Is there an association between iron deficiency and dysgeusia?

Iron Deficiency and Dysgeusia: The Established Connection

Yes, there is a clear association between iron deficiency and dysgeusia (abnormal taste sensation). Clinical evidence demonstrates that iron deficiency can directly cause taste abnormalities, which may improve with iron supplementation.

Evidence for the Association

• A clinical investigation specifically examining taste abnormalities found that iron deficiency was identified as the cause of hypogeusia (decreased taste sensation) in 7 out of 25 patients studied 1
• This research demonstrated that decreased serum iron levels were observed in these patients, while zinc and copper levels remained normal 1
• Importantly, the study showed that hypogeusia induced by iron deficiency was accompanied by elevation of taste thresholds, confirming the physiological impact 1

Mechanism and Presentation

• Iron deficiency can affect taste perception through multiple mechanisms:

  • Reduced activity of iron-dependent enzymes needed for proper taste bud function 1
  • Heme (an iron-containing compound) may function as a taste molecule itself, with research suggesting it plays a primary role in metallic taste perception 2
  • Iron deficiency can cause general symptoms like fatigue and difficulty concentrating, which may indirectly affect taste perception 3

• The taste abnormalities typically present as:

  • Decreased taste sensation (hypogeusia) with elevated taste thresholds 1
  • Metallic taste sensation, which may be related to altered heme perception 2

Clinical Implications

• When evaluating patients with dysgeusia, iron deficiency should be considered as a potential cause 1

• Testing for iron deficiency is indicated for patients with taste abnormalities and can be diagnosed by:

  • Low serum ferritin (typically <30 ng/mL) in individuals without inflammatory conditions 3
  • Transferrin saturation less than 20% 3

• Supplementing zinc and vitamin A may also help improve dysgeusia in certain conditions, though the evidence specifically for iron deficiency-related dysgeusia is stronger 4

Treatment Approach

• Oral iron supplementation (ferrous sulfate 325 mg/day or on alternate days) is typically the first-line therapy for iron deficiency 3
• Intravenous iron may be necessary for patients with oral iron intolerance, poor absorption, chronic inflammatory conditions, or ongoing blood loss 3
• Clinical evidence suggests that taste abnormalities improve when iron deficiency is corrected 1

Important Considerations

• While iron deficiency is a documented cause of dysgeusia, other common causes should also be considered in differential diagnosis, including:

  • Oral candidiasis 1
  • Hyposalivation/xerostomia 1
  • Psychiatric distress 1
  • Medication side effects 1

• Unlike zinc deficiency, which has shown inconsistent associations with taste disorders, iron deficiency has demonstrated a more reliable connection to dysgeusia 1, 5