Nutrition Diet: What Vitamin Deters Midges? The Scientific Consensus

October 29, 2025 •

2 min read

Despite a folk remedy for preventing insect bites that has persisted since the 1940s, a comprehensive 2022 review of over 100 papers found that oral thiamine (vitamin B1) cannot repel arthropods in any dosage or route of administration. This widespread myth concerning what vitamin deters midges is scientifically unfounded.

Quick Summary

The myth that taking certain vitamins, particularly B1 (thiamine), can repel midges and other insects is contradicted by extensive scientific evidence. Relying on this unproven method can create a false sense of security, emphasizing the need for proven insect repellents and protective strategies.

Key Points

Thiamine is Ineffective: A 2022 systematic review of over 100 papers found that oral thiamine (vitamin B1) cannot repel midges or other arthropods at any dosage.
Midge Attractants are Unchanged: The bodily factors that truly attract midges, like carbon dioxide and heat, are not meaningfully altered by taking vitamins.
Rely on Proven Methods: Effective midge prevention relies on approved topical repellents containing DEET, picaridin, or Oil of Lemon Eucalyptus, along with physical barriers.
Avoid a False Sense of Security: Trusting an unproven dietary supplement for protection can leave you exposed and at risk, especially in areas with insect-borne diseases.
Environmental Management Helps: Simple measures like avoiding stagnant water and creating airflow with a fan can significantly reduce midge exposure.
Understand the Myth's Origin: The belief that Vitamin B1 repels insects stems from flawed, anecdotal reports from the 1940s, not controlled scientific studies.

The Origins of a Persistent Midge Myth

The idea that dietary supplements can prevent insect bites gained traction from a 1943 case report that was later deemed flawed. This report suggested consuming large doses of thiamine (vitamin B1) would create a scent repulsive to insects, a claim that was subsequently propagated through anecdotal evidence.

The Science Speaks: Controlled Studies Find No Repellent Effect

Rigorous scientific studies have consistently shown no evidence that vitamin B1 repels biting insects like midges. A 2005 study and a 2022 review both concluded that thiamine does not reduce mosquito or arthropod attraction. Reasons for anecdotal reports might include the placebo effect or changes in bite sensitivity over time.

What Really Attracts and Repels Midges

Midges are attracted to specific cues such as carbon dioxide, body heat, and individual body odor. A vitamin supplement does not interfere with these attractants.

Proven Strategies for Midge and Insect Protection

Effective midge deterrence relies on methods endorsed by health authorities, not unproven supplements.

Here are some of the most effective strategies:

Wear protective clothing: Covering skin with long sleeves and trousers is effective, especially during peak midge activity.
Use approved topical repellents: Apply repellents containing DEET, picaridin, or Oil of Lemon Eucalyptus as recommended by the CDC.
Create barriers: Use fine-mesh screens and fans, as midges are weak fliers.
Use citronella: Citronella products can provide localized repellent effects.
Avoid prime breeding grounds: Stay away from stagnant water and marshy areas.

Comparison of Midge Protection Methods


Protection Method	Description	Scientific Efficacy	Comments
Oral Vitamin B1 (Thiamine)	Ingesting large doses of thiamine supplements.	None	Relying on this can provide a false sense of security.
DEET-Based Repellents	Chemical topical application to skin and clothing.	High	A standard for insect repellency, recommended by health authorities.
Picaridin-Based Repellents	A synthetic compound applied topically.	High	Effective and often preferred for its lack of odor and non-greasy feel.
Oil of Lemon Eucalyptus (OLE)	Plant-based oil for topical use.	Moderate-High	A CDC-recommended natural alternative to chemical repellents.
Protective Clothing	Covering exposed skin with long-sleeved garments.	High	A physical barrier that directly prevents bites.
Essential Oils (Lavender, Peppermint)	Applying or diffusing essential oils.	Variable	Provides some effect, but generally less reliable and shorter-lasting than DEET or picaridin.

Conclusion: Prioritizing Proven Protection Over Dietary Myths

Scientific evidence confirms that no specific vitamin deters midges. Relying on unproven methods like vitamin B supplements is ineffective and can leave you vulnerable to bites and potential insect-borne diseases. The most effective protection involves using scientifically proven repellents, protective clothing, and environmental management. For safe midge prevention, trust established scientific recommendations.

For more information on effective insect repellents, refer to the CDC guidelines: https://www.cdc.gov/mosquitoes/mosquito-bites/prevent-mosquito-bites.html.

Frequently Asked Questions

No, like vitamin B supplements, claims that eating garlic or other foods will repel midges are anecdotal and lack scientific backing. Proven topical repellents are the most reliable method.

Positive anecdotal reports often result from a placebo effect, where a person’s belief in the treatment makes them perceive it as effective. Additionally, individuals’ sensitivity to bites can vary and decrease over time, which may be incorrectly attributed to the supplement.

For children, consult a healthcare provider for safe and appropriate repellent options, such as those with picaridin or Oil of Lemon Eucalyptus. Protective clothing is also a key strategy. The CDC provides specific guidelines for children.

No, controlled experiments on transdermal vitamin B patches and creams have also shown them to be ineffective at repelling insects. Rely on products with proven active ingredients.

Some essential oils, such as citronella, lemon eucalyptus, and peppermint oil, have repellent properties. However, their effectiveness can be less consistent and shorter-lived compared to CDC-approved chemical repellents.

Yes, it can be dangerous. In areas where insects carry diseases like malaria or Zika virus, relying on unproven remedies like dietary supplements can provide a false sense of security and leave you unprotected from serious illness.

Midges are most active during calm periods, especially around dawn and dusk. It is wise to take extra precautions during these times, such as wearing protective clothing or staying indoors if possible.