tuneTypical Dose
Obtained via vitamin B12 only
Mineral
Cobalt
Cobalt (Co, element 27)
Evidence TierDWADA PROHIBITED
watchEffect Window
N/A for standalone supplementation.
lockCompliance
WADA PROHIBITED
Overview
Clinical Summary
Cobalt is a trace element primarily relevant as part of vitamin B12 structure. Direct cobalt intake is rarely needed and is mainly considered when B12 status is addressed.
Benefits are primarily achieved by correcting vitamin B12 deficiency, improving anemia and neurologic function. Direct cobalt salts can stimulate erythropoiesis pathways, but this is not an appropriate nutritional strategy. Minority claims of energy enhancement lack reliable evidence. Excess cobalt can be toxic, affecting cardiac, thyroid, and neurologic function.
Cobalt functions in humans exclusively as the central ion in cobalamin (vitamin B12), enabling methyl-transfer and isomerization reactions for DNA synthesis, erythropoiesis, and myelin maintenance. Inorganic cobalt salts are toxic, causing cardiomyopathy, thyroid suppression, and polycythemia via HIF-1α stabilization.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Essential only as part of vitamin B12 for DNA synthesis and red blood cell formation
- No independent supplementation benefit. Isolated cobalt is exclusively a toxicology concern
Secondary Outcomes
- Inorganic cobalt stimulates EPO via HIF-1α (prohibited doping mechanism)
- Historical anemia treatment abandoned due to cardiomyopathy deaths
Safety
Contraindications and Interactions
Contraindications
- All individuals (inorganic cobalt)
- Pre-existing cardiac disease
- Thyroid disorders
- Renal impairment
Side effects
- Cardiomyopathy
- Thyroid dysfunction and goiter
- Polycythemia
- Nephrotoxicity
- Peripheral neuropathy
- GI irritation
Interactions
- EPO and erythropoiesis-stimulating agents (additive polycythemia)
- Thyroid medications (iodine competition)
- Iron metabolism interference
Avoid if
- Everyone. No population should supplement inorganic cobalt
- Metal-on-metal implant patients (already elevated cobalt)
Evidence
Study-level References
cobalt-SRC-001Review
Sourceopen_in_newPaustenbach DJ, Tvermoes BE, Unice KM, et al. A review of the health hazards posed by cobalt. Crit Rev Toxicol. 2013;43(4):316-362. doi:10.3109/10408444.2013.779633. PMID:23656559.
Population: Humans exposed to cobalt through diet, supplements, occupation, and medical devices
Dose protocol: Synthesis of toxicological evidence across dietary, occupational, and medical device exposure routes. Adverse cardiomyopathy and sensory impairment reported at blood cobalt above 700 ug/L, with hypothyroidism and polycythemia at approximately 300 ug/L.
Key findings: Inorganic cobalt ions are linked to serious dose-dependent toxicity: dilated cardiomyopathy (beer drinker's cardiomyopathy from cobalt-contaminated beer in the 1960s), thyroid dysfunction (goiter via iodine uptake inhibition), polycythemia (HIF-1alpha/EPO pathway activation), nephrotoxicity, and neurological damage. Humans cannot convert inorganic cobalt to vitamin B12. Risk monitoring is recommended starting at serum cobalt of 100 ug/L.
Notes: Definitive modern review supporting the classification of isolated cobalt as a toxicological hazard rather than a supplement candidate. Supports WADA prohibition of CoCl₂.
Paper content
This comprehensive review examines the health hazards of cobalt, an essential element with ubiquitous dietary exposure and possible additional exposure from dietary supplements, occupational settings, and medical devices. Adverse health effects including cardiomyopathy and sensory impairment were associated with elevated blood cobalt concentrations. The review evaluates dose-response relationships and identifies uncertainty in current risk assessments.
cobalt-SRC-002Review
Sourceopen_in_newSimonsen LO, Harbak H, Bennekou P. Cobalt metabolism and toxicology--a brief update. Sci Total Environ. 2012;432:210-215. doi:10.1016/j.scitotenv.2012.06.009. PMID:22732165.
Population: Humans and animals exposed to cobalt through environmental or occupational sources
Dose protocol: Review of cobalt metabolism and toxicology covering Co2+ stabilization of HIF and stimulation of erythropoietin production.
Key findings: Co2+ stabilizes HIF-1alpha, mimicking hypoxia and stimulating endogenous EPO production. Cobalt salts may be misused by athletes as an alternative to EPO doping for enhancing aerobic performance. The review documents genotoxic potential, tissue distribution, and modern exposure risks from orthopedic implants alongside the cardiovascular and thyroid toxicity profile.
Notes: Establishes the anti-doping context for cobalt prohibition and documents the mechanism of its misuse.
Paper content
This review summarizes cobalt metabolism and toxicology with a focus on recent understanding of cobalt interference with cellular oxygen sensing. Cobalt (Co2+) stabilizes the hypoxia-inducible factor (HIF), which has implications for erythropoiesis and other physiological processes. The review covers cobalt pharmacokinetics, environmental exposure, and toxicity in human and animal models.
cobalt-SRC-003Cohort study
Sourceopen_in_newHe C, Gao M, He T, Xing F. Association of cobalt exposure with all-cause and cardiovascular mortality in U.S. adults. BMC Public Health. 2025;25(1). doi:10.1186/s12889-025-22753-w. PMID:40361032.
Population: U.S. adults from NHANES 1999-2018 with urinary cobalt data (n=15,873) and 2015-2018 with blood cobalt data (n=6,692)
Dose protocol: Prospective cohort analysis of NHANES 1999-2018 data (n = 15,873 for urinary cobalt, n = 6,692 for blood cobalt) with mortality follow-up through December 2019 (median 130 months).
Key findings: Higher cobalt exposure was significantly associated with increased all-cause and cardiovascular mortality in U.S. adults. Blood cobalt showed adjusted hazard ratios of 1.57 for all-cause mortality and 2.02 for cardiovascular mortality. The population attributable fraction for participants with urinary cobalt above the 80th percentile was 5.5% for all-cause mortality and 9.5% for CVD mortality.
Notes: Large-scale epidemiological evidence linking environmental and dietary cobalt exposure to mortality outcomes in the general population, reinforcing the toxicological concern beyond implant and occupational settings.
Paper content
This NHANES cohort study found that environmental cobalt exposure, measured via urinary and blood cobalt levels, was significantly associated with increased all-cause and cardiovascular disease mortality in U.S. adults over a median follow-up of 130 months.