{"id":"complement-c3","name":"Complement C3","shortName":"C3","aliases":["C3","C3 Complement","Complement C3, Serum","C3, Quantitative","C3c","Complemento C3","Complement Component 3","Complement C3, Quant","Complement C3, S","Serum C3","C3 Level","Third Component of Complement","C3 Complement, Serum","Complement C3 (C3c)"],"abbreviations":["C3","C3c"],"loinc":[{"code":"4485-9","primary":true},{"code":"4491-7","primary":false}],"specimen":"serum-or-plasma","units":[{"ucum":"mg/dL","display":"mg/dL"},{"ucum":"g/L","display":"g/L"},{"ucum":"mg/L","display":"mg/L"}],"referenceRanges":[{"population":"18+","low":90,"high":180,"unit":"mg/dL","unitDisplay":"mg/dL","note":"ARUP Laboratories interval for ages 18 and older (immunoturbidimetry). Mayo Clinic Laboratories prints 75 to 175 mg/dL for its nephelometry assay. Neither lab splits by sex. Compare with the range on your own report.","sources":[{"title":"Complement Component 3 (test 0050150)","url":"https://ltd.aruplab.com/Tests/Pub/0050150","publisher":"ARUP Laboratories"},{"title":"Complement C3 and C4 with Anti-C1q Antibodies, Serum (test C341Q)","url":"https://www.testcatalog.org/show/C341Q","publisher":"Mayo Clinic Laboratories (Extended Catalog)"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The most abundant complement protein in your blood. Complement is part of the immune system, and C3 sits at its center.","url":"https://bloodtesttracker.com/markers/complement-c3","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}