Experts say data doesn't support call to make high dose Vitamin B6 a drug

08-Oct-2021 - Last updated on 08-Oct-2021 at 16:42 GMT

Should high dose Vitamin B6 supplements be available only by prescription? A recent citizen petition says yes. ©Getty Images - Tom Werner

Related tags Vitamin b6 overdose regulations

Vitamin B6 supplement dosages should be restricted to 10 mg/day or less, with higher dosages sold only as prescriptions, a citizen petition to FDA has requested. Industry stakeholders say the action is unwarranted and ignores already established safe upper limits.

The petition, filed in late September by a analytical laboratory firm, claims that Vitamin B6 overdose is not only possible, but has occurred on a number of occasions. The firm, Emery Pharma, is owned by Ramin Najafi, PhD, who holds a chemistry doctorate from the University of California Davis.

The petition maintains that, “It is well established that when taken in excess, Vitamin B6 can cause symptoms of peripheral neuropathy and neurotoxicity.” The petition characterizes doses of 50 mg and more as ‘megadoses.’

Petition provides case study of problems from 100 mg dose

The petition includes a case study of a patient who reportedly had been taking 100 mg of Vitamin B6 per day. The patient, a 63-year-old man, experienced burning and tingling in the hands and feet which grew progressively worse. A test revealed the level of B6 in his system was about five times the median normal level. After ceasing B6 supplementation, his symptoms gradually subsided but did not disappear altogether.

The petition seeks two specific actions:

That FDA mandate a warning on the labels of vitamin B6 products that world read: “This medication may be dangerous when used in large amounts or for a long time. Stop taking this medication if you experience tingling, burning, or numbness and see your healthcare practitioner as soon as possible. “
That the Agency mandate that dosages of Vitamin B6 greater than 10 mg be sold by prescription only.

There are many Vitamin B6 supplements on the market in dosages ranging up to 100 mg/serving. All dietary supplement manufacturers are required by law to collect adverse event reports and to report serious events on to an FDA-maintained database. As these kinds of products have been on the market continuously since the adverse event reporting requirement became law in 1997, it stands to reason that there a comprehensive trove of data to mine on the subject of Vitamin B6 safety.

Expert: AER data does not support petition

Rick Kingston, PharmD, is one of the foremost experts on finding safety signals within such data. Kingston is a professor in the University of Minnesota School of Pharmacy as well as being the president of regulatory and scientific affairs at SafetyCall International, which helps dietary supplement firms and other companies manage adverse event reporting and recalls.

From Kingston’s point of view, that record doesn’t support Najafi’s petition. Kingston found only a handful of AERs relating to Vitamin B6 against a background of probably many hundreds of millions of doses of the vitamin in supplement form that have been consumed since 1997.

“In looking at the FDA CAERS data, there have been AERs reported in the last few years but only about 22 reports that I could find, without clear trends in adverse effects. It is also unknown how many of those cases involve acute vs. chronic administration and what the actual doses were as that information is not available from in the data download nor is any narrative regarding the incident. One thing that I did notice is that the vast majority of these AERs involve individuals over 60 years of age including 10 individual over 70 years of age,” Kingston said.

“As for whether or not Vitamin B6 should be relegated to prescription only, I don’t think the AER data by itself is compelling. And, as for the suggested changes in labeling, there should be more discussion and review of the safety data,” he added.

Kingston noted that AER data is often incomplete, and some of those events might be related to individuals who are particularly sensitive for one reason or another.

Daniel Fabricant, PhD, president and CEO of the Natural Products Association, echoed that caveat.

“You can you take too much of anything, including water,” Fabricant said. “Saying that the premise of this petition is false is being kind. It is not supported by any of the available data.”

CRN: Safety issue has already been put to rest

The Council for Responsible Nutrition provided a statement reiterating that the question of Vitamin B6 safety has been exhaustively considered already.

“The petitioner’s requests for FDA to require a warning statement on Vitamin B6 or B-complex product labeling and to limit products containing more than 10 mg of Vitamin B6 to be available by prescription only, are not supported by credible scientific evidence. In addition to lacking the scientific data that would be necessary for these policy changes, the requests would be harmful to consumers and deny them access to a range of beneficial products,” CRN said.

“The citizen petition largely ignores the safe level of 100 mg/day for Vitamin B6 intake set by US authorities and does not include adequate information to warrant a change in this level. CRN’s own safety review, last conducted in 2014, is consistent with government recommendations that Vitamin B6 is safe at levels up to 100 mg/day. The petitioner’s requested actions would unnecessarily raise alarm and restrict access to an essential nutrient that is safely consumed by millions of Americans every day,” the organization concluded.