Indicator Explainer
Retinol
The fat soluble vitamin retinol. Vitamin A binds to and activates retinoid receptors (RARs), thereby inducing cell differentiation and apoptosis of some cancer cell types and inhibiting carcinogenesis. Vitamin A plays an essential role in many physiologic processes, including proper functioning of the retina, growth and differentiation of target tissues, proper functioning of the reproductive organs, and modulation of immune function.
This page explains what the indicator is and how results are interpreted in general terms. Reference ranges depend on the laboratory, the method, and your own situation — no single “normal value” applies to everyone. This page is health information, not a diagnosis. For symptoms, treatment, or urgent concerns, contact a healthcare professional.
When it is tested
Source: National Cancer Institute, NCI Thesaurus 26.09d, C68302. NCI definition, reproduced without modification under CC BY 4.0. Source identity and definition checked automatically on 2026-10-19. No individual clinical interpretation or human reviewer is asserted.
Reading results
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also Known As
References
- NCI Thesaurus 26.09d — Retinol (C68302)
- Source: National Cancer Institute, NCI Thesaurus 26.09d, C68302. NCI definition, reproduced without modification under CC BY 4.0.
- Structural and biochemical basis for retinol-binding protein 4 antagonism by tinlarebant. — Br J Pharmacol, 2026-09-29 (PMID 42810809; literature)
- Radical cations vs. cations: a comparative study of retinyl cation and retinol radical cation. — Photochem Photobiol Sci, 2026-09-29 (PMID 42809211; literature)
- Downregulation of alcohol dehydrogenase family proteins suggests disrupted retinol metabolism in neonatal respiratory distress syndrome: an umbilical cord blood proteomics study. — Front Pediatr, 2026-09-29 (PMID 42871364; literature)
- Urinary retinol-binding protein 4 as a noninvasive indicator of tubular ferroptosis in diabetic kidney disease. — Free Radic Biol Med, 2026-09-28 (PMID 42805424; literature)
- ABO blood group-dependent association of serum retinol-binding protein 4 with eosinophilic inflammation and spirometric parameters in adults with asthma. — Monaldi Arch Chest Dis, 2026-10-16 (PMID 42886163; literature)
- Correction-free quantification of retinol in dried blood spots from children: agreement with plasma concentrations and plasma-based classification of vitamin A inadequacy. — J Nutr, 2026-10-26 (PMID 42933650; literature)
- Retinol Stimulates Growth Factor Production and Extracellular Matrix-Related Marker Levels in Human Dermal Fibroblasts. — Biomolecules, 2026-10-20 (PMID 42939784; literature)