What vitamins cause body odor and when should you be concerned?

January 14, 2026 •

4 min read

According to the Cleveland Clinic, body odor isn't caused by sweat itself, but by bacteria on the skin breaking down the sweat. While hygiene and diet are often the main factors, less common causes linked to specific nutrients or metabolism, such as certain vitamins and minerals, can also result in an unusual body odor.

Quick Summary

Certain vitamins, most notably high doses of choline found in some B-complex supplements, can influence body odor, especially in individuals with a genetic condition called trimethylaminuria. Other contributing factors include severe vitamin C or zinc deficiencies. The odor typically resolves by adjusting supplementation, modifying diet, or managing the underlying metabolic issue.

Key Points

High-Dose Choline: Taking excessive amounts of choline, often present in high-potency B-complex supplements, is a primary nutritional cause of fishy body odor.
Trimethylaminuria (TMAU): Individuals with this rare genetic disorder cannot properly metabolize the compound trimethylamine (TMA), leading to a persistent fishy smell.
Other B Vitamins: High doses of other B vitamins, particularly Thiamine (B1), can also cause a strong, unpleasant smell in urine.
Deficiency Can Cause Odor: A severe vitamin C deficiency can result in putrid-smelling sweat, while a zinc deficiency may affect hormone production and contribute to changes in body odor.
Check Your Supplements and Diet: Reducing the dosage of high-choline supplements or adjusting intake of choline-rich foods can often help resolve the issue.
Consult a Professional: If unusual body odor is persistent, it is important to consult a healthcare provider to rule out underlying medical conditions or TMAU.

The Link Between Nutrients and Body Odor

While body odor is a natural process influenced by factors like genetics, hormones, and bacteria, a less common but significant cause can be related to nutrient intake or underlying metabolic issues. Vitamins, particularly in supplement form, can alter the body's biochemistry in ways that produce noticeable scents. For most people, this is a result of taking high doses of a specific nutrient, but in rare cases, a vitamin deficiency or a genetic disorder can be the root cause.

Choline and the Fishy Connection

One of the most widely reported links between vitamins and body odor involves choline. This essential nutrient is part of some B-complex supplements and is vital for brain function and cell membranes. However, excessive intake can lead to a distinct and unpleasant fishy smell.

The Mechanism: Choline is metabolized by gut bacteria into a compound called trimethylamine (TMA). Normally, a liver enzyme called flavin-containing monooxygenase 3 (FMO3) breaks down TMA into an odorless compound. When choline intake is too high, this enzyme can be overwhelmed, leading to a buildup of TMA in the body.
Trimethylaminuria (TMAU): This process is amplified in individuals with trimethylaminuria, or “fish odor syndrome,” a rare genetic disorder where the FMO3 enzyme is deficient or dysfunctional. In these individuals, even normal dietary intake of choline can cause a persistent fishy odor, which is excreted through sweat, urine, and breath. The condition can cause significant social and psychological distress.

Other B Vitamins and Their Effects

Beyond choline, other B vitamins can also affect body odor, particularly in excess. Thiamine (Vitamin B1) is a sulfur-containing compound, and high supplemental doses are known to cause a strong odor in urine. A vitamin B-complex supplement that is old or improperly stored can also develop a strong, unpleasant smell due to oxidation.

Deficiency-Related Body Odor

While excess is a more common cause of vitamin-related odor, certain severe deficiencies can also have an impact.

Vitamin C Deficiency (Scurvy): In the rare case of severe vitamin C deficiency, or scurvy, a symptom can be putrid-smelling sweat. This is an indication of a serious health problem, as scurvy also involves fatigue, gum disease, and slow wound healing.
Zinc Deficiency: Zinc is a mineral, but its connection to body odor is worth noting. It plays a role in hormone production and immune function. A deficiency can cause hormonal imbalances and inflammation, which may lead to changes in body odor. Zinc is also used topically in deodorants for its antibacterial properties, further highlighting its role in odor management.

Management and When to See a Doctor

If you suspect that vitamins are affecting your body odor, consider the following steps:

Review your supplements: Check the dosage and ingredients of any multivitamins or B-complex formulas you take. If they contain high amounts of choline, consider reducing the dosage or switching to a product without it.
Modify your diet: Since the body converts dietary choline into TMA, a healthcare professional may suggest reducing intake of choline-rich foods like eggs, organ meats, and certain cruciferous vegetables for individuals with TMAU. Conversely, increasing intake of vitamins like riboflavin (B2) may help those with TMAU, as it can assist the enzyme responsible for breaking down TMA.
Consult a doctor: If the odor is persistent, unusual, or accompanied by other symptoms, it's crucial to seek professional medical advice. A doctor can perform a physical exam and lab tests to rule out or diagnose underlying conditions like TMAU, liver disease, or kidney problems.

Comparing Vitamins and Their Impact on Body Odor


Nutrient/Compound	Condition	Type of Odor	Mechanism
Choline (high dose)	High intake, TMAU	Fishy	Converted by gut bacteria to TMA, which is released in sweat and breath.
Thiamine (B1)	High supplemental dose	Pungent/Urine-like	High levels can cause strong odor in urine.
Vitamin C	Severe deficiency (Scurvy)	Putrid sweat	Metabolic changes due to severe deficiency.
Zinc	Deficiency	Unspecified change	Affects hormonal balance and immune function.
Trimethylamine (TMA)	TMAU (genetic disorder)	Fishy/Rotting fish	Liver enzyme (FMO3) is deficient, causing TMA buildup.
B-complex (stored poorly)	Oxidation over time	Stale/Unpleasant	Oxidation of reactive compounds over time.

Conclusion

While a change in body odor can be unsettling, it is rarely a result of moderate vitamin intake. The most common vitamin-related causes are excessive doses of choline, often found in high-potency B-complex supplements, or a rare genetic disorder like trimethylaminuria. Severe deficiencies, such as scurvy, are also a possibility but are uncommon. The most important step is to assess your supplement use and consult a healthcare professional, especially if the odor is persistent or unexplained. They can help you identify the root cause and find the right solution for you, which may involve simple dietary changes, supplement adjustments, or treatment for an underlying condition. A healthy body should not smell bad because of its vitamins, but it is important to know when an issue might be signaling a deeper concern. For more detailed information on trimethylaminuria, consult a reliable resource such as the National Organization for Rare Disorders (NORD), which provides extensive information on the condition.

Frequently Asked Questions

Yes, taking high-dose B-complex supplements can cause an odor, particularly if the supplement contains high levels of choline. For those with a rare genetic condition called trimethylaminuria (TMAU), this can lead to a persistent fishy body odor.

High doses of choline can cause a fishy body odor because it is metabolized by gut bacteria into trimethylamine (TMA). In most people, a liver enzyme breaks TMA down, but excessive intake can overwhelm this process. This effect is especially pronounced in those with trimethylaminuria.

Trimethylaminuria is a rare genetic disorder where the body cannot properly metabolize trimethylamine (TMA), a compound with a pungent, fishy odor. The buildup of TMA is then released through sweat, urine, and breath. It is linked to the FMO3 liver enzyme.

Yes, although it is less common. A severe deficiency in vitamin C (scurvy) can lead to putrid-smelling sweat. A zinc deficiency may also cause body odor changes due to its impact on hormonal balance and inflammation.

If you suspect a supplement is causing odor, consider reducing your dosage or consulting a healthcare provider about switching to a different product. For those with TMAU, restricting choline-rich foods and supplementing with riboflavin (B2) may also help.

Yes, some vitamins can cause a strong odor in urine. High intake of B vitamins, especially Thiamine (B1), is often the cause. This is generally harmless and occurs as the body excretes excess nutrients.

Some supplements, like zinc and magnesium, have been anecdotally associated with improved body odor by supporting detoxification and hormonal balance. For individuals with TMAU, riboflavin (B2) may be beneficial. Always consult a doctor before starting a new supplement regimen.