T Nation

Zinc Amount


Hi guys,

I have a question. I do not understand a few things about supplementation, and I am hoping that you guys can help me out here. (I asked the pharmacists at the local pharma but they had no idea about it...)

For example, I bought a bottle of Zinc tabs from GNC. It is written on the back of it like this:

Amount per serving-------------% Daily Value

Zinc (as Zinc Gluconate) 50 mg 333%

What does that mean? That I have 50 mg of Elemental Zinc FROM Zinc Gluconate? ( Meaning that I would have about 500-600 mg of Zinc Gluconate?)
Or does that mean that I have 50 mg of Zinc Gluconate (Meaning that I would have about 7.5 mg of Elemental Zinc in it?)

Same with my Magnesium bottle from the same GNC.

Magnesium (as Magnesium Oxide and Magnesium Gluconate)-----------250 mg.

Does that mean that I have 250 mg of Elemental Magnesium FROM Oxide and Gluconate? Or I have 250 mg of Oxide and Gluconate? Which would make my elemental magnesium dose lower?

Thanks for your answers.


It should mean, and does mean unless they made an error, that you have those amounts of the elements.


Got it, thank you very much!


You’re very welcome!


Incorrect! Only 13% of zinc gluconate is elemental zinc. So one 50mg of that will give you only 6.5mg of zinc. I laugh when someone says they are taking 100mg supplent of zinc gluconate (for example) and then the rest of the thread is people freaking out and telling them they are going to overdose lol. Its only 13 mg of elemental zinc, elemental zinc is what is being used by the RDA when you see the requirements. Upper tolerable limit is 40mg, so 2 of those dont even put you close to that.

Zinc picolinate I have had a hard time finding the % for though. Does anyone know? I saw somewhere 21% elemental but im not sure how accurate that is. In particular, I am wondering about the Now Foods brand, if that makes a difference.


I suggest re-reading the original post and label. It is not 50 mg of “zinc gluconate” but 50 mg of “zinc.” The parenthetic describes the source.

If you wish to calculate a percentage for a form of zinc or any element, the way you do it is first to find the molecular formula and see how many atoms of the element are in the compound. (It will typically be 1, but not necessarily.)

Then find the atomic weight of the element.

Then find the molecular weight of the material.

Divide the atomic weight by the molecular weight, then multiply by n (if it’s not 1) and that is your fraction that is the element.

If desired, multiply by 100 and that’s your percentage.


Further, as the label reads 333% of Daily Value, and the DV is 15 mg/day of zinc for adults, it follows that the zinc content is 50 mg, as the label says.


In his post he says 50 mg Zinc (as Zinc Gluconate)

Doesnt this mean its 50 mg of Zinc Gluconate?

Wait nevermind I see what you’re saying, but this seems to go against everything ive been reading…or ive been misunderstanding it.

So if i am understanding right, he is actually taking roughly 240mg of Zinc gluconate, even though this number isnt actually on the bottle? Correct?


So going back to my question, when my label says, "50 mg Zinc (from Zinc Picolinate)…this is actually 50 mg elemental? Maybe I should stop taking 2 lol.

But why do they sell 50mg amounts of elemental zinc when the upper limit is 40? That doesnt make sense. Im so confused now lol


Yes, if correctly labeled it will be 50 mg of elemental zinc. I indeed would not take 2.

If I thought I had a zinc deficiency, I might take 1 a day for a time to help build back up.

The dosage indeed is higher than should be taken longterm on a daily basis.

On why they do it, it could be for the above reason if the label gives any such advice, or it could be just another of those things that various nutritional supplement companies do for which there’d be no hope of finding a good reason.


Thanks! (sorry for the rather jerkish “incorrect!” in my first post btw lol)

Ill go back to 1. I only just started taking 2 50mgs a couple days ago after switching from Gluconate to Picolinate, which i read is better absorbed since I do feel I have a deficiency. I have some of the symptoms especially the slow wound healing. I also have stretch marks that are well over 10 years old and still have not faded to the silvery white that everyone claims they do over time (the ones on my side are almost 20 years old!), mine are still darkish pink. I dont know if thats attributed to a zinc deficiency but its a decent suspect Im thinking.


You’re welcome! No problem! :slight_smile:


Exactly the same thing that i was wondering. For you to understand just how dumb these people in the medical industry are, realise that I have asked a doctor the same thing and she had no idea. My fucking god, and these people are supposed to have our health in their hands?

I upped the dose one day to 100 mg zinc gluconate (which i hope is 100 mg zinc from 500 or so mg of gluconate) and I have felt a few days a better morning wood, better nightime erections, waking up with very high libido but after a few days I guess my body adjusted to it because I stopped feeling these extra things. Now my bottle is finished so I will buy a new one but I think of taking only 50 mg/day.

Also another doctor told me to look at the sheer size of the tablet. I compared my 10 mg Nolva tablet to my 50 mg Zinc tablet. The zinc tablet is huge, closer in size to a 500 mg Paracetamol which means that it has a 500 mg weight. It is 500 gluconate or something like that which leads to 50 mg Elemental zinc so yep Bill was right.

In your opinion, what are the most important supplements that a person nowadays should take? I heard that it’s Magnesium, Zinc and Vitamin D3, these being the most widespread deficiencies in the modern world…


Crazy idea - why don’t you just take ZMA or Elitepro Pro made by Biotest?! Personally, I take Elitepro each night along with a couple Z-12 pills.


I’d agree with magnesium, zinc, and D3 as being the first I’d pick in terms of both commonness and importance, and would add iodine and Vitamin K to that.

On your personal supplementation, long term, I wouldn’t consume 50 mg/day zinc, but for a few weeks to deal with a deficiency it could be fine.

For a fuller view of what’s common in deficiencies, a 2011 study found these resuts. The numbers are the percentages of Americans falling below the “estimated average requirement,” which is the DV figure adjusted to account for probability of being of a given age or gender. The results are for intake from the food itself, from that plus enrichment (flour-containing products, reduced fat milk, various cereal products etc, and that plus nutritional supplementation:

Vitamin D
Naturally occurring 100

  • Enriched/fortified 93.3
  • Dietary supplements 69.5
    Naturally occurring 54.2
  • Enriched/fortified 48.9
  • Dietary supplements 38.0
    Vitamin A
    Naturally occurring 74.4
  • Enriched/fortified 45.1
  • Dietary supplements 34.0
    Vitamin C
    Naturally occurring 45.9
  • Enriched/fortified 37.0
  • Dietary supplements 25.3
    Vitamin E
    Naturally occurring 93.3
  • Enriched/fortified 90.7
  • Dietary supplements 60.3
    Naturally occurring 50.9
  • Enriched/fortified 5.9
  • Dietary supplements 4.3
    Naturally occurring 8.7
  • Enriched/fortified 2.1
  • Dietary supplements 1.6
    Naturally occurring 11.3
  • Enriched/fortified 1.7
  • Dietary supplements 1.2
    Vitamin B-6
    Naturally occurring 21.7
  • Enriched/fortified 12.3 6
  • Dietary supplements 8.2
    Vitamin B-12
    Naturally occurring 6.0
  • Enriched/fortified 3.2
  • Dietary supplements 2.3
    Naturally occurring 88.0
  • Enriched/fortified 10.7
  • Dietary supplements 7.6
    Naturally occurring 5.9
  • Enriched/fortified 5.5
  • Dietary supplements 5.3
    Naturally occurring 58.9
  • Enriched/fortified 54.5
  • Dietary supplements 44.8
    Naturally occurring 21.8
  • Enriched/fortified 6.5
  • Dietary supplements 5.0
    Naturally occurring 15.2
  • Enriched/fortified 10.5
  • Dietary supplements 8.0
    Naturally occurring 4.8
  • Enriched/fortified 4.3
  • Dietary supplements 3.7
    Selenium, mg/d
    Naturally occurring 0.9
  • Enriched/fortified 0.9
  • Dietary supplements 0.7
    Naturally occurring 2.2
  • Enriched/fortified 2.4
  • Dietary supplements 2.5 (sic)
    Vitamin K
    Naturally occurring 30.1
  • Enriched/fortified 31.1
  • Dietary supplements 35.3 (sic)

I don’t know why they neglected iodine.

So quite a large number of nutrients have a substantial percentage of Americans falling below the DV. This is from the poor quality of chosen food, rather than it being difficult for DV to be achieved with a good diet.