Vitamin B6 and nerve damage: reading the ceiling, not the floor

Exhibit 01

The sentence that has to come first

One sentence comes first, because a careless page here would do real harm. Nothing on this site says or implies that this bottle will damage anybody’s nerves. The intended 1.7 mg is about one 59th of the Tolerable Upper Intake Level, and the amount printed on the panel is a thousandth of that again.

That is not a disclaimer attached to the end of a frightening page. It is the finding, and the rest of this post is the arithmetic behind it.

So why publish any of it. Because this is a nerve product, and vitamin B6 is the one ingredient here that a federal source affirmatively connects to causing the condition the product is sold for. A page that left that out would be leaving out the most relevant thing the federal record holds about anything on the label.

And because of one printed figure. The panel prints vitamin B6 at 100% of the Daily Value. A reader who takes that at face value has been told their B6 is handled.

Exhibit 02

What NIH actually publishes, in its own words

Four sentences, quoted rather than summarised, because a paraphrase of this material is where the distortion gets in. All four are from NIH Office of Dietary Supplements.

Read the figures in the clinical sentence, because the figures are the whole of it. Grams a day, for a year to more than three years. A gram is a thousand milligrams. That is the exposure the sensory neuropathy literature describes, and the reason a ceiling exists.

The last quotation is one a page could easily leave out, and leaving it out would change the impression the others create. It says the symptoms usually stop, not always.

None of those sentences is a statement about Nerve Recovery Max. Every one is about vitamin B6 at doses this panel does not approach. This site never cites PubMed or PMC as a federal finding: the National Library of Medicine runs that index, and an entry in it is not an agency position.

Exhibit 03

The ceiling, and how it was arrived at

A Tolerable Upper Intake Level is not a dose and not a target. It is the figure above which an agency is no longer willing to describe daily intake as tolerable, and it applies to everything a person takes together.

For vitamin B6 in adults it is 100 mg a day, and NIH ODS describes the step that produced it: “the FNB halved the dose used in these studies to establish a UL of 100 mg/day for adults” ^{NIH ODS} Read that as arithmetic on the harm literature rather than a finding of its own. Two other published figures belong beside it, because a ceiling alone tells a reader nothing about where they are standing.

What makes the ceiling worth knowing is not its height but the fact that it is a sum: it applies to diet, to a multivitamin, to a B-complex and to a nerve product added together, and no one of those labels can tell you what the others hold.

Exhibit 04

Where this bottle actually sits

Now the arithmetic, which is the reason this post can be written without alarm.

The intended amount here is 1.7 mg, which is the Daily Value itself. Against a ceiling of 100 mg that is about one 59th, inside the ordinary adult intake NIH ODS publishes of 1.3 to 2.0 mg a day. A reader would have to take about 59 servings a day of the intended amount to reach the ceiling from this product alone.

The amount printed is 1.7 mcg, one thousandth of that again, which puts the ceiling about 59,000 servings away. The label wins on what it says; the regulation wins on what the unit means. 1.7 mcg against a 1.7 mg Daily Value is 0.1%, which rounds to 0% - not the 100% printed beside it.

Neither figure is anywhere near the doses in the harm literature, and this post says so as plainly as it quoted the harm sentence. What there is on this panel is a printed percentage of 100% against a unit that cannot support it, and that is a separate finding with its own post. The label page

Exhibit 05

The cupboard, not the bottle

Here is the part worth taking away, and it is not about this product.

The reader this material protects is the one who buys a nerve product, keeps taking a multivitamin, adds a B-complex because a forum recommended one, and counts none of it. Nothing on any of those panels is wrong. The sum is where the figure lives, and no panel computes a sum.

1. Write down every product you take that names a B vitamin

   Multivitamins, B-complexes, energy products, nerve products and fortified drinks. The vitamin does not have to be the headline ingredient to be on the panel.

2. Read the amount, not the percentage

   A percentage is a comparison with a reference figure. Two labels can print the same percentage and different amounts, and only the amounts add up.

3. Add the amounts, in one unit

   Milligrams, since that is the unit the reference table uses for vitamin B6. Watch for micrograms, which are a thousandth of the same figure.

4. Compare the total with the published ceiling

   100 mg a day for adults, from all sources together. Then take the list to somebody who can read it with you.

A label printing a vitamin at 100% of the Daily Value makes that worse rather than better, because a percentage of a hundred reads as handled. The label page is why that particular percentage cannot be taken at face value.

NIDDK owns this condition and publishes the sentence these pages treat as the most important on them: “For safety reasons, talk with your doctor before using supplements or any complementary or alternative medicines.” ^NIDDK Peripheral neuropathy has causes that need diagnosing, and some of them are treatable.

The cautions page carries every published caution for every named ingredient here with the printed amount beside each, and who it is for sets out the groups the sources tell to ask first.