Methodology
How this reference was compiled.
Evidence Tiers
- Tier A (Strong): Multiple RCTs, meta-analyses, systematic reviews, large observational studies (n>1000)
- Tier B (Moderate): Single RCTs, cohort studies, smaller observational studies
- Tier C (Preliminary): Pilot studies, case series, mechanistic evidence
- Tier D (Emerging): Theoretical, anecdotal, expert opinion
Sources
- PubMed / MEDLINE — peer-reviewed medical literature
- Cochrane Reviews — systematic reviews and meta-analyses
- Clinical guidelines — specialty society recommendations
- UK Biobank — large-scale population health data
- DOIs provided for verification where available
Optimal vs Normal Ranges
Standard lab "normal" ranges indicate absence of disease. Cognitive optimal ranges indicate levels associated with best brain function. For example:
- Ferritin: Normal >12 ng/mL → Optimal 50-150 ng/mL
- B12: Normal >200 pg/mL → Optimal >500 pg/mL
- hs-CRP: Normal <3.0 mg/L → Optimal <1.0 mg/L
Limitations
- Not all interventions have robust RCT evidence
- Individual response varies
- This is educational information, not medical advice
- Always consult with a qualified healthcare professional