Sodium citrate at 500 mg/kg body mass in capsule form reliably induces blood alkalosis & is most beneficial for short-duration, very high-intensity exercise; only 25% of observations showed significant performance improvements in high-intensity intermittent exercise, & gastrointestinal symptoms are a key limiting factor.

Sodium citrate ingestion significantly increased time to exhaustion during supramaximal cycling exercise versus placebo, associated with reduced intramuscular acidosis & improved metabolic performance.

Potassium is actively redistributed between skeletal muscle & plasma during high-intensity exercise; severe reduction of the trans-sarcolemmal K+ gradient contributes to muscle & whole-body fatigue. Maintaining adequate potassium status supports normal neuromuscular function & exercise capacity.

Increased potassium intake reduced blood pressure in people with hypertension (systolic −3.49 mmHg, diastolic −1.96 mmHg); associated with 24% lower risk of stroke (RR 0.76, 95% CI 0.66–0.89) with no adverse effect on blood lipids or renal function.

Vitamin D insufficiency is prevalent among athletes, particularly indoor athletes & those in northern latitudes in winter. Insufficiency is associated with reduced muscle strength, power, & endurance; supplementation of 2,000–6,000 IU/day recommended to maintain 25(OH)D >40 ng/mL.

Vitamin D at 700–800 IU/day reduced hip fracture risk by 26% (RR 0.74) & any nonvertebral fracture by 23% (RR 0.77); no significant benefit was observed at 400 IU/day.

Vitamin D supplementation reduced risk of acute respiratory tract infection (adjusted OR 0.88, 95% CI 0.81–0.96); greatest benefit in those with baseline deficiency (<25 nmol/L) & those receiving daily or weekly dosing rather than bolus doses.