Can iron supplements affect taste?

Can Iron Supplements Affect Taste?

Iron deficiency itself causes taste disturbances, but iron supplements do not typically cause taste alterations as a side effect of the medication—rather, they correct taste abnormalities caused by the underlying iron deficiency. 1, 2

Iron Deficiency as a Cause of Taste Disturbances

• Iron deficiency is a recognized cause of hypogeusia (decreased taste sensation), with clinical studies demonstrating that approximately 28% of patients with taste abnormalities have underlying iron deficiency 2
• Patients with iron deficiency-related taste disturbances typically experience elevated taste thresholds, particularly for sour tastes, which normalize with iron supplementation 1
• Treatment with iron supplements successfully corrects taste disturbances caused by serum iron deficiency in the majority of patients, with taste thresholds decreasing as the taste sensation improves 1, 2

Iron Supplements and Taste Side Effects

• Iron supplements themselves do not cause taste alterations as a direct pharmacologic side effect 3, 4
• The common side effects of oral iron supplementation are gastrointestinal in nature, including nausea (29-63%), constipation (4-29%), diarrhea (8%), and flatulence, but taste changes are not among the documented adverse effects 5, 4
• One exception is trientine (a copper chelator used in Wilson's disease), which can cause loss of taste as a side effect, but this is not relevant to standard iron supplementation 5

Clinical Implications

• If a patient develops taste disturbances while taking iron supplements, investigate alternative causes rather than attributing it to the iron medication itself 1, 2
• Other common causes of taste disturbances include oral candidiasis, xerostomia (dry mouth), psychiatric distress, and certain medications—all of which should be evaluated 2
• Zinc deficiency is also a well-known cause of taste disturbances and may coexist with iron deficiency, though serum zinc levels are often normal in patients with iron deficiency-related taste changes 1, 2

Important Caveats

• The unpleasant metallic taste some patients report with liquid iron preparations is related to the formulation stability and direct contact with taste receptors, not a systemic side effect 6
• This can be minimized by using tablet formulations rather than liquid preparations, or by taking the supplement with food (though this reduces absorption) 3, 6
• Nutritional supplements in general can cause off-taste or aftertaste due to the presence of active compounds, but this is a local sensory phenomenon rather than a systemic effect on taste perception 7