You Can Take the Supplement and Still Not Absorb It

What I look at, and why it starts before the labs

Before I read anything, I ask four questions. Are you having any trouble with your digestion? Any heartburn, or any pain in your abdomen after you eat? Any bloating? Are you having a bowel movement every day?

They take about a minute, and they are not part of a standard workup, so most people arriving in her position have never been asked them. She had not been. The answers change how I read the panel, so I would rather have them before I start reading it.

The four questions, before the labs

Are you having any trouble with your digestion?

Any heartburn, or any pain in your abdomen after you eat?

Any bloating?

Are you having a bowel movement every day?

I also ask what else you are taking. Acid-blocking medication is the one that comes up most: the proton pump inhibitors, omeprazole and pantoprazole, and the H2 blockers alongside them. They work by reducing stomach acid, and stomach acid is part of how both B12 and iron are absorbed in the first place. Metformin interferes with B12 by a different route.

Antibiotics do something different from either. They do not distinguish between the bacteria you wanted rid of and the ones further down doing useful work, so they change what is living in your gut. How much that matters for absorption in any one person is not something I can tell you precisely. It is part of why I ask.

Somebody on long-term acid suppression can be short of B12 in a way the standard blood level does not show. None of this is a reason to stop a medication you were prescribed for a reason, and I would ask you not to on your own. It is a reason to know it is in the picture.

What else you are taking

Acid blockers

The proton pump inhibitors, omeprazole and pantoprazole, and the H2 blockers alongside them. Stomach acid is part of how both B12 and iron are absorbed in the first place.

Metformin

Interferes with B12, by a different route again.

Antibiotics

They do not distinguish between the bacteria you wanted rid of and the ones further down doing useful work, so they change what is living in your gut.

This is not a reason to stop anything

None of this is a reason to stop a medication you were prescribed for a reason, and I would ask you not to on your own. It is a reason to know it is in the picture.

Then I look at the numbers.

The nutrients themselves. Ferritin, B12, folate and vitamin D. I go through them line by line first, because each has its own list of ordinary explanations worth working through properly. Then I step back and read the panel as a whole. If everything on it is low at once, that is a finding in its own right, and not one any of the individual lines was making.

Homocysteine. B12 and folate can look adequate in the blood and still not be doing their job inside the cell. Homocysteine gives me a second window on that, a functional read rather than a level. It is not specific to those two vitamins, so I read it alongside them rather than in place of them. The same distinction runs through the thyroid piece: what is circulating and what is arriving are different questions.

The mistake is repleting into a gut that is not absorbing

This is the part I would most like to change about how this gets managed. Four low numbers genuinely do call for four corrections. The problem is doing the correcting first and the asking afterwards.

Iron is where it shows up most clearly. If somebody is not absorbing well, more iron by mouth is not a stronger version of the same plan. It is the same plan, delivered to the same closed door, and oral iron reliably brings side effects of its own. So in that person I want the absorption side dealt with before we push harder on the iron.

That is not the same as leaving the iron alone, and it is the part people hear wrong. The iron still needs correcting and it will be. It is only a question of what happens first. It sounds like the slower route. In practice it is the faster one, because the second attempt is the one that works.

There is one exception and it matters. When iron is severely low, I do not spend months working on absorption first. In that situation I replete it directly, with an infusion that goes around the gut entirely. Absorption is most of the story through the middle of the range. At the bottom of it, getting the iron in is the story.

"Fix the gut first" is not one rule

It gets repeated as though it applied to everything, and in my practice it does not. The exceptions are the useful part.

It is true of iron through most of the range. It is not true of B12 or of vitamin D, and in both of those it is the same fact about absorption pointing the opposite way.

Take B12. It has the most complicated absorption pathway on that panel, because it depends on a specific mechanism in the stomach and small intestine that ordinary things interfere with, the acid blockers above among them.

You would reasonably conclude it is the strongest case for fixing the gut first. It is the opposite. When absorption is the problem for B12, the answer is to go around the gut rather than repair it and wait. Somebody with neurological symptoms and a low B12 does not have months to spend on the scenic route.

Vitamin D behaves differently again. If it is low, I treat it, and I do not hold that decision hostage to what the digestive system is doing.

What does waiting cost?

Waiting costs little - deal with absorption first

Iron, through the middle of the range

I want the absorption side dealt with before we push harder on the iron. That is not the same as leaving the iron alone. The iron still needs correcting and it will be. It is only a question of what happens first.

Vitamin D, low

If it is low, I treat it, and I do not hold that decision hostage to what the digestive system is doing.

B12, when absorption is the problem

Go around the gut rather than repair it and wait. Somebody with neurological symptoms and a low B12 does not have months to spend on the scenic route.

Iron, severely low

I do not spend months working on absorption first. In that situation I replete it directly, with an infusion that goes around the gut entirely.

Waiting is the thing you cannot afford - go around the gut

Same organ, same mechanism, three different answers about what to do first. This is the part worth holding on to: for two of those three nutrients, fixing the gut first would cost you months you did not need to spend.

If there is one rule underneath all of it, it is that you go around the gut when waiting is the thing you cannot afford. That is why a severely low iron gets an infusion, and why a low B12 with neurological symptoms gets an injection. It is the same reasoning arriving at the same answer from two different directions.

Knowing how a nutrient is absorbed does not by itself tell you what order to do things in. Working out the order is most of the job, and it is the part that gets skipped.

Your gut and your nervous system are in constant conversation

There is a second reason I pay this much attention to digestion, and as a neurologist it is the one I find hardest to put down. The gut is also known as your second brain, and that is not only a turn of phrase. It runs on its own dense network of nerves, and it makes signaling molecules of its own.

Most of the body’s serotonin is produced in the lining of the gut rather than in the brain. It does not travel up and become the brain's supply, because it cannot cross into the brain. It works where it is made, and part of what it acts on are the nerve fibers running from the gut up to the brain. That is the wiring.

The traffic runs both ways, and I see both directions in clinic. Stress very often arrives as a gut symptom first. And a gut that is not working well is itself a stress on the whole system. In the patients I see, that turns out to be sitting underneath things that do not look like digestive problems at all. It is why I ask about digestion even when somebody has come in about something else.

It deserves more room than it can have inside an article about absorption, so I will come back to it on its own.

The gut is a barrier before it is anything else

Digestion is the obvious work, and the nervous system is not the only other thing going on at that wall. The intestinal wall is also a barrier, a border with a great deal of traffic. A very large share of the immune system is stationed along it, which is not an accident of anatomy. That is where the body meets most of what comes in from outside.

When that barrier is less intact, more of what is in the tube reaches the immune tissue on the other side. You will have seen this called gut permeability, or "leaky gut." The immune system responds to what arrives, because responding is its job. A wall in that state is also worse at the job this article is about. The same damage that lets the wrong things through is damage to the surface that is supposed to be absorbing.

How much that contributes to autoimmune disease is still being worked out. What I will say is that the gut and the immune system are in continuous contact, and in a patient with an autoimmune condition that is not something I am willing to leave out of the picture. It is why one of the five pillars of the Meliora Method is called Gut and Detoxification Optimization, with both of those things inside one pillar rather than sitting in two.

I should say what I mean by detoxification, because the word gets used in a lot of different ways. I mean the ordinary, continuous work the liver, the kidneys and the gut are already doing to clear what the body is finished with. It runs whether or not anyone is paying attention to it, and it runs through the same wall the immune system is stationed along.

So I read the three together: the barrier, the immune tissue behind it, and the clearance work downstream. In the patients I see they do not move independently.

Three jobs at the same wall

The barrier

The intestinal wall itself, and how intact it is. The same damage that lets the wrong things through is damage to the surface that is supposed to be absorbing.

The immune tissue behind it

A very large share of the immune system is stationed along that wall, which is not an accident of anatomy. It is where the body meets most of what comes in from outside.

The clearance work downstream

The ordinary, continuous work the liver, the kidneys and the gut are already doing to clear what the body is finished with. It runs whether or not anyone is paying attention to it.

Why they sit in one pillar

In the patients I see they do not move independently, which is why Gut and Detoxification Optimization is one pillar of the Meliora Method rather than two.

One version of this has a name and a test. Celiac disease is an autoimmune reaction to gluten that damages the lining of the small intestine, and damage to that lining is malabsorption by definition. If that is the question, it is worth answering properly with a gastroenterologist rather than by trying a diet and going on how you feel.

A test has to change what I do next

I do not run stool panels or microbiome sequencing. What lives in your gut does matter, and I have just said as much about antibiotics. What I have not found is a test I trust enough to act on. The same goes for the mail-order kits patients bring me. That is a statement about the tests available today, not about the idea. If one arrives that I can trust, I will run it.

I also have a habit of trying a test on myself before I ask a patient to do it. I bought a microbiome kit for exactly that reason. It is still sitting there unopened, because working out what it wanted from me looked like more trouble than it was worth. If it is too cumbersome for me, I am not going to hand it to somebody who is already unwell.

So the question I put to every test is what will this actually tell me, and would I do anything differently once I knew. If I cannot answer the second half, I do not order it. The same reasoning runs through what I wrote about stress.

It works in both directions, and that is the part worth saying plainly. It is also why the panel I do run is broader than most. A full hormone panel, thyroid antibodies, a functional marker like homocysteine: none of those get ordered as a matter of course. The same standard that rules one test out is what puts a great many others in.

For now I assess digestion through the history and the clinical picture, and treat it on that basis, which has been the more useful route by a distance.

What I do not order

Stool panels

Microbiome sequencing

The mail-order kits patients bring me

What I do order

Ferritin, B12, folate and vitamin D

A full hormone panel

Thyroid antibodies

A functional marker like homocysteine

What actually helps

Most of what repairs a gut is food. Enough protein, enough fiber, and simply enough food, because a body that is undereating has nothing spare to put into repair. It is unglamorous, and it is where most of the work is.

Sometimes I add a supplement aimed at digestion itself. Not for everybody, and what I reach for depends on whether there are symptoms at all. Somebody with bloating, heartburn, or a bowel pattern that has changed needs a different thing from somebody with no digestive complaints whose nutrient levels keep coming back low anyway.

That second group is larger than people expect, and easy to miss precisely because nothing hurts. Which is why it is a decision to make with somebody who knows your history, rather than from something you read online.

Then correcting what is low, in the right order for that nutrient, and re-checking to confirm it came up rather than assuming it did. A recheck is not administrative. It is the only way anyone finds out whether the first plan worked. The woman at the top of this article did get hers. What never happened was anybody asking why it had not moved.

And treating what is genuinely driving it underneath, which is sometimes a hormonal picture, sometimes an immune one, and often a load that has been carried too long. The gut is quick to show that it is under strain and slow to be the only thing that is.

What actually helps, in order

1

Food. Enough protein, enough fiber, and simply enough food, because a body that is undereating has nothing spare to put into repair

2

Sometimes a supplement aimed at digestion itself, and which one depends on whether there are symptoms at all

3

Correcting what is low, in the right order for that nutrient, and re-checking to confirm it came up

4

Treating what is genuinely driving it underneath, which is sometimes hormonal, sometimes immune, and often a load carried too long

The bottles in her bag were an answer to "what is low." They were never going to be an answer to "why is none of it getting in."

Those four bottles were not a mistake. They were a reasonable response to the question "what is low," and that question had been asked and answered properly.

The question underneath it was why four things were low at once in someone who eats well. That one has a different answer. It changes the order things are done in, and often it changes what I end up suggesting she take. Whether something is getting in and whether it was the right thing to begin with are two separate questions, and both deserve asking.

Either way you should finish knowing what your own results mean and why the plan is in the order it is in, which is the whole idea behind how we practice. If your labs keep coming back low and the reason has not been worked out yet, that is worth looking at properly, or you can start here.

The patient described here is a composite. Dr. Rowena Chua is the founder of Meliora Integrative Medicine in Evanston, IL and is triple board-certified in Neurology, Integrative Medicine, and Obesity Medicine.