Can iron supplements cause teeth to turn yellow?

Iron Supplements and Teeth Discoloration

Yes, iron supplements can cause teeth to turn yellow or become stained. Research has demonstrated that different forms of iron supplements have staining potential on teeth, with some formulations causing more significant discoloration than others 1.

Evidence of Iron-Related Tooth Staining

• In vitro studies have confirmed that iron supplements can cause extrinsic staining on teeth, with the staining potential varying based on the specific iron formulation 1.
• A study specifically examining primary teeth found that iron syrups containing ferric oxide polymaltose (FOP) caused more significant staining than those containing ferrous fumarate (FF) after 72 hours of exposure 1.
• Interestingly, a combination of different forms of iron resulted in less intense staining than equivalent doses of a single form of iron 1.

Factors Affecting Iron-Related Tooth Staining

• Iron formulation: Different iron compounds have varying staining potential 1.
• Oral hygiene: A study of women with good oral hygiene found no detectable dental discoloration when taking ferrous fumarate tablets 2.
• Duration of exposure: Longer exposure to iron supplements increases staining potential 1.
• Concentration: Higher concentrations of iron may lead to more pronounced staining 3.

Mechanisms of Iron-Related Tooth Staining

Iron can cause extrinsic staining through:

• Direct contact between iron supplements and teeth
• Formation of ferric compounds on the tooth surface
• Possible interaction with lactoferrin (an iron-binding protein found in dairy products) 4

Prevention and Management of Iron-Related Tooth Staining

To minimize the risk of tooth staining while taking iron supplements:

1. Maintain excellent oral hygiene - Regular brushing and flossing can help prevent staining 2
2. Consider alternative iron formulations - Some formulations may cause less staining than others 1
3. Administration technique:
   • Take iron supplements with a straw to minimize contact with teeth
   • Rinse mouth thoroughly after taking liquid iron preparations
   • Consider taking tablets instead of liquid formulations when possible

Clinical Considerations

• The risk of tooth staining should be weighed against the benefits of treating iron deficiency anemia, which can significantly impact morbidity and mortality 5.
• For patients with severe iron deficiency who cannot tolerate oral iron or have malabsorption issues, intravenous iron formulations may be considered to avoid tooth staining 5.
• Regular dental cleanings may help remove extrinsic iron staining that does develop.

While tooth staining is a cosmetic concern, it's important to note that some research suggests iron may actually have cariostatic (cavity-preventing) effects 3, potentially offering a beneficial side effect alongside the aesthetic drawback of potential staining.