Excess Vitamin Caused Neuropathy

Most people who take supplements expect that their health will improve as a result. However, we have heard from numerous people who have found, to their chagrin, that the supplement they take has actually led to problems. Scientific studies have shown that excessive vitamin B6 taken over a lengthy period of time can damage the nerves (Advances in Nutrition, Oct. 1, 2021). Sometimes lower levels of the vitamin are responsible. One reader discovered that a multivitamin caused neuropathy, while another traced the problem to brewer’s yeast.

Perhaps Multivitamins Caused Neuropathy:

Q. I have been trying to take good care of my health. I exercise, eat well and was taking a multivitamin for 50+ women.

Last winter I noticed that my toes were becoming tingly, especially when I was in bed. At times my toes ached when I was walking. Then I read a comment in one of your columns about vitamins where a woman mentioned tingling toes and that her doctor told her to quit taking her multivitamin because it contained a high dose of vitamin B6, much more than the DV.

My multi had 1,000 percent of DV for vitamin B6, so I quit taking them. After two weeks all the tingling stopped and has not happened again.

I have checked labels of multi-vitamins and notice that many have high percentages of DV. Why?

On the Mayo Clinic website, I read that high amounts of vitamin B6 are toxic, and it can take a long time for toe tingling to stop if that’s the cause. Consequently, I no longer take a multivitamin. I certainly do not want to create problems by taking one!

Do Multivitamins Contain Excess Vitamin B6?

A. Doctors have a name for the sensation of tingling or pain in the toes: peripheral neuropathy. Some people report feeling as if they had cotton stuffed under their toes.

We suspect that multivitamins do not often cause neuropathy. However, it certainly makes sense to check the label and avoid those that exceed the Daily Value (DV). By the way, the DV for vitamin B6 is 1.7 mg.

In a published case report, the 73-year-old patient had been taking his multivitamin for more than ten years (Cureus, Nov. 14, 2023). His peripheral neuropathy symptoms troubled him for three years before the doctors pinpointed vitamin B6 as the cause. His blood level was elevated. About a month after stopping his daily vitamin, his tingling and numbness had begun to improve.

Did Anti-Acne Supplements Result in Neuropathy?

Q. When I was a teenager I had a brief bout with acne. A friend of my mother said I should take baker’s yeast. I took it for two weeks and it cleared up my skin. Because I hated the taste, I switched to brewer’s yeast tablets. Over the past 40 years, I have been conscientiously taking five a day.

Over the last few years I have had trouble with numbness in my feet. It’s a weird sensation, as though there were plastic wrap around them. A neurologist sent me for a battery of blood tests to rule out a vitamin B6 deficiency. He said it could cause peripheral neuropathy like mine.

My test results came back sky high. My B6 levels were seven times normal. Brewer’s yeast is high in vitamin B6. It turns out that either too little or too much of this vitamin can cause peripheral neuropathy.

A. Neurologists consider the nerve damage that occurs from vitamin B6 (pyridoxine) toxicity as a stocking-glove phenomenon. The numb sensation you described was a red flag. People are usually advised to keep their vitamin B6 intake under 100 mg daily.