Medical Sources & References

Proto's biomarker reference ranges, verdicts, and protocol logic draw on the clinical and public-health sources below. Reference ranges shown in Proto also reflect the ranges printed on your own lab report (Quest Diagnostics, Function Health, or your health system via MyChart).

Last reviewed: September 3, 2026

Metabolic

Glucose Blood Glucose Test — MedlinePlus, National Library of Medicine
Hemoglobin A1c Hemoglobin A1c (HbA1c) Test — MedlinePlus, National Library of Medicine
Insulin Insulin in Blood — MedlinePlus, National Library of Medicine
Glycemic thresholds Standards of Care in Diabetes — 2025 — American Diabetes Association, Diabetes Care

Lipids & Cardiovascular

Total Cholesterol, LDL, HDL Cholesterol Levels — MedlinePlus, National Library of Medicine
Triglycerides Triglycerides Test — MedlinePlus, National Library of Medicine
Apolipoprotein B Apolipoprotein B (ApoB) Test — Cleveland Clinic
Lipoprotein(a) Lipoprotein (a) Blood Test — MedlinePlus, National Library of Medicine
Lipid management thresholds 2018 AHA/ACC Guideline on the Management of Blood Cholesterol — Circulation, American Heart Association
hs-CRP C-Reactive Protein (CRP) Test — MedlinePlus, National Library of Medicine
Homocysteine Homocysteine Test — MedlinePlus, National Library of Medicine

Vitamins & Minerals

Vitamin D Vitamin D — Fact Sheet for Health Professionals — NIH Office of Dietary Supplements
Vitamin D Test — MedlinePlus
Vitamin B12 Vitamin B12 — Fact Sheet for Health Professionals — NIH Office of Dietary Supplements
Vitamin B Test — MedlinePlus
Magnesium Magnesium — Fact Sheet for Health Professionals — NIH Office of Dietary Supplements
Magnesium Blood Test — MedlinePlus
Omega-3 Fatty Acids Omega-3 Fatty Acids — Fact Sheet for Health Professionals — NIH Office of Dietary Supplements
Iron, Ferritin, TIBC Iron — Fact Sheet for Health Professionals — NIH Office of Dietary Supplements
Ferritin Blood Test — MedlinePlus · Iron Tests — MedlinePlus

Hormones & Thyroid

TSH TSH (Thyroid-Stimulating Hormone) Test — MedlinePlus, National Library of Medicine
Testosterone Testosterone Levels Test — MedlinePlus, National Library of Medicine
Estradiol Estrogen Levels Test — MedlinePlus, National Library of Medicine
Cortisol Cortisol Test — MedlinePlus, National Library of Medicine
DHEA-S DHEA Sulfate Test — MedlinePlus, National Library of Medicine

Kidney, Liver & Blood

Creatinine & eGFR Creatinine Test — MedlinePlus · Estimating GFR — NIDDK, National Institutes of Health
Uric Acid Uric Acid Test — MedlinePlus, National Library of Medicine
ALT ALT Blood Test — MedlinePlus, National Library of Medicine
AST AST Test — MedlinePlus, National Library of Medicine
Complete Blood Count (Hemoglobin, WBC, RBC, Platelets) Complete Blood Count (CBC) — MedlinePlus, National Library of Medicine

Wearable & Activity Metrics

Resting Heart Rate & HRV All About Heart Rate (Pulse) — American Heart Association
Sleep Duration About Sleep — Centers for Disease Control and Prevention

Data Standards

Biomarker coding LOINC — Logical Observation Identifiers Names and Codes — Regenstrief Institute

Proto is not a medical device and does not provide medical advice. Verdicts and protocols are informational rankings computed from your own lab values against the published reference sources above. Always consult your clinician before making changes to diet, supplements, or medications, and rely on the reference range printed on your lab report as issued by your laboratory. Questions: [email protected]