Potassium

Potassium is an essential mineral and electrolyte that helps your nerves fire, your muscles contract, and your heart keep a steady rhythm. A routine blood test (serum potassium) measures the amount of potassium circulating in your blood at that moment. Most potassium lives inside your cells, so blood levels can shift with meals, exercise, and how the sample is taken. Tracking potassium over time helps you see how your food choices, hydration, training, and salt use are working for you. (1)

For generally healthy people, staying in the normal range supports smooth muscle and nerve function, stable energy, and heart rhythm.

• Low potassium can show up as muscle cramps, fatigue, or palpitations. It is often linked to losses from sweat or the gut, low magnesium, or transient shifts after a big insulin spike from a high-carb meal. (2) Cleveland Clinic
  

• High potassium may be silent but, if marked, can disturb the heart’s electrical system. Very high levels need urgent attention. (1) Cleveland Clinic
  

Diet matters too. Eating more potassium-rich whole foods and less sodium is consistently linked with lower blood pressure and reduced cardiovascular risk over the long term. The World Health Organization recommends adults aim for at least 90 mmol per day, about 3510 mg, mostly from food. (3)

Think of potassium as a daily habit, not a one-off fix. These simple, science-backed tweaks fit well for healthy people using testing to optimise and track progress.

1) Make your plate potassium-forward, most days.
Build meals around vegetables, fruit, legumes, potatoes or sweet potatoes, dairy or yogurt, and fish. Processed foods tend to be higher in sodium and lower in potassium, while minimally processed foods flip that balance. Over months, this pattern helps blood pressure and supports nerve and muscle function. (3) World Health Organization

2) Try a smart salt swap at home.
Replacing some table salt with a potassium-enriched salt substitute (for cooking and finishing) is a practical “biohack” with measurable effects. Across 21 trials and ~32,000 people, salt substitutes lowered systolic blood pressure by about 4.6 mmHg and diastolic by about 1.6 mmHg on average. This adds up when maintained over time. Suitable for many healthy adults who are not on medicine that interfere with potassium. (4)

3) Train and refuel with potassium in mind.
Regular exercise is great. If you sweat heavily or do long endurance sessions, include potassium-rich foods in recovery (think potatoes, beans, leafy greens, yogurt, fruit) and keep up fluids. This helps maintain stable readings across training blocks you can see reflected in your yearly panel. (3) 

4) Support the cofactors.
Low magnesium makes it harder for your body to hold onto potassium. Include magnesium-rich foods like nuts, seeds, legumes, and greens alongside your potassium hits to keep levels steady over time. (2)

For the most comparable results over months, try to be consistent: similar meal timing before the test, avoid all-out workouts just prior, and arrive well-hydrated. (2)

Reference ranges 

• Optimal: 3.5–5.0 mmol/L

• Mildly low: 3.0–3.4 mmol/L 

• Very low: <3.0 mmol/L 

• Mildly elevated: 5.1–5.5 mmol/L 

• Very high: ≥6.5 mmol/L

1. Hyperkalemia (High Potassium). Cleveland Clinic, 2023. Available from: https://my.clevelandclinic.org/health/diseases/15184-hyperkalemia-high-blood-potassium

2. Hypokalemia (Low Potassium). Cleveland Clinic, 2022. Available from: https://my.clevelandclinic.org/health/diseases/17740-low-potassium-levels-in-your-blood-hypokalemia

3. Increasing potassium intake to reduce blood pressure and risk of cardiovascular diseases in adults. World Health Organization eLENA, 2023. Available from: https://www.who.int/tools/elena/interventions/potassium-cvd-adults

4. Effects of salt substitutes on clinical outcomes: a systematic review and meta-analysis. Heart (BMJ), 2022. Available from:https://heart.bmj.com/content/108/20/1608