Open a periodic table. Find zinc. Now look directly below it. That’s cadmium.
They sit in the same column because they’re chemically similar. Similar enough that when the body runs low on zinc, it will use cadmium on zinc’s binding sites. The body doesn’t know it’s making a terrible trade. It just knows the seat is empty and something needs to fill it.
Zinc and cadmium are both divalent metals in group 12 of the periodic table. They share enough chemical properties that they can swap on binding sites within the body’s proteins and enzymes. Zinc is estimated to bind about 10% of the entire human proteome. It provides structural support, drives enzymatic reactions, and regulates protein function across virtually every system. When zinc is present, things work. When it’s not, cadmium can slide in.
A 2021 study published in PNAS described cadmium as a “zinc mimetic.” It showed that cadmium can bind to and activate zinc receptors, hijacking the body’s own zinc-sensing system. The researchers noted that since roughly half of all enzymes are predicted to bind a metal ion, cadmium may substitute for zinc in metalloprotein binding sites, causing protein dysfunction. It fits. It binds. But it doesn’t do the job properly.
And the research on what happens in a zinc-depleted body is pretty alarming. A study published in the Journal of Toxicology and Environmental Health found that a zinc-deficient diet markedly enhanced cadmium accumulation in the liver, kidneys, and testes. The less zinc available, the more cadmium the body absorbed and stored.
This isn’t just animal data. A study using NHANES data from over 6,600 US adults, published in the Journal of Nutrition, found that greater zinc intake was associated with significantly lower cadmium burden. The researchers identified that zinc transporters ZIP8 and ZIP14 are partly responsible for cadmium absorption, and that zinc is the primary mineral that blocks cadmium from using those transporters to get in. When zinc is present at the door, cadmium can’t enter as easily. When zinc is missing, the door is wide open.
Now connect this to how copper toxicity depletes zinc. Hormonal birth control depletes zinc. Pregnancy depletes zinc. Chronic stress depletes zinc. Long term vegan and vegetarian diets are naturally low in zinc. Alcohol and excessive caffeine deplete zinc further. Every one of those situations makes cadmium accumulation more likely. And cadmium is not a mineral the body clears easily. It accumulates primarily in the kidneys and bones. It’s been linked to kidney disease, osteoporosis, hypertension, diabetes, and multiple cancers including lung, breast, and endometrial.
On an HTMA test, cadmium isn’t always well excreted through the hair, so even a small elevation is worth paying attention to. But the bigger picture is the zinc status. If zinc is chronically low and copper is chronically high, the conditions for cadmium accumulation are already in place whether you can see the cadmium on the panel yet or not. This is why balancing the main four minerals is always recommended first before heavy metal detoxing. You can’t pull cadmium out of binding sites if there’s no zinc to take its place. The body put cadmium there because it was the only option available.
Give it a better one, and the whole equation shifts. Have you gotten your HTMA test yet?