Posted by Larry Hoover on June 1, 2003, at 9:17:28
In reply to Larry, Zinc/Selenium/Vitamin C questions, posted by Caleb462 on June 1, 2003, at 0:11:26
> Hey Larry.
Hey.
>Okay, well tonight I went out and bought some selenium and zinc. I also had my heart set on some niacinamide, but couldn't find it - I'll look some more tommorow.
I've occasionally seen it marketed as no-flush niacin, rather than being labelled as niacinamide. No-flush niacin might also be inositol nicotinate, so you have to check the ingredients.
> The zinc is zinc gluconate, and the selenium is selenium yeast. Are these adequate forms of the minerals?
Yes, they're what I use.
>I don't want to be taking the zince and selenium equivalents to magnesium oxide, if you know what I mean.
Absolutely. I hear ya.
> Now, what about dosages? The zinc tabs are 50 mg, the selenium ones are 200 mcg. How much zinc and how much selenium are needed for a benefit in mental/emotional well-being? I already get 15 mg zinc in a daily multi-vitamin, plus 200 mcg selenium, I believe. Will it be safe to add these supplements?You would exceed the tolerable upper limit on zinc if you took one tablet a day, in addition to your multi, but a more cautious dosing would be one additional tablet every other day. I often take 80 mg, but I don't take it every day. You want to look at the "running average" of your intake, over time. Kind of like, how much did I get altogether in the last two weeks, and divide that by 14 to get the average intake. The National Academy of Sciences puts a TDI (tolerable daily intake) at 40 mg/day, but if you really get into the statistics and assumptions (I've spent some major time on this), you'll find that the conclusions are massively biased by an attitude something like, "We have to set the level so low that nobody could ever get hurt by this". The zinc tablets you bought should be illegal or something, if the TDI was valid, wouldn't you think? Every day on the news, you'd be hearing about more "sporadic cases of zinc poisoning", or some such, wouldn't you think? Like I said, the TDI is set at a level that ensures that virtually no one could get hurt, rather than at levels which ensure optimal intake for treatment of special populations. Moreover, intake does not mean the same thing as uptake. If you don't absorb or retain minerals well (I am certain I don't), then intake is the only way to compensate. That's ***my*** reality. You've got to learn how to responsibly assess yourself.
Check the label on your multi. Does it say selenium as selenate or selenite? If so, the selenium in the multi is less useful to you, meaning the effective amount of selenium is much less than the total amount they're claiming.
Selenium is toxic at levels of much greater than 1 gram per day over very long periods of time, leading to a disorder called selenosis. It happens in places in Asia where the water supply is naturally full of selenium, for example. In studies of those people, already overloaded with selenium, their symptoms abated if they could get the selenium intake down below something like 870 micrograms (0.87 grams) per day. So, that's where the tolerable upper intake of selenium of about 400 micrograms/day comes from. I think a one-month trial at 600 micrograms would be safe. You'll be coming at the 870 microgram level from the "other side", ya know?
If you want to read the Academy of Sciences reference books, they're available online at:
http://search.nap.edu/nap-cgi/napsearch.cgi?term=Tolerable+Daily+Intake
Just scroll down the page until you find the nutrient you want to study, and click on it (or the book in which it's listed, which will let you click on the index).
> Also, what exactly are the roles of zinc and selenium in the body, and how do they contribute to mental health?Zinc is primarily a structural component of specialized proteins, like enzymes. Selenium does that as well, but it also has a major function in antioxidant protection (especially in the brain). Zinc has a minor, but not inconsequential, role in the latter context.
Without zinc, no neurotransmitters. Without selenium, no functioning neurons. Gross simplification, but that's the idea.
> Finally... about vitamin C. I get around 90 mg in my daily multivitamin (can't remember the exact number), 500 mg in my daily B-complex + C, and now, I'll be getting an extra 100 mg that is included in the selenium tabs. Not to mention that I drink a lot of orange juice, and probably get another 50-200 mg of Vit. C from that, depending on the day. Is this too much C? Can it do any harm?
No, not too much. Probably still too little. Here, there is no concern about upper intake levels. Vitamin C has no identified toxic effects, except for diarrhea if you take too much all at one time (without letting your body adapt). If you have been taking large amounts for a period of time, sudden reduction of that dose can lead to symptoms of scurvy, because you become dependent on it. There is a balancing act, here.
I'd say a minimum target ought to be 2 grams per day, for all psychiatric populations. Mental illness is stressful, and stress whacks vitamin C, hard. Vitamin C helps protect against stress, so you get a vicious circle if you get behind on your C. I think you get the best effect if you shoot for 2 grams a day, and have brief periods of higher intake. Your body won't become dependent on the higher dose, yet you still get the enhancements.
Just to put vitamin C doses in a perhaps novel context, I was just reading an article yesterday that was suggesting vitamin C as a possible therapy against SARS. There is no therapy, at present. And SARS is a wicked virus, with major long-term systemic effects. Anyway, the suggested therapy involves daily intravenous infusion of 120-180 grams of vitamin C. Some doctors are claiming that they are able to block the development of mononucleosis (Epstein-Barr virus) with timely vitamin C supplementation at 10-20 grams/day.
> Thanks a bunch, Larry. You are a treasure to this board.
Thanks for helping me feel like a treasure.
Lar
poster:Larry Hoover
thread:230511
URL: http://www.dr-bob.org/babble/20030530/msgs/230546.html