Micronutrients & Electrolytes

Meta-analysis finding iron supplementation significantly improved VO2max and endurance performance in iron-deficient (non-anemic) women. Supports iron micronutrient tracking for aerobic capacity.

Review demonstrating that optimal vitamin D status (≥100 nmol/L) is associated with improved skeletal muscle function, aerobic capacity, force/power production, faster recovery, and higher testosterone levels in athletes.

Narrative review establishing that magnesium is a cofactor in >300 enzymatic reactions including ATP synthesis, that athletes commonly have lower serum magnesium, and that supplementation may improve energy metabolism and physical performance.

Found that magnesium status positively correlates with testosterone levels, and combined magnesium supplementation + exercise produced higher testosterone and greater isokinetic strength gains than exercise alone.

Systematic review finding vitamin D supplementation most strongly benefited aerobic capacity (VO2max) and upper body strength measures in athletes, while also showing a possible association between serum 25(OH)D and testosterone levels.

The reference values shown for the 20 micronutrients we track are Dietary Reference Intakes (DRIs), developed by expert committees of the U.S. National Academies of Sciences, Engineering, and Medicine (formerly the Institute of Medicine). DRIs are the consensus reference values used in U.S. and Canadian nutrition policy.

Reference values vary by age and sex; individual needs may differ. Pregnancy, lactation, and certain medical conditions are not currently modeled. Consult a healthcare provider for personalized guidance.

Comprehensive meta-analysis of RCTs finding calcium supplementation produces small (1–2%) non-progressive increases in BMD that are unlikely to reduce fracture risk in isolation — establishing that calcium works best in combination with vitamin D and physical activity, validating the app's integrated tracking approach rather than calcium-only guidance.

Meta-analysis of combined calcium + vitamin D supplementation finding a 15% reduction in total fractures and 30% reduction in hip fractures across mixed adult populations — validating that adequate calcium intake paired with vitamin D (both tracked in the app) is the evidence-based approach for bone health maintenance.

Cross-sectional study in young athletes establishing that dietary calcium plays a direct role in muscle contraction via Ca²⁺ ion signalling, energy metabolism, bone development, and cardiovascular function — validating calcium as a performance-relevant micronutrient for active users, not just a bone health marker.

WHO-commissioned systematic review and meta-analysis of RCTs and cohort studies finding increased potassium intake reduced systolic blood pressure by 3.49 mmHg and diastolic by 1.96 mmHg in adults with hypertension, plus associations with reduced stroke and CVD risk — establishing potassium tracking as a key cardiovascular health micronutrient.

Summary of 32 meta-analyses covering sodium, potassium, calcium, and magnesium's effects on blood pressure — finding systolic BP reductions of 3.5–9.5 mmHg for potassium and 0.7–8.9 mmHg for sodium reduction, validating the combined electrolyte tracking approach in RobustHealth's micronutrient module.

Comprehensive systematic review finding that sodium is the primary electrolyte lost in sweat, that both high and low sodium intake carry performance and health risks for athletes, and that individualized sodium replacement strategies are necessary to prevent both hyponatremia and performance decrements.

Dose-response meta-analysis establishing a graded, nonlinear relationship between potassium intake and blood pressure reduction — with the greatest benefit seen in hypertensive individuals — providing evidence-based targets for potassium intake recommendations within the app's micronutrient goals.

Systematic review of 21 RCTs finding inconsistent evidence that vitamin C or E supplementation reduces exercise-induced muscle damage markers (CK, DOMS), while noting that high-dose supplementation may blunt training adaptations by reducing beneficial reactive oxygen species signalling — validating a nuanced approach to antioxidant tracking in active users.

Meta-analysis of RCTs finding vitamin C supplementation significantly reduced oxidative stress markers post-exercise but showed inconsistent effects on inflammatory markers, DOMS, and strength recovery — validating vitamin C tracking as relevant for recovery monitoring while cautioning against megadosing.

Most recent PRISMA-registered meta-analysis of 12 RCTs finding no statistically significant effects of vitamin C supplementation on IL-6 or MDA post-exercise, while CRP showed a trend toward reduction — the most current evidence base informing the app's evidence-graded vitamin C recommendations.

Narrative review establishing that thiamine (B1), riboflavin (B2), and niacin (B3) are essential coenzymes in aerobic and anaerobic energy metabolism pathways, and that exercise increases urinary loss of B6 and riboflavin — validating why the app tracks B vitamins as exercise-relevant micronutrients rather than general population metrics.

Crossover RCT in 32 adults finding 28-day B-complex supplementation (B1, B2, B6, B12) significantly reduced perceived fatigue and improved submaximal exercise performance compared to placebo — providing direct RCT evidence for B-vitamin tracking in active users.

Foundational review establishing that moderate exercise increases riboflavin requirements and B6 excretion, particularly in individuals already consuming marginal intakes — validating that athletes and active users have higher B-vitamin requirements than sedentary reference intakes suggest.

NHANES data show that over 50% of US adults consume less than the Estimated Average Requirement for magnesium, with the gap widest in older adults, African Americans, and people with type 2 diabetes. This review argues the health consequences are systematically underestimated because serum magnesium — the standard clinical test — is a poor biomarker of body magnesium status: less than 1% of total body magnesium is extracellular, meaning serum levels remain normal until body stores are severely depleted. Subclinical magnesium deficiency is linked to hypertension, cardiovascular disease, type 2 diabetes, osteoporosis, and migraine — making it a silent population-level health problem.

This review makes the case that subclinical magnesium deficiency is a leading driver of cardiovascular disease through multiple mechanisms: magnesium acts as a natural calcium channel blocker, and deficiency promotes arterial calcification, coronary vasospasm, cardiac arrhythmia, and platelet aggregation. Additionally, modern food processing removes magnesium — refined grains lose up to 80% of their magnesium content versus whole grain equivalents, and soft drinks and high sugar diets increase urinary magnesium excretion. The authors estimate that chronic low-grade magnesium deficiency may explain a substantial portion of the CVD burden in Western societies.

Magnesium is a cofactor in over 300 enzymatic reactions including all ATP-generating reactions and insulin receptor signalling; inadequate magnesium impairs insulin-receptor tyrosine kinase activity and post-receptor signalling, directly causing insulin resistance. Epidemiological studies consistently show that higher dietary magnesium intake is associated with a 10–33% lower risk of type 2 diabetes, with each 100 mg/day increment in intake reducing risk by approximately 15%. This metabolic mechanism is distinct from the cardiovascular pathways, establishing magnesium deficiency as a modifiable risk factor for both insulin resistance and cardiovascular disease — particularly relevant to users tracking macros and body composition goals.