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High doses of vitamin B-6 can cause nerve damage and skin lesions, increase the risk of hip fracture, and have other adverse effects. If your multi contains 2,000% of the Daily Value (DV), which is 2 mg for adults, then your multi has 40 mg of B-6. [Note: In 2016, the FDA reduced the Daily Value for B-6 to 1.7 mg and 1.5 mg, respectively, for men and women age 51 and older, but this is not required to be reflected on all supplement labels until 2021.] While that amount alone does not exceed the Upper Tolerable Intake Limit for adults, it is important to consider the total daily amount you are getting from foods and other supplements, combined. Furthermore, there does not seem to be solid evidence to support getting such a large amount of B-6 if you are not deficient in it. The mega doses of vitamins found in some daily multis may be driven more by marketing considerations than science.

One clinical study found that 25 mg of B-6 taken daily as part of a B-complex vitamin was shown to increase the risk of heart attack, stroke and death in diabetes patients with advance kidney disease.

Other research has shown that high doses of vitamin B-6 might increase the risk or worsen progression of various types of cancer, including lung cancer, rectal cancer, and nasopharyngeal cancer.

Also, be aware that people taking certain medications may need to limit their intake of B-6 from supplements.

Get more information, including the Recommended Daily Allowances and Upper Limits for B-6 (by age and gender), potential side-effects and drug interactions, plus ConsumerLab's tests and comparisons of popular supplements, in the B Vitamin Supplements Review >>

You can check the recommended intakes of other vitamins and minerals here.

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March 25, 2021

Hello ,I just ordered the life extension mix tablet but i read it contain 105mg of b6!! Is this safe or should i avoid the product?
March 25, 2021

That is a high dose of B6 and exceeds the Tolerable Upper Limit for adults (100 mg). Generally, a dose this high is used if one is known to be deficient in B-6 and then stopped or switched to a lower dose or no supplementation when deficiency is corrected. Lower doses of B6 are difficult to find as single-ingredient supplements but can be obtained from a variety of B-complexes (see our Top Picks for B Vitamin Complexes

Susan 13888
April 2, 2017

Vitamin B-6 is a strong diuretic.

If you take B-6 in tablets or in foods within 6 hours of going to sleep, you may be getting up to urinate every few hours during the night. For some men, the problem isn't the prostate; but, this vitamin. Those energy drinks are over-loaded with B-6!

I check the Nutrition Facts labels for the B-6 milligrams of food that we're considering purchasing. Even 2 mg can have a powerful effect. I'm usually aware of where there's restroom when shopping or driving...
April 7, 2017

Hi Susan - We appreciate you comment. Interestingly, while some websites suggest that vitamin B-6 can act as a diuretic -- and that certainly seems to be your experience -- we are not aware of research substantiating this. Would you please let us know your source of your information for that effect? Thank you.

April 1, 2017

I have been taking Vitamin B-6 for a long time for "protein and energy metabolism" (Rite-Aid). The smallest tablet available in Pharmacies is 50 mg. I cut it in half and take one per day. Is that a danger to my health? Thank you.
Louis Rombach
April 1, 2017

You're okay doing that, Louis. It's still a lot more than you need but its not unsafe. See our information at

October 20, 2015

Is the UL the same for the Pyridoxine and P5P versions of B6?
October 21, 2015

Hi James - Please see the CL Answer we've now added about P-5-P, here:

Also see the "What to Consider When Buying and Using" section of the B Vitamin Supplements and Energy Drinks Review:

December 11, 2014

I have a condition in which B6 and its metabolites are destroyed in the body by a substance of unknown origin. With out supplementation in the 50-100 mg range daily I suffer the symptoms of severe deficiency even with normal diet-intake levels of B6.

T E 17769
April 18, 2019

What is this condition?

I can find no mention of any such thing in the medical literature. B6 deficiencies seem to be related to 1) malabsorption, so inflammatory bowel disease, celiacs, etc, 2) to the use of several medications, notably antituberculars, and 3) to alcohol excess.

Really, it seems from the literature that B6 excess may now exceed the incidence of B6 deficiency, primarily because of supplementation. If you look at LEF and search for B6, you get pages of supplements that contain supraphysiological amounts. If someone is innocently taking several of these, it would be easy to exceed the 100mg/d recommended safe limit. And you wouldn't even know you are taking it, if for example you simply wanted a joint supplement, a daily booster, a multivitamin, and a sleep preparation.

December 9, 2014

CL RECOMENDS 2-3 mcg FOR B12 BUT ALL THE B-12 SUPPLEMENTS HAVE 1000mcgs or more (16,000%) - WHATS UP WITH THAT???
December 15, 2014

Hi Gary - Please see our CL Answer about this here: You can also read more about taking B-12 here:

December 8, 2014

I also take one per day of the Life Extension "Two Daily". When I took two I had neurological symptoms - tingling in my legs and feet.

December 23, 2017

A friend in her mid 50's, very active and healthy ended up seeing the neurologist for balance problems. He diagnosed her with an overdose of Vit B6. It cleared up quickly when she stopped all supplementation. Her story prompted me to request a blood test for B6 because I was also having balance problems. My Dr. was surprised when it came back positive for too much B6. The culprit was 5mg of B6 in a melatonin supplement I was taking. Glad to see the recommended dose is being reduced.

May 13, 2018

I also got tingling in feet and legs with any B6 supplement.

December 8, 2014

Is there a difference when using Metanx which contains Folic Acid, B6 and B12. Below is a link to info on this product:


December 7, 2014

"The mega doses of vitamins found in some daily multis may be driven more by marketing considerations than science."

This is why I only take ONE per day of the excellent Life Extension "Two per Day" daily vitamin. You still get generous quantities of the ingredients with one tab compared to one tab of, say, Centrum (with the exception of Folic Acid, which is 200mcg per TABLET).

(Edited to change mg to mcg)

Susan 282
December 7, 2014

You should add that Vitamin B6 is a diuretic. If taken in the evening, one may have to get up to urinate a few times during the night. The so-called weak bladder or Prostate problem may not be that; but caused by Vitamin B6. Of course, a M.D. should determine the cause. But, it might be both a bladder problem & the diuretic.
December 9, 2014

Hi Susan - It is interesting that you report this effect. It has been noted on some websites, but we are not aware of any mention in the clinical literature of a diuretic effect of vitamin B-6.

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