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Pyridoxal-5-phosphate, sometimes called P-5-P or PLP, is the active form of vitamin B6 (pyridoxine). Most supplements provide the pyridoxine form of B6, although some provide pyridoxal-5-phosphate, or a combination of both. Taken at recommended doses, both forms appear to be relatively safe and have similar bioavailability for most people. Although pyridoxal-5-phosphate is sometimes promoted as more beneficial for people with diabetes, there do not appear to be any studies in people to support this. For more details, see the "What to Consider When Buying" section of the B Vitamin Supplements Review >>

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August 13, 2021

A friend of mine has been taking very high doses of vitamin B6 for over a year and has begun to experience
various neuropathies that became progressively worse. He became aware of the damage being done to his nervous system and stopped taking the vitamin. He noticed a marked improvement immediately. However, there was possible irreversable damage that might take years to reverse.
August 13, 2021

Yes, one can can too much vitamin B6 (pyridoxine), which can cause nerve damage, as well as skin lesions. This is discussed in detail (including upper daily limits for B6) in our B Vitamins Review here:

October 21, 2015

You are not taking into consideration the very real problem of people who have gene mutations which affect their methylation process. The bio-available forms of all B vitamins, especially Folic acid in the form of 5-Methyltetrahydrofolic acid, are a necessity for these people.
November 16, 2015

Hi Carol - As noted in the section of the B Vitamin Supplement Review linked to in the above answer, P-5-P may be prescribed for people with conditions that prevent the body from converting pyridoxine -- this would include people with certain genetic mutations.

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