Is it possible to OD on vitamins

Woofer

I have been battling a cold for the last few days. My friends "Super Health" book suggests taking 2 grams of vit c & 50g of zinc every 4 hrs (ie: 3 times a day) when you have a cold/flu. This means that I am taking approximately 9000% the Recommended Daily Allowance of vit C and 1000% RDA of zinc. Is this bad for me? So far, after 3 days I am starting to feel better (no way of knowing how much of this if any is attributable to my heavy dosage of vitc/zinc) and have not noticed any bad side effects.
Any opinions?

EileenG

50g of zinc? That has to be a mistake.

The RDA for Vitamin C is a joke, it's the amount you need not to get scurvy, nothing like the amount you need for good health. You can safely take 2g a day of Vitamin C and the worst that will happen if you are taking more than you need is that you'll get loose stools, though you normally need a much higher dose before that happens.

I normally take 1g a day for general good health. I've had a lot of dental work done recently, so I'm now taking that twice a day. My dentist approves.

It's possible to overdose on zinc, but there's a handy way to know when you've had enough. If you can taste it, you don't need it. If you let it melt on your tongue and there is no taste, you are deficient.

The one to really watch for overdose is iron. The toxic level is quite low, and iron is already put into a lot of food, especially cereals. Two bowls of Special K can put you over the daily limit. If you take an iron supplement on top, you are at risk, and haemochromatosis is very common in Ireland.

Woofer

Thanks for the advice interesting about iron. Will have to check that out.

I can't taste the zinc. what's it supposed to taste like? :pac:

_Whimsical_

EileenG wrote: »

It's possible to overdose on zinc, but there's a handy way to know when you've had enough. If you can taste it, you don't need it. If you let it melt on your tongue and there is no taste, you are deficient.

That's very interesting. I didn't know that.

Woofer wrote: »

I can't taste the zinc. what's it supposed to taste like? :pac:

Zinc is a metal so I'd say it would taste metalic and bitter.

Mellor

I imagine its possible to overdose on all vitamins. Obviously the threshold for some might be quite high (vit C for example).
Its even possible to overdose on water,

lizzyvera

You can overdose on vitamins and minerals.
Also, Vitamin C for colds is a placebo. Hate to tell you because it won't work now, but it has not been shown to be more effective than placebo.

For a cold I'd recommend sudafed (clears out your nose and sinus), olbas oil to inhale (it's like strong Vicks), TCP antiseptic to gargle to help with sore throat, soluble paracetamol like solpadine to gargle for sore throat and also swallow for headache. Rest and patience also help.

El_Dangeroso

Water soluble vitamins (All the B's and C) can be excreted in your urine, hence the frightfully luminous colour of your pee after taking a b complex. This makes them nearly impossible to OD on and vomiting would kick in far sooner than you could.

As regards the fat soluble vitamins (A, D, E and K), although it is possible to overdose (hypervitaminosis) the RDA's are ridiculously low.

Regarding D in particular, you need 5,000IU or more at this latitude to maintain healthy blood levels, but the RDA is a paltry 400IU, only barely enough to prevent rickets, not all the other myriad diseases cause by low blood levels. Toxicity of Vitamin D occurs at 30,000IU or more daily. Having said that there was a man who bought D3 pills that contained 1 million IU :eek:, he took them daily and did get sick but recovered quickly and fully after steroid treatment.

There is a lot of controversy about vitamin A, that high doses can lead to osteoporosis, but this only occurs when vitamin D blood levels are low, when they are optimal, no toxic effects are observed even at pharmacological doses of the vitamin.

Regarding Vit C and colds, all the random controlled studies show that although it has some role in preventing colds, it doesn't shorten the duration significantly. Echinacea, ginseng and most over the counter pharmaceuticals, including sudofed do no better than placebos in shortening the duration of a cold.