance is 75%

If you’re asking: “If it’s supposed to have 100mg, but you only absorb 75% isn’t it misleading to label it as 100mg instead of 75mg?

the answer to your question is:

Not at all!

When we look at some of the factors that affect bioavailability we’ll have a much clearer picture!

Factors affecting supplements bioavailability.

A series of cogs in a machine meant to symbolize the complexity of bioavailability.
Each cog represents one of the very small interactions between digestion, absorption, interaction and excretion.

When taking supplements 99% of the time we see that people are taking supplements in the forms of vitamin pills or powders, meaning that they are taken orally.

These are just SOME of the pros and cons of taking supplements orally:

Pro’s of oral supplementationCon’s of oral supplementation
Generally the safest method of administrationTypically has a slower rate of absorption/metabolism
a convenient method of administrationVariable rates of absorption (See below)
Typically the most easily accessible form of supplementationPotential for Gastric irritation
Taking Supplements orally (whether as powder or pill)

May be affected by overall gut health (IBS, Leaky Gut, poor gut flora, etc)

When we consume something via our mouth, assuming that we aren’t taking a sublingual*, the product will have to be digested by our stomach.

However; it’s not always as simple as being broken down by our stomach acid, getting absorbed by our intestines, and reaching our bloodstream to exert its effects.

Issues like IBS, Leaky Gut, or having a lack of appropriate bacteria in your stomach could ultimately lead to complications with absorbing some products!

Example: Vitamin B12 and the gut

Although long, this is STILL a very strong oversimplification of the process,
when we consume Vitamin B12 it first needs to bind to an enzyme called “haptocorrin”

Vitamin B12 binds with haptocorrin to be protected from the stomach acid destroying it.

In our stomach, we also have something called “intrinsic factor” being produced, which will become necessary once we reach the small intestine.

In the small intestine, our pancreas will release something called a “trypsin” trypsin is an enzyme that will break down the haptocorrin that’s bound to our vitamin B12.

Now that we’ve gotten away from the stomach acid and we have free vitamin B12 in the small intestine, it can bind with the intrinsic factor that’s traveled from the stomach into the intestinal tract.

Once we have Vitamin B12 bound to the intrinsic factor, it can travel safely to the end of the small intestine where it will be transported into the mucus linings.

Here, the Intrinsic factor is broken down and vitamin B12 is either metabolized for use or is bound to another transporter protein so it can circulate until it’s needed for use.

The takeaway from vitamin B12 example

A LOT has to happen for something even as simple as vitamin B12 to be properly digested!
If any of those steps (and more that I’ve left out for brevity) is disrupted we lose a LOT of B12!
This isn’t even factoring in things like specific vitamins impact on the absorption/digestion either!

*(sublingual’s are a product designed to sit under our tongue and absorb into the veins in the mouth to reach our blood and circulate freely)

May be affected by genetics

Properly encoded genes make sure we have no faulty enzyme reactions and get sufficient utility of everything in our body.

Simply put, our genetics regulate EVERYTHING in our entire body.

Our genes will be responsible for encoding everything from what color our eyes are, to the way we metabolize certain drugs or foods!

One of the more popular gene mutations that affect nutritional status is the “MTHFR” gene mutation.

The MTHFR gene is responsible for delivering our DNA’s code to produce the enzyme called “MethyleneTetraHydroFolate Reductase”

This enzyme is responsible for the metabolism of folate and plays a role in the conversion of homocysteine into methionine.

Without proper regulation or encoding, we may face problems with having enough folate, despite a “sufficient” intake on paper.
Asides from the impacts on folate status, It can also contribute to high levels of homocysteine in the blood which can be equally deleterious.

Some people have variations in the gene called SNPs (single nucleotide polymorphisms) either as C677T or A1298C, each having potential complications as a result.

With adequate knowledge of our own genetic limitations, however; we can potentially circumvent deficiencies by supplementing with different forms of supplements and/or providing additional supplements and nutrients that work synergistically.

(For example, taking “L-5MethylTetraHydroFolate” instead of “Folic acid” or consuming betaine rich food/supplements to help with methylation processes)

Now, considering this is a SINGLE gene mutation for an enzyme, imagine the likelihood of the BILLIONS of enzyme activities going on inside of our body.

It should be a bit easier to imagine that one small hiccup in the whole system can bottleneck a lot of our interactions that would affect the absorption of our supplements.

May be affected by nutritional status

Alongside genetics affecting the digestion of supplements, insufficient nutritional status can potentially affect digestion or metabolism.

When breaking down a substance, the body may require trace minerals or vitamins for specific enzyme reactions or for transportation.

Without having an adequate supply of these co-factors for enzymes to do their job, they just won’t.

For example, insufficient thiamine status can have a dramatic impact on our metabolism of carbohydrates, fatty acids, and amino acids.

If left unaddressed it can lead to complications like beriberi or brain damage in the form of Wernicke encephalopathy.

Now for some vitamins or supplements, one can potentially get away with “Mega-dosing”, or consuming a bolus amount at one time, to circumvent the need for enzymes to transport across membranes.

This is due to passive diffusion, as opposed to active transport mechanisms that are required by the enzymes/specific transport channels.

However; this is typically only done with water-soluble vitamins, as mega-dosing fat-soluble vitamins or anything with an upper-tolerable limit can often have toxicity concerns.

May be affected by multi-organ health

Lastly, the digestion of certain supplements can be impacted by damaged organs.

The liver is usually only highlighted for its role in drug metabolism but is also a pivotal part of our metabolic health.

Whether it’s assisting with the metabolism of Vitamin A, D, or Zinc or acting as a storage unit for some vitamins it is one of the hardest working organs in our entire body.

Alongside the liver, the kidneys play an incredibly important role in the metabolism and circulation of vitamins/minerals (outside of just excreting the excess as waste)

Outside of damage being done from alcohol, medications, or things like cancer affecting these systems other factors to organ health also play a role.

Things like Bariatric surgery also DRAMATICALLY affect the digestion and metabolism of what you consume.

In Conclusion:

There is a lot of factors in our body that affects a supplement’s bioavailability.

Everything we consume must go through a series of systems first.

After It gets processed by our bodies digestive system, THEN it can potentially have the desired impact we have in mind.

This is just a BRIEF overview of SOME factors affecting bioavailability.

It also turns out there is a LOT that we can do to help further IMPROVE bioavailability.

If you’re interested in finding out some of the ways to easily do this, make sure to check back in!

A lot of supplements will be covered in the future!

Have any comments or questions? let me know on this post!

If there’s a specific supplement or vitamin you would like to know more about, please feel free to ask below or by using the contact me form on the top right of the website!

Until next time, Toodles!

Leave a Reply

Your email address will not be published. Required fields are marked *