Most of us carry an assumption: that if we eat our vegetables, we are giving our bodies what they need. For most of human history, that assumption was correct. The soil held what the plant needed, the plant held what we needed, and the cycle sustained itself.
That cycle has been breaking down for decades. The vegetables are still there. The minerals, in many cases, are not.
A carrot pulled this morning is the same color and the same weight as a carrot pulled in 1940. The difference is only visible in the records, and the records have been kept long enough to show it.
The Numbers Are Hard to Ignore
The most recent measurement runs to 2019. Anne-Marie Mayer, Liesl Trenchard and Francis Rayns of Coventry University compared three editions of the United Kingdom's official food composition tables — 1940, 1991 and 2019 — and published the result in the International Journal of Food Sciences and Nutrition in 2022. Over those eighty years, every mineral they measured fell except phosphorus. Sodium dropped 52 percent, iron 50 percent, copper 49 percent, magnesium 10 percent. Water content rose. The foods grew wetter and thinner at the same time.
In 2003, David Thomas compared the 1940 and 1991 editions of those same British tables — 27 vegetables, 17 fruits, 10 cuts of meat — and published in Nutrition and Health. Vegetables had lost, on average, 76 percent of their copper, 46 percent of their calcium, 27 percent of their iron and 24 percent of their magnesium. Carrots alone gave up 75 percent of their magnesium and 75 percent of their copper. Iron in meat fell 54 percent, and Thomas called that cause unknown.
The American records tell the same story. In 2004, Donald Davis and colleagues at the University of Texas compared USDA nutritional data for 43 garden crops between 1950 and 1999, publishing in the Journal of the American College of Nutrition. They found measurable declines in protein, calcium, phosphorus, iron, riboflavin and vitamin C across the board.
The three sets of figures differ because they weigh different foods over different spans. Thomas counted vegetables to 1991. Mayer counted fruit and vegetables to 2019. Davis counted American garden crops to 1999. They share the direction: down, across two countries, three teams and eighty years.
What Changed in the Soil
The story begins underground, with what farming became in the twentieth century.
For most of agricultural history, land was rotated, rested, and returned to. Animal manure, composted plant material, and diverse cropping rebuilt what each harvest took. That changed with the industrialization of agriculture. Modern conventional farming relies heavily on NPK fertilizers (Nitrogen, Phosphorus, and Kalium — the chemical name for potassium), which grow large, fast, visually impressive plants. What NPK does not replace is the full spectrum of trace minerals: magnesium, zinc, selenium, boron, manganese, copper, chromium, and the dozens of others the body depends on.
Dr. William Albrecht, chairman of the soils department at the University of Missouri and one of the most important soil scientists of the twentieth century, spent his career documenting the relationship between soil mineral density and the health of everything grown in it. His collected writings, published as The Albrecht Papers in volumes from 1975 to 1992, make a sustained case that human health tracks directly with soil mineral content — and that the erosion of that content is an erosion of nutritional value we cannot see on the surface.
Continuous monoculture accelerates this depletion. Growing the same crop on the same land year after year pulls the same minerals from the soil repeatedly without replacing them. Add to this the loss of topsoil through erosion — the United States is estimated to have lost approximately half its original topsoil in the last 150 years — and the thinning of the soil's microbial life, which is what makes minerals bioavailable to plant roots in the first place, and you have a compounding problem that no amount of NPK fertilizer addresses.
Mayer's team names one more cause, and this one comes from the air. Rising carbon dioxide pushes plants to make more carbohydrate, which waters down everything else in the plant. A crop can grow faster in a richer atmosphere and still carry less of what we eat it for.
A plant can only take up what is there. If zinc is absent from the soil, the plant cannot manufacture it. That carrot in your bag grew. It just did not have the minerals to pass on.
Food Minerals vs. Water Minerals
There are two primary ways the body has historically received minerals: through food and through water. Both have been compromised in the modern world, though in different ways.
The food mineral story is what this article is about — depleted soils producing mineral-light food. The water mineral story is covered more fully in Hydration and Minerals: Why Water Alone Is Not Enough, but the short version is this: reverse osmosis, heavy filtration, and municipal water processing strip the dissolved minerals that natural spring and well water once carried reliably. Many people today drink mineral-free water without realizing it.
Together, these two losses create a gap. The body's requirement for minerals has not changed. The supply has.
The Case for Real Salt
Table salt is sodium chloride, refined and stripped of everything that was not sodium or chloride. It is the mineral equivalent of white flour — functional in a narrow sense, but a shadow of the original.
Real unrefined salt — Celtic sea salt being among the most studied and trusted forms — is a different substance. Harvested by hand from the coastal salt pans of Brittany, France, using methods that have not changed in centuries, Celtic gray salt retains its full complement of trace minerals. Its distinctive gray color comes from the clay of the harvest beds and is a sign of its mineral content, not a flaw. It contains magnesium, potassium, calcium, zinc, iron and dozens of trace elements in naturally balanced proportions. Its sodium content is lower than refined table salt, and its mineral profile is closer to blood plasma than any processed salt.
The distinction matters not just nutritionally but because of what real salt offers that supplements in capsule form do not: minerals in their natural ionic form, already dissolved and in proportion to each other, the way the body evolved to receive them.
One mineral needs sourcing on its own: iodine. Table salt is the one salt fortified with it. Where to get it, how much is enough and how much is too much are covered in When Minerals Run Low.
A Note on Quality and Heavy Metals
Not all sea salt is the same. The oceans carry pollution now, and some commercial sea salts — particularly those harvested from industrially affected coastal waters — have been found to contain measurable levels of microplastics and heavy metals including lead, cadmium, and arsenic. A 2018 study published in Environmental Science and Technology by Seung-Kyu Kim and colleagues found microplastics in 90 percent of sea salt brands tested across 21 countries.
This is not a reason to avoid sea salt — it is a reason to be selective about the source. Celtic sea salt from established traditional producers in Brittany is harvested from protected, monitored coastal waters and is routinely tested for heavy metal content. Redmond Real Salt, mined from an ancient seabed in Utah, is another well-regarded option from an uncontaminated inland source.
Himalayan pink salt, mined from ancient inland sea deposits, is also widely available — but not all Himalayan salt is equivalent. Quality varies significantly by origin, and some products sold as Himalayan salt have been found to contain measurable heavy metals including lead and cadmium. If you choose Himalayan salt, check the country of origin on the label. Salt from Pakistan — specifically from the Khewra mine region — is generally considered the more reliable source, as it comes from a well-established deposit with a longer testing history. Avoid products that do not list a country of origin.
What Supplementing Looks Like in Practice
Supplementing minerals does not have to be complicated. A few practical approaches:
Use real salt instead of table salt. This is the simplest daily step. Switching to Celtic gray salt or Redmond Real Salt means every time you season food, you are adding a small, natural dose of trace minerals rather than refined sodium alone. Unrefined salt is still sodium, so anyone with high blood pressure or kidney disease speaks with a doctor before raising it.
Consider a trace mineral supplement. Liquid trace mineral concentrates — typically derived from Great Salt Lake brine or similar ancient mineral-rich water sources, with sodium removed — offer a broad spectrum of trace elements in ionic form. A few drops in a glass of water daily is a low-effort, high-impact habit.
Prioritize magnesium. It is one of the most commonly deficient minerals in the modern diet and one of the most important. Magnesium glycinate is well absorbed and easy on digestion. Magnesium malate is useful for energy. Topical magnesium (magnesium chloride flakes dissolved in water and applied to skin) is an option for those who do not absorb oral supplements well.
Eat organic when it matters. Organic produce does not guarantee mineral density — soil quality varies — but organic certification requires longer rotation practices and prohibits many of the synthetic inputs that accelerate mineral depletion. It is a meaningful tilt in the right direction.
I put a pinch of Baja Gold sea salt in a glass of water each morning as part of my daily routine. The difference in my energy through the day has been real — and most noticeable in hot weather, when I used to feel more sluggish by afternoon. It is one of the simplest things I have done consistently for my body, and one that has stayed effortless. If you are going to start somewhere, this is the place.
The signs a body gives when a mineral runs short — mineral by mineral, and how you would know them — are the subject of Part 2, When Minerals Run Low.
What the soil gave and then lost we can replace — one mineral at a time.
Sources & Inspiration: Anne-Marie Mayer, Liesl Trenchard and Francis Rayns, “Historical Changes in the Mineral Content of Fruit and Vegetables in the UK from 1940 to 2019,” International Journal of Food Sciences and Nutrition, 2022. David Thomas, “A Study on the Mineral Depletion of the Foods Available to Us as a Nation over the Period 1940 to 1991,” Nutrition and Health, 2003. Donald R. Davis et al., “Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999,” Journal of the American College of Nutrition, 2004. William A. Albrecht, The Albrecht Papers, Acres U.S.A., 1975–1992. Seung-Kyu Kim et al., “Global Pattern of Microplastics in Commercial Food-Grade Salts,” Environmental Science & Technology, 2018.
This article is for informational and educational purposes only. If you live with high blood pressure or kidney disease, or take medicine for either, speak with your doctor before adding salt, potassium or any mineral supplement. Minerals interact with one another and with prescription medicine. Speak with a qualified healthcare provider before beginning a mineral supplement or making any change to your supplement routine or health plan.