The thyroid ratio
One number that changes meaning depending on which side of four it lands
Of the ratios on a hair tissue mineral analysis, this is the one most closely tied to thyroid activity — and it is read as a direction, not a verdict.
Trace Elements puts the ideal calcium to potassium ratio at 4.2; Analytical Research Labs uses 4. In practice Eileen reads the range between them, 4 to 4.2, rather than a single number.
Trace Elements also publishes an acceptable range of 2.2 to 6.2 around its ideal, which is the wider band a result is judged against.
The same approach applies across the core ratios, and the two laboratories sit close together throughout:
Reading a band rather than a point is the more honest treatment. A result sitting inside 4 to 4.2 is balanced whichever reference your report used; one well outside 2.2 to 6.2 is outside on either.
Ratios before levels. A calcium figure on its own says very little. The same calcium number means different things depending on the potassium sitting beside it, which is the entire reason the ratio exists.
The pattern system Eileen works from names it outright: the Thyroid Ratio, described as relating to how efficient the body's energy production is, where an imbalance can result in a sluggish or an increased thyroid hormonal effect at the cellular level. Na/Mg carries the parallel name, the Adrenal Ratio.
In the lab's own gland table, thyroid activity is read from four indicators, and Ca/K leads them:
The mechanism given is mineral handling rather than anything mystical. Increased thyroid activity promotes calcium and magnesium excretion while increasing phosphorus retention, which pulls Ca/P down. Increased adrenal activity raises Na/Mg and reduces Ca/K.
This is the part worth being careful about. A ratio above or below its ideal is an indication of a direction of activity in the lab's interpretive system — what the laboratories themselves print as a trend. A low thyroid trend is a direction the mineral pattern points. It is not a thyroid diagnosis, it does not replace thyroid bloodwork, and a hair tissue mineral analysis is a screening test.
That distinction is the whole reason the word exists on the report. The trend belongs to the pattern, not to the person reading about it.
The value of the number is that it is a pattern held over two to three months of hair growth, which is a different kind of information from a single morning blood draw. The two answer different questions.
Anything about your thyroid belongs with your own licensed provider. What this page can tell you is how the ratio is calculated and what the lab's literature says it indicates.
Ca/K is one of a small set that carries most of the interpretation: Ca/P (ideal 2.6), Na/K (ideal 2.4), Zn/Cu (ideal 8), Na/Mg (ideal 4) and Ca/Mg (ideal 7).
The glands are read together rather than in isolation. Ca/K appears in the parathyroid, pancreas, ovarian and adrenal rows as well as the thyroid one, which is precisely why a single ratio is never read alone.
The first thing I check is whether calcium and potassium moved together or in opposite directions since the last report. A ratio can shift because one number rose, or because the other fell, and those are not the same situation at all.
I have also learned to slow down when Ca/K sits very close to 4. A number sitting on the line is not a subtle finding — it is an unclear one, and the honest response is to look at the other three thyroid indicators before saying anything about it.
On the Trace Elements set, 4.2, with an acceptable range of 2.2 to 6.2. Other laboratories publish different ideals and the figures should not be mixed.
No. A ratio above 4 is listed as an indicator of decreased thyroid activity within the lab interpretive system. That is a pattern reading, not a diagnosis, and it does not replace thyroid bloodwork.
Because the same calcium figure means different things depending on the potassium beside it. The lab literature is explicit that the relationship between nutrients matters more than any single level.
A hair tissue mineral analysis reports Ca/K alongside the other core ratios, so the thyroid indicators can be read together rather than one at a time.
Published 2026-08-30 · Updated 2026-08-30
By Eileen Durfee — Practitioner, NBS (Nutritional Balancing Science), NASM-CPT; wellness educator, inventor and author.
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. Hair tissue mineral analysis is a screening test and is not diagnostic; anything medical belongs with your own licensed provider. Wellness Shopping Online is operated by Nuco Enterprise Solutions LLC.
