Calcium Is Not Only for Bones

"Make sure you get enough calcium."

Most people take this to be about bone. It is not wrong. But among the things calcium does in the body, bone is closer to the store, and the work that matters most goes on elsewhere.

A cell begins its work with calcium

For a cell to do anything, a signal has to come. The signal used most widely for this is the calcium ion.

A cell ordinarily keeps calcium inside itself very low — more than ten thousand times lower than outside. So even a small opening sends the inner level sharply up. That moment is the signal.

There are several such doors in the cell membrane. Some open when voltage changes, some when a particular substance comes and binds, and some when they are pressed or pulled. (Where a Pushing Force Speaks to the Cell)

When the door opens, what that cell was for switches on

This is the part I hold to.

Calcium coming in does not make every cell do the same thing. What switches on is the work that cell was already for.

• In a nerve cell, passing the signal on to the next one
• In an immune cell, defending and engulfing
• In a secreting cell, hormone or digestive fluid going out
• In muscle, tightening or releasing

The same door opening brings about something different in each place. So knowing that a compound opens a particular channel does not by itself tell you what will happen in the body. Which cell it opened in decides the result.

So it does not reduce to one action

In describing a medicinal material we often say something like "this acts on the vessels." Convenient, and half true.

The door opened by ginger's pungent compound is the same channel that chilli's pungent compound binds to — TRPV1. And that channel is not only in vessels. It is at the endings of sensory nerves, in the lining of the digestive tract, in immune cells. One compound switches on a different thing in each of several places.

So a description written as one representative action is a summary, not the whole. What actually shows up is what happened in several places, bundled into a single result.

Tip toward acid and the doors behave differently

One more thing overlaps. Ions move differently according to the surroundings.

A place with inflammation tips toward acid — meaning hydrogen ions increase — and those hydrogen ions are themselves the key that opens certain channels. The same stimulus draws a larger response where the place has tipped that way.

That a sore place is unusually touchy owes something to this as well, not only to the nerve side. The surroundings there have lowered the threshold.

More is not better

Saying calcium is a signal also means it has to come in briefly at the right time and leave to be a signal at all.

When calcium stays high inside a cell for long, it stops being a signal and becomes a burden. Let that state run on and the cell's energy-making falters first, and past a point it goes the way of clearing itself away. This is what happens in tissue where blood has been short for a long time. (When the Blood Comes Back It Hurts More)

So what the body minds is less the total than the opening and closing. A normal calcium figure on a blood test can sit alongside a very different state inside and outside the cells.

Where ions come into my thinking

I see ions as switches rather than nutrients. Treated only as something to top up when short, a good deal gets missed.

I look at what is opening and closing those doors, and at how the surroundings there have moved the threshold. It is why the place to work on differs even when the symptom is the same.

When to see a doctor first

If your hands and feet go numb and the muscles stiffen, if consciousness clouds, or if you are severely dizzy — before a story like this, examination and testing come first. If you are taking anything, please tell me what it is.

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Sources

• That pressing force opens ion channels directly, and that this bears on the regulation of blood pressure, breathing and the bladder — the 2021 Nobel Prize in Physiology or Medicine announcement — The Nobel Committee
• A study showing how ginger's pungent compounds open the same channel as chilli's (cell stage) — British Journal of Pharmacology, 2019

Written by Dr. Heo Ji-young (Ph.D. in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)