Can You Take Too Much Choline? Understanding the Upper Limit and Side Effects

December 13, 2025 •

4 min read

While choline is a vital nutrient for brain function, cell membrane formation, and fat metabolism, the body can indeed have too much. For healthy adults, the Tolerable Upper Intake Level (UL) is set at 3,500 mg per day to prevent adverse effects.

Quick Summary

Taking excessive amounts of choline, most often through high-dose supplements, can cause unpleasant side effects such as digestive upset, low blood pressure, excessive sweating, and a fishy body odor. It is highly unlikely to exceed the safe upper limit from food sources alone, and risks are primarily associated with high-dose supplementation.

Key Points

Tolerable Upper Limit (UL) exists: For healthy adults, the maximum safe daily intake of choline is 3,500 mg, with lower limits for younger age groups.
Toxicity is supplement-driven: It is extremely unlikely to consume a toxic amount of choline from food sources alone; overdose risk is linked to high-dose supplements.
Key side effects: Symptoms of excessive choline intake include a fishy body odor, gastrointestinal issues like diarrhea and nausea, low blood pressure, and increased sweating.
Some are more sensitive: People with pre-existing conditions like kidney or liver disease or the rare genetic disorder trimethylaminuria may be more susceptible to adverse effects.
Food is the safest source: A balanced diet rich in eggs, meat, fish, and certain vegetables provides sufficient choline without posing a risk of toxicity.
Prioritize diet first: It is recommended to meet choline needs through a varied diet rather than resorting to high-dose supplements, which carry greater risk.

What is the Tolerable Upper Intake Level for Choline?

The Tolerable Upper Intake Level (UL) is the maximum daily intake that is unlikely to cause adverse health effects in healthy individuals. For choline, the UL varies by age group, as established by health authorities. For most healthy adults (19 years and older), the UL is 3,500 mg per day. The UL for adolescents (14–18 years) is 3,000 mg, while for children aged 9–13, it is 2,000 mg. These limits are based on preventing adverse effects such as low blood pressure and fishy body odor, and they apply to intake from both food and supplements. It's important to note that most people in the United States do not even meet the Adequate Intake (AI) for choline through diet alone, making toxicity from food consumption extremely rare.

Choline's Role: A Quick Overview

Choline is an essential nutrient, but unlike traditional vitamins, the body can produce small amounts in the liver, though not enough to meet daily needs entirely. It is a precursor to acetylcholine, a neurotransmitter critical for memory, mood, and muscle control. Choline is also vital for lipid transport and metabolism, cell membrane structure, and gene expression. This means adequate intake is crucial, but like any nutrient, balance is key.

Side Effects of Excessive Choline

When someone exceeds the Tolerable Upper Intake Level, they may experience several noticeable side effects. The most commonly reported issues relate to high doses from supplements, not from consuming choline-rich foods.

Common Adverse Effects:

Fishy body odor: This is a well-documented side effect caused by the body's breakdown of excess choline into trimethylamine (TMA). For some individuals, particularly those with a rare genetic disorder called trimethylaminuria, this effect is more pronounced.
Gastrointestinal distress: Nausea, vomiting, and diarrhea are frequent complaints associated with high-dose choline supplementation.
Low blood pressure (hypotension): Excessive choline can cause a drop in blood pressure, leading to symptoms like dizziness or lightheadedness.
Excessive sweating and salivation: These cholinergic effects are linked to the stimulation of nerve pathways and can be a sign of overconsumption.

Choline Intake: Food vs. Supplements

It is incredibly difficult to reach the UL for choline through diet alone, as natural food sources are not typically concentrated enough to cause toxicity. The risks are almost exclusively associated with high-dose supplements.

Choline in food vs. supplements


Feature	Food Sources of Choline	Choline Supplements
Source	Naturally occurring in foods like eggs, liver, fish, and cruciferous vegetables.	Synthetically produced as choline bitartrate, phosphatidylcholine, or lecithin.
Toxicity Risk	Extremely low risk of reaching UL. Eating a balanced diet poses no threat of overdose.	High risk if taking large, unregulated doses. Supplements make it easy to exceed the UL.
Typical Dose	Intake from a typical varied diet is usually well below the UL.	Doses can be very high, from 100 mg to several grams per capsule.
Nutrient Synergy	Choline is consumed alongside other vital nutrients, vitamins, and minerals.	Often provides isolated, high concentrations of choline, without other food-based cofactors.

What if you have a sensitive condition?

Some individuals may have an increased sensitivity to the adverse effects of choline. People with trimethylaminuria, liver disease, or kidney disease should be particularly cautious. Additionally, some studies have noted a link between very high choline intake and an increased risk of cardiovascular disease through the production of TMAO, although this area requires more research. Anyone with underlying health conditions should consult a healthcare provider before taking choline supplements.

Examples of high-choline foods

For those aiming for adequate intake without risk of overdose, focusing on a diet rich in these foods is the safest approach:

Eggs: One of the most concentrated sources, with one large egg providing around 147 mg.
Beef liver: A single 3-ounce serving of pan-fried beef liver contains 356 mg of choline.
Beef steak: A 3-ounce serving of beef top round can provide 117 mg.
Salmon: A great source of choline and omega-3 fatty acids.
Cruciferous vegetables: Brussels sprouts and broccoli contain moderate amounts.
Dairy products: Milk and yogurt contribute to overall choline intake.

Conclusion

Yes, it is possible to take too much choline, but toxicity is almost exclusively linked to high-dose supplementation and not to dietary intake from food. The Tolerable Upper Intake Level for adults is 3,500 mg per day, with doses above this threshold potentially causing side effects like a fishy body odor, digestive upset, and low blood pressure. The majority of the population does not meet the recommended daily intake, so concern over excess is usually unfounded for those relying on food alone. Individuals should prioritize a balanced diet for their choline needs and consult a healthcare professional before starting any high-dose supplement regimen. For more comprehensive information on choline, you can refer to the NIH Office of Dietary Supplements fact sheet.

Frequently Asked Questions

The Tolerable Upper Intake Level (UL) for healthy adults is 3,500 mg per day. This amount is based on preventing known adverse side effects like fishy body odor and low blood pressure.

Some of the first signs of excessive choline intake often include a fishy body odor, increased sweating, and digestive upset like nausea or diarrhea.

It is highly unlikely to get too much choline from food alone. The concentration of choline in foods is not typically high enough to cause toxicity, even with a diet rich in choline sources like eggs and liver.

Yes, high-dose choline supplements can cause problems. Since they provide concentrated amounts, it is much easier to exceed the Tolerable Upper Intake Level and experience side effects compared to getting choline from food.

When the body processes excess choline, it can be broken down into trimethylamine (TMA). TMA is responsible for the 'fishy' body odor associated with choline overdose.

Yes, high doses of choline can cause a drop in blood pressure, a condition known as hypotension. This can lead to symptoms such as dizziness or lightheadedness.

Individuals with certain medical conditions, such as liver disease, kidney disease, or trimethylaminuria, should be careful and consult a healthcare provider before taking choline supplements.