Can too much vitamin E cause diarrhea? Understanding the Risks of High-Dose Supplements

November 30, 2025 •

3 min read

While vitamin E is a necessary nutrient, taking very high doses in supplement form can occasionally cause muscle weakness, fatigue, nausea, and, importantly, can too much vitamin E cause diarrhea. These gastrointestinal side effects are often among the first signs that you are exceeding a safe intake level and may need to adjust your supplementation. Understanding the distinction between dietary and supplemental intake is crucial for avoiding these unwanted health effects and preventing more serious complications.

Quick Summary

Taking excessive doses of vitamin E supplements can cause gastrointestinal side effects, including diarrhea. The tolerable upper intake level for adults is 1,000 mg daily, and exceeding this significantly increases toxicity risk, with symptoms like nausea and fatigue accompanying digestive upset. Food sources of vitamin E are not linked to this risk. Discontinuing high-dose supplements typically resolves the issue.

Key Points

Diarrhea is a Symptom: High doses of vitamin E supplements can cause diarrhea, along with other gastrointestinal issues like nausea and cramping.
Supplements are the Source: Vitamin E toxicity and associated side effects are almost exclusively caused by high-dose supplements, not from consuming vitamin-rich foods.
Recognize the UL: For adults, the Tolerable Upper Intake Level (UL) for supplemental vitamin E is 1,000 mg (or 1,500 IU natural / 1,100 IU synthetic), and symptoms occur when intake exceeds this.
Monitor for Other Symptoms: In addition to digestive issues, high intake can lead to fatigue, muscle weakness, and, most seriously, an increased risk of bleeding.
Stop and Consult: If you experience side effects, stop taking the supplement and talk to a healthcare provider, especially if you are on blood-thinning medication.
Food is Safest: Rely on natural food sources for your vitamin E needs, as they provide safe and balanced levels of the nutrient without the risk of toxicity.

Can Too Much Vitamin E Cause Diarrhea?

Yes, excessive intake of vitamin E, particularly from supplements, can lead to diarrhea. Diarrhea, along with other gastrointestinal issues like nausea and abdominal cramps, is a known side effect of vitamin E toxicity. Unlike water-soluble vitamins, which the body can easily excrete, vitamin E is fat-soluble and stored in the body, potentially accumulating to toxic levels with consistently high intake.

The Tolerable Upper Intake Level (UL) for supplemental vitamin E in adults is 1,000 mg daily (equivalent to 1,100 IU for synthetic and 1,500 IU for natural vitamin E). Exceeding this limit significantly increases the risk of gastrointestinal distress. It's crucial to understand that consuming vitamin E from food sources does not pose this risk.

Understanding the Difference: Dietary vs. Supplemental Vitamin E

The risk of vitamin E toxicity, including diarrhea, is primarily linked to supplement use rather than dietary intake. Food sources contain lower, more manageable concentrations of vitamin E.

Vitamin E from Food Sources

Sources: Rich foods include vegetable oils like wheat germ, sunflower, and safflower oils, as well as nuts and seeds.
Safety: It is highly improbable to reach toxic vitamin E levels through diet alone due to lower concentrations and the body's natural regulation.

Vitamin E from Supplements

Concentration: Supplements often provide doses far exceeding the Recommended Dietary Allowance (RDA) of 15 mg for adults.
Risk: High-dose supplements can easily lead to exceeding the UL, causing side effects like diarrhea and, more importantly, an increased risk of bleeding.

Other Symptoms of Vitamin E Toxicity

Diarrhea is one indicator of excessive vitamin E. Other potential symptoms of high intake include:

Increased Bleeding Risk: This is a serious concern with high doses, as vitamin E can hinder blood clotting. This risk is particularly high for individuals on blood thinners and can potentially cause hemorrhagic stroke.
Nausea and Abdominal Cramps: These digestive symptoms often accompany diarrhea when vitamin E intake is too high.
Fatigue and Muscle Weakness: High levels may also cause tiredness and affect muscle function.
Headaches and Blurred Vision: These can also be signs of chronic, high-dose supplementation.

A Comparison of Safe vs. Excessive Vitamin E Intake


Aspect	Safe Intake (from Food)	Excessive Intake (from Supplements)
Source	Balanced diet rich in vegetable oils, nuts, and leafy greens.	High-dose capsules or tablets, often 400 IU or higher.
Dosage	At or below the RDA (15 mg for adults).	Significantly above the UL of 1,000 mg (1,500 IU natural / 1,100 IU synthetic).
Risk of Diarrhea	Extremely low to nonexistent.	Occasional side effect, especially with doses far exceeding the UL.
Bleeding Risk	Not a concern.	Significant risk, especially for those on blood thinners.
Severity	High intake is well-tolerated.	Can cause mild GI upset to life-threatening hemorrhagic stroke.
Action Required	Continue normal, healthy eating habits.	Discontinue supplements immediately and consult a healthcare provider.

What to Do If You Suspect Too Much Vitamin E

If you experience diarrhea or other symptoms while taking vitamin E supplements, stop taking them immediately. Mild gastrointestinal issues may resolve on their own after stopping supplementation. It is advisable to consult a healthcare professional to review your supplement use and ensure your intake is safe.

For individuals taking anticoagulant or antiplatelet medications, seeking medical advice is essential due to the increased bleeding risk. Your doctor can evaluate your situation and recommend the best course of action. Digestive issues can serve as an early warning sign of excessive intake.

The Bottom Line: Can Too Much Vitamin E Cause Diarrhea?

Yes, excessive vitamin E from supplements can cause adverse effects, including diarrhea. While less severe than the bleeding risks associated with very high doses, diarrhea indicates that your intake is too high. Prioritizing vitamin E from food sources is the safest approach. If supplementation is needed, do so under the guidance of a healthcare professional and adhere to recommended dosages, never exceeding the UL without medical supervision. For further information, the NIH Office of Dietary Supplements is a valuable resource.

Frequently Asked Questions

For adults, the Tolerable Upper Intake Level (UL) is 1,000 mg (1,500 IU natural / 1,100 IU synthetic) of supplemental vitamin E per day. Consistently exceeding this level increases the risk of side effects, including diarrhea and bleeding problems.

No, it is highly unlikely to experience diarrhea or other toxicity symptoms from vitamin E obtained solely through your diet. The concentration of the vitamin in foods is not high enough to cause an overdose.

Other symptoms of vitamin E excess include nausea, headaches, fatigue, muscle weakness, and, in severe cases, an increased risk of bleeding.

The first step is to immediately stop taking the vitamin E supplement. For mild cases, the symptoms will typically subside on their own. However, it is recommended to speak with a healthcare professional to review your supplement use.

Yes, especially due to the increased risk of bleeding. This is particularly dangerous for individuals taking blood-thinning medications and can potentially lead to life-threatening hemorrhagic stroke.

For most healthy individuals, vitamin E supplements are not necessary, as enough of the vitamin can be obtained from a balanced diet. Unless a deficiency is identified by a healthcare provider, supplementation with high doses is generally not recommended.

The exact mechanism isn't fully understood, but it's likely related to gastrointestinal irritation and the body's struggle to process and absorb the excessively high amount of the fat-soluble vitamin. It can disrupt normal digestive function, leading to loose stools.