Every station one at a time, with a name and a place: the transport protein at the gut wall, the channel net inside the mineral, the messenger out of bone tissue and the two proteins that settle the way back inside the kidney.
Technical terms are explained where they first appear. This text does not stand in for personal advice.
Phosphorus does not reach the body as a free element but bound into compounds from food. In the small intestine it is loosened from them and then has to pass the cell layer of the gut wall before it arrives in the blood. Two routes stand open for that, and they differ markedly in pace and in how far the cell can steer them.
On the side of the cell facing the gut contents sits a protein from the SLC34 family that takes up phosphate together with sodium ions. The driving force comes not from the phosphate itself but from the sodium gradient, which a pump on the opposite face of the cell holds up at an energy cost. If that gradient collapses, uptake by this route stalls with it.
Alongside it, part of the phosphate simply slips between the cells, following its own concentration gradient. The cell has little say over this route; it counts for more the more phosphate happens to be dissolved in the gut contents at that moment. On an ordinary mixed diet both routes contribute side by side, and their ratio shifts from meal to meal.
By far the largest share of the phosphate in the body sits bound in the skeleton, alongside calcium in a crystalline compound named hydroxyapatite. Seen from outside, this material looks like a finished component. In fact it is shot through with cells and with fluid, and that is precisely why anything in it can move at all.
While the mineral is being laid down, individual bone-forming cells stay behind in the substance taking shape and become enclosed by it. From then on they are called osteocytes and sit in small cavities, the lacunae. Fine little channels tie these cavities to one another and to the surface; the cell extensions reach through them and pass substances back and forth. The fluid in this net is the place where bound and dissolved phosphate meet each other at all.
Mineral is not meant to deposit at any spot whatever. An opponent that the cells themselves release to the outside sees to that: pyrophosphate, two phosphate units tied through a single oxygen atom. As long as it is present in the surroundings, deposition stays held back. An enzyme on the outer cell envelope, tissue-nonspecific alkaline phosphatase, splits that tie open again. What counts is therefore the ratio between tied and single phosphate — not the quantity of one or the other taken on its own.
A tissue that gives off hormones is something one associates with glands rather than with the skeleton. In fact one of the signals that has a say in the phosphate stock on hand comes from exactly those cells that sit shut into the mineral.
Osteocytes make a protein that the scientific literature lists under the short name FGF23. When the quantity of dissolved phosphate rises, they give more of it into the blood. The hormone reaches the kidney and takes hold there on the cells of the first tubule segment. This connection was first described around the year 2000, in the course of work on rare inherited peculiarities of the phosphate balance.
FGF23 docks onto a receptor of the kidney cell but does not manage without a partner: a membrane protein named Klotho. Only together do the two form a binding site that this hormone fits. Where Klotho is absent from a tissue, the same hormone passes the cell by although it is present in the blood. That is why the signal takes hold almost only where both parts sit next to each other in one and the same membrane.
The kidney filters a considerable quantity of phosphate out of the blood every day. The body keeps most of it all the same, because it is gathered in again immediately after the filtering.
The first segment of the kidney tubule carries densely packed protrusions on its inner face that enlarge the area many times over. Two related transport proteins from the same family as in the small intestine sit in this membrane. Both take up phosphate together with sodium and hand it back to the blood on the far side of the cell.
If FGF23 arrives at this spot, the transport proteins are pulled out of the membrane and taken apart inside the cell. Fewer carriers mean that a larger share of the filtered phosphate stays in the tubule and is given off with the urine. The body thereby holds a way of setting the stock lower without altering anything at the skeleton itself.
| Protein | Place | Job |
|---|---|---|
| SLC34A2 | cells of the small-intestine wall | takes up phosphate together with sodium out of the gut contents |
| SLC34A1 and SLC34A3 | first segment of the kidney tubule | fetch filtered phosphate back out of the tubule |
| Alkaline phosphatase, tissue-nonspecific form | outer face of bone-forming cells | splits pyrophosphate into single phosphate units |
| FGF23 | osteocytes inside the mineral | messenger from bone tissue to the kidney |
| Klotho | membrane of the kidney cell | partner without which FGF23 does not bind there |
Simplified compilation drawn from the physiological literature. Not one of these names occurs in the legal text.
Up to here the subject has been biochemistry. The part that may be used in law is a good deal shorter: one single sentence that names a mineral and a state, and nothing else.
Word for word
Phosphorus contributes to the maintenance of normal bones
EU-authorized wording · Regulation (EU) No 432/2012
Before a phrasing of this kind may be used at all, the European Food Safety Authority assesses the research on hand for one single mineral and one single subject area. Only afterwards does the European Commission enter the sentence that came out of it on the list of permitted statements. From that moment the text is fixed.
| Covered by the wording | Not covered by the wording |
|---|---|
| a documented contribution to holding the ordinary state | a change in that state |
| adults in general, with no distinction by age or gender | one particular group of people or stage of life |
| an otherwise adequate intake as a precondition | a quantity above which something else is meant to follow |
| phosphorus as the only mineral named | mood, sleep or concentration |
Ankeritara names no milligram figure and no list of foods, and does so on purpose. A single number would read the same for every reader, which does not do the matter justice; placing your own intake belongs in a conversation with a nutrition professional or a physician.
The transport proteins, the channel net and the two hormone components from the earlier sections are specialist knowledge out of the literature. They show why research took an interest in this element and the skeleton. Not one of them turns up in the authorized sentence, and Ankeritara does not ascribe them to it either.
No. The authorized sentence names only the mineral and the state it refers to. Both proteins belong to the background that the scientific literature describes, and they are named on these pages purely for context.
Nothing in the wording says so. What is described is a process that runs anyway on an adequate intake. An intake beyond that is not provided for in the text and is not held out here either.
Because a single number would read the same for every reader and therefore says little. Anyone wanting to place their own intake is better served by a nutrition professional or a physician than by a text on the internet.
Both hang together through the same dissolved quantity. What the skeleton gives off runs through the blood and is either fetched back in the kidney or passed along. That link explains why a text about bone would stay incomplete without a section on the kidney.
Every authorized phrasing was reviewed for one single mineral and holds for that one alone. Other minerals occur in the skeleton as well and some of them carry their own, separately reviewed sentences; Ankeritara does not mix those with the one quoted here.
What stands here is the shortened version. Access holds every section at full length, both tables, a list of the scientific literature drawn on and the legal text in its original wording.
$49.00
One-time access · Digital information product
Questions About AccessIf your mind changes within fourteen days, an informal note is enough and the amount comes back in full. That is a promise we give of our own accord, and the Refund Policy sets out how it runs.
This page places a phrasing laid down in law in its scientific context. It gives no diagnosis, recommends no therapy and at no point steps into the place of a medical examination. Where complaints already exist, during a pregnancy, while nursing or on long-term use of medicines, every question about diet belongs in a practice or a pharmacy.
Food supplements replace neither a varied diet nor a sound way of living. The daily quantity stated on the packaging should not be exceeded; store them on a high shelf, away from small hands. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
In some cases the route here runs across a bought advertising space. Whoever books such a space rents room and nothing else: content, phrasing and responsibility lie with the provider named in the business information alone. That an ad leads to this page says nothing about where the companies named in the heading of this section stand on its content; read it before publication they did not.
An unclear passage in the text, a question about the purchase or a matter concerning the handling of your data — put it down here. On sending, your mail program opens a draft that you can look over once more before it leaves.
A note reaches us without the form as well — the address is [email protected].