How Mineral Deficiencies Can Lead to Fatigue and Brain Fog

Calories get the spotlight, but what runs your cells is minerals, and most of us aren’t getting enough. 

Illustration by The Epoch Times, Shutterstock

A person could have slept for eight hours, eaten well, yet still be reaching for their third coffee by noon because they still cannot quite get going. Before blaming their schedule or age, it may be worth asking a question, the answer to which is measured in milligrams.

Minerals are the hidden drivers of the body. They activate the enzymes that convert food into energy. They regulate cellular signaling, gene expression, and stress hormones.

For Caroline Alan, an author, self-described “Mineral Geek,” and cofounder of BEAM, a mineral supplement company, the gap between “doing everything right” and still feeling unwell became disruptive. About 10 years ago, while working a high-stress corporate job, she was dealing with worsening digestive issues, fatigue, and eventually insomnia, brain fog, recurrent sinus infections, and declining oral health. Despite meeting with multiple practitioners, she said she saw no lasting improvement and was eventually unable to continue working.

It wasn’t until she began taking mineral “replenishers” that things shifted. Over roughly eight months, she experienced a full resolution of symptoms, with measurable improvements observed by her doctors.

“My dentist was like, ‘Oh my God,’” Alan told The Epoch Times.

This experience led her to deeply investigate minerals and biology. What she found is not new information but is often overlooked: Minerals are the tiny hidden drivers of the body.

“If you have a [mineral] deficiency, things just don’t work. It’s like a motor. It’s like an engine. The actual engine is the minerals,” Bryan Quoc Le, who has a doctorate in food science and technology and is a food scientist and consultant, told The Epoch Times.

It’s not just a question of whether you are getting enough minerals, however, but also whether your cells are actually able to use them.

What Happens When Your Cells Run Low

To understand the problem, you have to look at the mitochondria—the powerhouses of the cell that convert nutrients from food into ATP, the molecule that serves as the body’s primary form of usable energy. This conversion is a multistep process that depends heavily on enzymes, most of which require minerals to function. Many minerals act as cofactors—helpers that allow enzymes to switch on and carry out important functions in the body.

“Minerals have a huge effect on enzymes,“ Dr. Aaron Erez, a functional medicine physician, told The Epoch Times. ”At the core of it, these enzymes just simply don’t work if you’re deficient in them.”

When mineral availability is low, mitochondrial efficiency drops. That inefficiency does not always show up as a single dramatic symptom. Instead, it tends to manifest across multiple systems at once: persistent fatigue that doesn’t resolve with rest; brain fog and difficulty concentrating, poor sleep despite feeling exhausted, a sluggish immune system prone to recurrent infections, muscle cramps, mood changes, and heightened stress sensitivity.

None of these symptoms is specific to mineral status, but some clinicians who work in functional medicine recognize this cluster in patients with below-par nutrient intake or absorption.

A 2020 review published in Nutrients described mitochondria as more than just energy producers. They are also involved in how cells communicate and function. The authors also noted that mitochondrial function depends on vitamins and minerals that work with enzymes to carry out their jobs. Diets that are rich in ultra-processed foods and relatively low in whole foods may therefore compound this problem by crowding out foods that provide essential nutrients precisely when the body needs them most.

The Modern Mineral Gap

Even if you eat a diet full of fruits and vegetables, you may be getting fewer minerals than you think.

A 2024 review published in Foods argued that the nutrient density of modern crops has declined significantly, largely because our agricultural system prioritizes volume over nutrition. Aggressive high-yield crop breeding and intensive industrial practices were found to have collectively degraded soil health and diminished the mineral content of modern fruits and vegetables.

A 2021 research article tracking mineral content of fruits and vegetables in the UK from 1940 to 2019 found substantial drops in sodium, iron, copper, and magnesium over that period.

That’s because industrial agriculture only adds fertilizers that make crops grow. It does not replenish the soil’s wider mix of minerals; it only extracts them.

“You grow 100 million acres of one crop, and it extracts, and it extracts, and it extracts,” Le said. “You can’t pull things out and hope that they'll just spontaneously regenerate.”

Consumer preference for processed foods has made the problem worse.

“All the good stuff, all the minerals, are found in the husk that we strip away because we love the taste of white bread,” he said.

Which Minerals Are Most at Risk?

While mineral needs vary from person to person, some deficiencies are more common than others.

“If I had to pick three or four, it’s probably iron, magnesium, zinc, and copper,” said Erez, describing the deficiencies that he sees most often in patients.

He noted that magnesium, in particular, has become an across-the-board issue for people. It plays a central role in more than 300 functions, including energy metabolism, muscle function, and nervous system regulation. Chronic stress accelerates magnesium depletion because cortisol causes the body to excrete more magnesium.

“It’s because people are under chronic stress, and cortisol, which is a stress hormone, makes you go through your magnesium much quicker,” Erez said.

Zinc plays a key role in immune system function and enzyme activity, while copper is involved in energy production and iron metabolism. Iron and magnesium also help mitochondria produce energy for the body. Imbalances in these minerals can contribute to symptoms such as fatigue, immune dysfunction, and impaired tissue repair.

No two people’s needs are alike, and knowing where to start is also key.

“I really would encourage people to go out and get a functional health test and just get your data,” said Erez, meaning a comprehensive set of blood tests and specialty labs to assess nutrient status.

How to Close the Gap

Getting enough minerals is not just about what you eat. Your body also has to be able to absorb and use them. Because minerals work together, variety across a range of whole food sources provides a broader spectrum.

Diet

Le recommends eating more fruits and vegetables, “eating the rainbow,” and prioritizing local, seasonal produce, to help cover your mineral bases. Local produce that is in season is often harvested closer to its peak growing conditions, Le noted.

“That’s the prime time where that fruit and vegetable is sort of maximizing its mineral intake,” he said.

Le also pointed out that how food is prepared can also influence how accessible nutrients are to the body.

Eating fermented foods is an underused way to make minerals more available. The fermentation process helps break down the plant structures that can make minerals harder for the body to access and absorb.

“Your body’s actually really terrible at breaking down plant matter and absorbing minerals,” Le said. “But fermented foods are able to break those down and absorb them into their system, and then our bodies will eat those. So it kind of completes the cycle.”

Another often-overlooked source of minerals is the peels and skins of produce, where they tend to accumulate.

“The skin of a potato is very rich in potassium,” Le said.

He recommends eating peels when possible, ideally from organic produce, since pesticides can also concentrate in the outer layers.

Absorption

It does not matter how many minerals are in your food if you cannot absorb them. When it comes to this, stomach acid is a key player. It activates the digestive enzymes that break down food and release minerals for absorption. When acid levels are low, that process becomes less effective.

This is particularly relevant for people taking proton pump inhibitors (PPIs), a widely used class of acid-reducing drugs.

“PPIs actually diminish the acid so much that you’re not absorbing those minerals that you should be,” Erez said.

He also noted that stomach acid naturally declines with age, which partly explains why mineral deficiencies become more common in older adults. For that reason, he recommends testing to identify potential nutrient gaps.

Another major factor that can undermine mineral absorption is inflammation.

“It’s staggering how much it impacts how much you can absorb minerals,” Le said.

When intestinal tissue is inflamed, the body prioritizes repair over nutrient uptake.

“If your intestinal cells and tissues are struggling, they have no interest in absorbing more things,” he said.

Le suggests  removing pro-inflammatory foods such as ultra-processed products, as well as alcohol.

“Alcohol does not work with mineral intake,“ he said. ”If you drink alcohol, the minerals just get dumped. It’s really stressful for the liver and the stomach to do both of those jobs.”

Lifestyle factors such as stress management and sleep hygiene also help keep inflammation in check.

Sometimes the body can only take up so much of one nutrient when high amounts of another nutrient are also present and competing for absorption. This is not a problem when you are getting your minerals from a whole-food diet, but it can become a significant issue with high-dose supplements.

Supplementation

Taking high-dose isolated supplements without knowing your baseline status can create imbalances that are as problematic as the deficiencies they were meant to correct.

“The body is all about balance,“ Alan said. ”It’s like a forest. If you put a wheelbarrow of magnesium on a forest floor, those plants aren’t going to thrive.”

A category gaining attention in this space is fulvic and humic substances, compounds derived from decomposed organic matter in soil. Because they are hard to get in substantial amounts from food, they are usually sold as liquid drops, powders, or capsules. These supplements are the mineral replenishers that Alan credits with restoring her health.

Research published in 2025 in Antioxidants suggests that humic substances may enhance nutrient uptake in plants, but evidence in humans remains limited.

For now, your best bet is prioritizing a strong nutritional foundation, paying attention to gut health and lifestyle factors that influence absorption, and using supplementation only when needed or guided by a clinician.

The core of cellular health remains rooted in what we put on our plates. If minerals are the engine of our body, then nutrient-dense food is the premium-grade fuel.

As Le put it: “A farmers market is a good first step.”