These two Vitamin B Complex supplements contain doses that differ by a factor of as much as 70 times.

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How much, if any, supplement is good for you? That depends of course on you, your diet, your size and many other things. We can't give specific nutrition advice here.

However, these are both supplements aimed at adults with a daily dose of one capsule. If you can modify the dose by 70 times, is it not safe to say that it makes no difference how much you take? Perhaps the smaller dose is adequate and the larger dose is unharmful. Perhaps the smaller does is akin to placebo, and the larger dose is required to provide any benefit that might be required? Perhaps it truly makes no difference, you can take none or you could take a whole bottle daily with no positive or negative effects either way.

It is interesting that both of these product far exceed the %DV recommendations. How does one market a vitamin supplement with 8000% the FDA recommended daily dose? Surely that creates a huge overdose liability. ... unless, in fact, it really makes no difference how much you take so long as you are not malnourished.

How can one make sense of what is nutritionally relevant/helpful/required if there is such a wide range of “normal” products available?

  • 1
    Supplements are very weakly regulated in the US. Most have absolutely zero evidence of any benefit, though the manufacturers have wide leeway to advertise otherwise.
    – Bryan Krause
    Commented Oct 31, 2021 at 14:46
  • 1
    I wouldn't believe either of those labels are accurate until I saw an analysis by a reputable independent lab. And I wouldn't be surprised if they both contain contaminants.
    – Carey Gregory
    Commented Oct 31, 2021 at 16:37
  • But this is a good question that needs a good answer.
    – Carey Gregory
    Commented Oct 31, 2021 at 22:29
  • @CareyGregory "not accurate", do you mean that aside from being ridiculously inconsistent in the size of their dose, you think they also do not contain the stated doses? That actually would surprise me a little. These are both from big name brands, all they have to do is faithfully manufacture whatever nonsense they put on the label to maintain their reputation. I'd be surprised if they didn't meet their own meaningless standards.
    – jay613
    Commented Nov 1, 2021 at 11:46
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    Yes, unless there's a USP certification on the label, I mean they may not contain the stated quantities. Supplement manufacturers are free to seek USP certification, but few of them do. There's a reason for that.
    – Carey Gregory
    Commented Nov 1, 2021 at 18:11

1 Answer 1


Although those 100mg numbers seem huge (compared to the 1.5-2 mg in the other product) there's no established toxicity level for most subtypes of vitamin B. And from the little more concrete data that exists for B6, one US institution (NAM/IoM) sets the limit at 100mg/day, although others elsewhere have set it lower, e.g. 10mg/day by the UK's NHS.

  • Toxicity? Interesting. Aligns with one of my (slightly flippant) theories, that 1) if you are not malnourished you don't need any supplement, 2) if you need some, you probably need somewhere around the FDA DV, or at least that's a data point to guide you, and 3) if you take 70X the amount it won't quickly and directly kill you but aside from that benefit, who knows.
    – jay613
    Commented Nov 1, 2021 at 11:44
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    @jay613 Not commenting on these particular supplements, but for some people who do need a supplement for some vitamin or mineral it's because they have a deficient uptake, so indeed they may need an oral dose far above what a typical diet would include. But that's for a doctor-prescribed situation. There's little to no scientific support otherwise that any supplements do anything at all.
    – Bryan Krause
    Commented Nov 1, 2021 at 14:37
  • @BryanKrause Food is fortified(cereals and milk), mandated by the state, especially for pregnant women to prevent certain diseases in newborns? Seems like there does exists science to support dietary supplementation.
    – paulj
    Commented Nov 9, 2021 at 14:24
  • @paulj I'd lump that in with the doctor-prescribed/doctor-recommended variety. The vast majority of supplements found in the store do not fall in that category and do not support a broad claim like "support dietary supplementation"; it's the exception that proves the rule.
    – Bryan Krause
    Commented Nov 9, 2021 at 14:30
  • @jay613 One reason supplements are helpful nowadays is that the liver is depleted of vitamins in its work of breaking down toxins, and toxins are all around us these days. Think of cigarette smoke, vehicle exhaust, acid rain, insecticides, chemical food additives, etc. It used to be that food would provide all the vitamins one needed; but now it provides toxins, too, that deplete the body's vitamin reserves, and our dietary requirement for vitamins is increased.
    – Polyhat
    Commented Nov 29, 2021 at 7:14

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