Biotin Supplementation and Ferritin Concentrations
Biotin supplementation does not consistently change measured ferritin concentrations in controlled supplementation studies. [1]
Biotin supplementation can cause clinically relevant laboratory assay interference for some ferritin immunoassays in a way that can produce misleading ferritin results even when true iron stores have not changed. [2]
Evidence From Supplementation Trials
A 30-day randomized intervention comparing organically sourced versus synthetically sourced multivitamin formulations found no changes in iron-related biomarkers, including ferritin concentrations, during the 30-day period. [1]
In that same trial, a short-term (2-hour) ingestion protocol produced increases in ferritin concentrations for both supplement types, without demonstrating a sustained ferritin change over 30 days. [1]
Mechanism of Potential Apparent Ferritin Changes
Many clinical immunoassays rely on biotin–streptavidin binding. [2]
Excess supplemental biotin can interfere with those biotinylated assay systems and produce false ferritin values. [2]
Laboratory Testing Implications
Biotin-associated interference has been observed for ferritin among other analytes in biotinylated immunoassay formats. [2]
Biotin-associated interference occurred in a substantial fraction of biotinylated assays in healthy adults taking 10 mg/day biotin for 7 days, supporting the possibility of misleading ferritin results depending on the specific assay platform used. [2]
Practical Clinical Approach
Ferritin results obtained while taking supplemental biotin should be interpreted with caution because assay interference can lead to non-reflective ferritin measurements. [2]
Timing of blood draws relative to biotin dosing and use of non-biotinylated assay methods can reduce the risk of spurious ferritin results, which is directly linked to assay design rather than iron physiology. [2]
Bottom Line
Biotin supplementation has limited evidence for producing true ferritin changes over longer supplementation periods. [1]
The more clinically significant concern is assay interference that can make ferritin appear altered without a real change in iron stores. [2]