There is an increasing recognition of the rare yet potentially severe side effects associated with high doses of vitamin B6. This nutrient has gained significant popularity and is now commonly found in various dietary supplements, electrolyte drinks, and fortified foods.
Vitamin B6, also known as pyridoxine, plays a critical role in many bodily functions, including nerve health, protein metabolism, and blood sugar control. As it is essential for brain development, its intake is especially important during pregnancy and infancy. Many promote this vitamin to enhance energy levels and alleviate stress.
This nutrient naturally exists in several foods and is often added to ready-to-eat products, particularly cereals. Most multivitamins contain B6, according to the National Institutes of Health’s Office of Dietary Supplements.
According to Jamie Alan, an associate professor of pharmacology and toxicology at Michigan State University, vitamin B6 is also included in some energy drinks as an alternative to caffeine. She stated, “People might be surprised at the numerous sources of B vitamins.”
This widespread presence could be contributing to the issue.
When taken in high doses, vitamin B6 can accumulate in the body and lead to nerve damage, cautioned Dr. Norman Latov, director of the Peripheral Neuropathy Clinical and Research Center at Weill Cornell Medicine in New York.
In November, cases of presumed vitamin B6 poisoning prompted the Australian government to impose stricter regulations on supplements containing elevated amounts of this nutrient. Starting in mid-2027, products with over 50 milligrams per daily dose will be sold behind pharmacy counters; those with over 200 mg already require a prescription.
Nonetheless, interest in vitamin B6 products continues to rise, with predictions indicating a global market exceeding $712 million by 2030 and a 5.8% compound annual growth rate between 2024 and 2030, according to data from research analytics firm IndustryArc.
While poisoning is rare, incidents are increasing. In 2024, there were 439 reported cases of vitamin B6 exposure across the nation—none of which were fatal—up from 369 in 2019 and 311 in 2014, according to National Poison Data System records.
Joanne Slavin, a registered dietitian and professor of food science and nutrition at the University of Minnesota, noted that many individuals assume water-soluble vitamins, such as B6, are harmless. Unlike fat-soluble vitamins, which the body can store, water-soluble vitamins are expelled in urine and must be consumed regularly.
“People need to understand that vitamins are not inert—they’re chemicals,” Slavin emphasized. “You don’t need to overconsume them.”
B6 toxicity may be frequently underreported since symptoms progress slowly, and individuals might not realize they are consuming excessive amounts. Dr. Latov remarked, “It sneaks up on you,” estimating that 5% to 10% of patients with neuropathy at his center exhibit high B6 levels.
Initial symptoms can be mild, such as occasional numbness in the toes, which might be disregarded. This can escalate to sensations of heat, cold, stinging, or tingling that starts in the feet and can ascend through the legs.
Other signs may encompass nerve pain, numbness, imbalance, muscle weakness, changes in blood pressure, in addition to fatigue, heartburn, and nausea.
A blood test can help identify if vitamin B6 levels are excessively high.
“There’s a substantial margin of safety for B6, meaning that you can exceed the recommended dose and still be fine,” Alan explained. “However, anything taken in high enough doses can have adverse effects—even water.”
A Colorado woman’s experience with vitamin B6 poisoning
When Blair Huddy relocated from California to Colorado in 2024, she was advised by many to stay well-hydrated, as dehydration can intensify altitude sickness.
Consequently, Huddy, now 36, began using an electrolyte drink mix in December of that year. She reported consuming one packet daily, mixing it with 16 ounces of water. The packet indicated it contained 1.93 mg, or 110% of the recommended daily intake, of vitamin B6.
Almost immediately, Huddy experienced unexplained symptoms such as vertigo, heart palpitations, and adrenaline surges. Unaware of a possible connection, she continued to use the drink mix. By January 2025, she began experiencing allergy-like symptoms, followed by sleep disturbances. In March, after trying chicken liver for the first time—a food rich in vitamin B6—she was hospitalized for suspected anaphylaxis and heart complications, despite having never had a food allergy before.
“It was terrifying. I had no idea what was happening to me,” Huddy recounted. “I was consuming one [drink mix packet] daily, thinking I was simply hydrating.”
After her hospital stay, Huddy developed peripheral neuropathy, which affects the nervous system outside the brain and spinal cord, as well as tinnitus.
“I kept going back to the doctor, insisting that something was genuinely wrong,” Huddy said, explaining that her symptoms were dismissed as manifestations of her generalized anxiety disorder. “I was repeatedly sent home without answers.”
In May, Huddy urged a doctor to perform blood tests.
“A nurse called to inform me that my vitamin B6 levels were over twice the upper limit,” Huddy said. “‘You need to stop taking whatever it is that has B6 in it.’”
How much vitamin B6 is safe?
The recommended daily allowance for B6 varies from 1.3 mg for younger adults to 1.5 mg for women over 50 and 1.7 mg for older men.
Foods rich in vitamin B6 include poultry, fish, beef liver and other organ meats, potatoes and starchy vegetables, as well as non-citrus fruits. Experts suggest that most individuals receive sufficient B6 from their diets.
In the United States, the upper limit for B6 intake for adults is set at 100 mg. In contrast, the European Food Safety Authority has established a maximum of 12 mg per day, while Australia’s limit is 50 mg.
The Council for Responsible Nutrition, representing supplement manufacturers, has also set its own upper limit of 100 mg per day for supplemental B6. This amount is deemed safe for the generally healthy population, noted Andrea Wong, the group’s senior vice president and chief science officer. However, those with specific health issues may require more or less.
“It will depend on the individual and their body’s metabolism and ability to process the vitamin,” Wong added. “Various factors may influence any potential effects you experience.”
A small 2020 study published in the journal PharmaNutrition identified that diet, genetics, and medication use might contribute to vitamin B6 toxicity—potentially even at recommended levels.
Vitamin B6 can appear on nutrition labels as pyridoxine, pyridoxal, or pyridoxamine, denoting its various chemical forms.
“Ensure you review all your sources and total the intake to ensure it aligns with your needs,” Wong advised.
B6 can remain in the body for 30 to 40 days. If supplementation is halted, symptoms should improve, noted Latov, although “depending on the extent of the damage, nerve regeneration may not be complete.”
Huddy attributes her poisoning to the electrolyte drink mix she consumed daily for six months. She doubts her diet contributed and stated she didn’t take additional supplements.
While she continues to recover, she experiences lingering tinnitus and is undergoing physical therapy for nerve complications. She has returned to work and is also informally supporting others who face vitamin B6 toxicity.
“I wish I had someone to guide me through it the way I can now help others,” Huddy reflected.
