Electrolytes — Not Just
Salt and Water

Minerals came first. The word vitamin — coined by Casimir Funk in 1912 from vita (life) and amine (nitrogen-containing compound) — was actually a misnomer from the start. Most vitamins contain no amine group at all. But the naming stuck, and vitamins became the dominant framework for thinking about micronutrient supplementation throughout the twentieth century.

Minerals never got the same marketing moment. They sit in the background of most supplement conversations, listed at the bottom of the nutrition panel in milligrams nobody knows whether to be impressed by. And then sports science renamed the most important ones electrolytes — from the Greek elektron (amber, the first observed source of static charge) and lytos (able to be loosened) — and suddenly they had a product category, a neon-coloured drinks aisle, and an association with athletic performance that both elevated and distorted the clinical picture.

The clinical picture is this: electrolytes are charged mineral ions that conduct electricity in solution. Every biological process that involves electrical signalling — nerve conduction, muscle contraction, cardiac rhythm, gut motility, adrenal hormone release, nutrient transport across cell membranes — depends on the precise movement of these ions. You are not simply "staying hydrated." You are maintaining the electrochemical gradients that make life possible.

The sodium-potassium pump — why it matters for everything

The Na⁺/K⁺-ATPase pump is one of the most important proteins in the human body. It sits in the membrane of virtually every cell and uses one molecule of ATP to move three sodium ions out of the cell and two potassium ions in. This happens millions of times per second across trillions of cells simultaneously.

The reason this matters clinically is that the pump does not just create electrical excitability. It drives the co-transport mechanisms that absorb glucose and amino acids across the gut wall. Without the sodium gradient, glucose cannot be absorbed. This is the mechanism behind oral rehydration therapy — the glucose in oral rehydration solution is not for energy, it is to drive sodium absorption across a damaged intestinal epithelium. Sodium comes in, glucose comes with it.

The pump also accounts for a significant proportion of resting metabolic rate. Thyroid hormone, in part, acts by upregulating the Na⁺/K⁺-ATPase — which is why hypothyroidism produces cold intolerance, slow gut motility, and fatigue. The pump slows. The gradients flatten. The downstream functions all deteriorate.

The major electrolytes — and why each has a specific clinical context

The commercial electrolyte market treats all electrolytes as interchangeable hydration ingredients. Clinically they are not. Each has a distinct physiological role, a distinct set of clinical presentations when depleted or excess, and a distinct set of conditions under which supplementation is appropriate or counterproductive.

When you need more sodium — and when you don't

The reflex assumption in most electrolyte conversations is that sodium is the enemy — the thing that raises blood pressure and causes fluid retention. This is a population-level public health message that obscures significant individual variation and is actively wrong for a clinically important subset of people.

Sodium depletion is the dominant electrolyte picture in HPA axis exhaustion — the Stage 3 depleted cortisol pattern described in the Resilient Stress System. Aldosterone, produced by the adrenal cortex, is the hormone that instructs the kidney to retain sodium. When adrenal output is chronically suppressed, aldosterone falls. The kidney stops retaining sodium efficiently. Sodium — and the water that follows it osmotically — is lost in urine. The person feels dizzy on standing, craves salt, has low blood pressure, and feels paradoxically worse after sweating.

For this person, increasing dietary sodium with a high-quality unrefined salt — Celtic grey salt, Himalayan pink salt, or similar — is not a cardiovascular risk. It is adrenal support. The commercial electrolyte product they are taking, however, may be predominantly sodium chloride without the trace mineral context that unrefined salt provides, or may be predominantly potassium-based because the manufacturer is targeting athletic performance rather than adrenal support.

When you need more potassium — and why most people don't supplement it correctly

Potassium is the dominant intracellular cation. The cell works hard to keep potassium inside and sodium outside. When that gradient flattens — from poor dietary intake, diuretic use, excessive sweating, diarrhoea, or chronic stress — the consequences are felt in the muscles first (cramps, weakness), then in the gut (constipation, slow motility), then in the cardiovascular system (arrhythmia, blood pressure dysregulation).

The clinical problem with potassium supplementation is threefold. First, regulatory limits mean that most over-the-counter potassium supplements contain only 99mg per tablet — a fraction of the 3,500–4,700mg daily requirement. A meaningful potassium intervention through supplementation alone is difficult without prescription-strength formulations. Food sources — avocado, banana, potato skin, leafy greens, legumes — are the practical route for most people.

Second, potassium supplementation without adequate magnesium is often ineffective. Magnesium is required for the Na⁺/K⁺-ATPase pump to function — without it, the pump cannot move potassium into cells even when potassium is available. Correcting potassium without first establishing magnesium adequacy is frequently why "I take potassium and my cramps don't improve" is such a common complaint.

Third — and this is the most clinically important point — potassium supplementation in the context of kidney disease or with ACE inhibitors, ARBs, or potassium-sparing diuretics can cause hyperkalaemia. This is not a theoretical risk. Elevated serum potassium disrupts cardiac conduction and is a medical emergency. Anyone on these medications or with compromised kidney function should not supplement potassium without medical oversight regardless of symptoms.

The four clinical scenarios — and what each actually needs

The morning routine — what actually works and why

The glass of warm water with lemon or lime first thing in the morning has become a wellness cliché to the point where its clinical rationale is rarely explained. The rationale is worth understanding because it is genuinely useful — and worth doing correctly.

Lemon and lime juice are acidic in the glass — pH around 2–3. But their mineral ash (what remains after metabolism) is alkaline. The organic acids — citric, malic, ascorbic — are metabolised and their anionic conjugate bases are excreted, taking hydrogen ions with them. The net effect on urine pH is alkalising. This is the basis of the "alkaline water" claim, and it is real, though modest.

The more immediately practical effects are mechanical and biochemical. Water first thing in the morning after eight hours without intake stimulates the gastrocolic reflex — the peristaltic wave that initiates bowel movement in response to stomach distension. Adding lemon increases gastric acid production via vagal stimulation and the mild irritant effect of citric acid on the gastric mucosa — useful for people who are hypochlorhydric (low stomach acid). The effect on bowel regularity is real and has nothing to do with "detoxification" — it is straightforward mechanical and acid-secretion stimulation.

Adding a pinch of unrefined salt to this morning drink provides chloride for stomach acid production, trace minerals, and a small sodium stimulus for aldosterone-mediated fluid regulation. Adding raw honey provides a small amount of glucose and fructose — the glucose directly stimulates sodium-glucose co-transport in the gut, which is the same mechanism as oral rehydration therapy. This is not a magic drink. It is a physiologically sensible way to rehydrate after overnight fasting, support morning digestive readiness, and provide a modest electrolyte stimulus to the adrenal-kidney axis at the time of day when cortisol and aldosterone are naturally at their highest.

Epsom salts, bowel frequency, and what "cleansing" actually means

Magnesium sulphate — Epsom salt — works as a laxative through osmotic action. It draws water into the intestinal lumen, increasing stool water content and stimulating peristalsis. At low doses dissolved in a bath, it provides transdermal magnesium absorption without the osmotic gut effect. At higher oral doses, it produces loose stools — which is either the desired effect or an adverse effect depending on why you are using it.

The "bowel cleanse" or "detox" framing around Epsom salts and other osmotic laxatives is largely misused language. The gut is not a drain that accumulates toxic sludge requiring periodic flushing. What regular bowel movement actually achieves is the timely excretion of bile acids, oestrogen conjugates, and other hepatically processed compounds before they are reabsorbed in the distal colon. Constipation — transit time over 72 hours — allows more time for bacterial beta-glucuronidase to deconjugate oestrogen metabolites, allowing them to re-enter circulation. This is clinically relevant in oestrogen dominance, PCOS, and some hormonal cancer risk contexts.

So "keeping regular" does have genuine clinical value — but the mechanism is not toxin removal, it is limiting recirculation of compounds the liver has already processed and packaged for excretion. Magnesium — in the citrate form, not the sulphate — is the most clinically appropriate intervention for chronic constipation because it addresses the underlying magnesium-dependent gut motility issue rather than simply forcing an osmotic event.

Coconut water — useful, but not magic

Coconut water provides approximately 600mg of potassium per 250ml serving, 45mg of sodium, 60mg of magnesium, and small amounts of calcium and phosphorus. It is a reasonable natural electrolyte drink for mild rehydration and provides a better potassium-to-sodium ratio than most commercial sports drinks. It is also relatively high in natural sugar — around 10–12g per 250ml — which is relevant for anyone managing blood sugar.

Its clinical usefulness is genuine but specific. For someone with a potassium-dominant need, post-exercise depletion, or mild diarrhoea-related fluid loss, coconut water is a sensible choice. For someone with adrenal exhaustion and sodium depletion, the potassium-heavy ratio may worsen the picture — sodium-depleted individuals need more sodium, not more potassium competing with it.

What commercial electrolyte products get wrong

Most commercial electrolyte products — from supermarket sachets to premium powders — are formulated for one or more of three purposes: athletic performance, hangover recovery, or general "hydration." None of these is the same as clinical electrolyte correction. The limitations are consistent:

• Sodium-heavy formulations appropriate for sweating athletes are not appropriate for hypertensive individuals or those with kidney compromise
• Potassium-light formulations (constrained by regulatory limits) cannot meaningfully address potassium depletion
• No magnesium in many products — the most commonly deficient electrolyte in the UK population
• Artificial sweeteners, colours, and flavours in low-end products that are counterproductive for gut-sensitive individuals
• No clinical differentiation — the same product is marketed for the person with low blood pressure and the person with high blood pressure

The better approach: establish which electrolyte picture you are actually dealing with through blood chemistry, then use the appropriate targeted intervention rather than a generic product. A comprehensive blood chemistry panel gives you sodium, potassium, chloride, bicarbonate, calcium, and phosphate in one draw. Combined with RBC magnesium and kidney function markers, you have a complete electrolyte picture that tells you exactly which intervention is appropriate — and which is not.