Is 4g vit c a day safe to take??

Anthony/CS? Thanks!

Its kind of a controversial subject. If you ask Linus Pauling, he'd probably say it was totally safe. I believe that at one point he was taking 20-30 g daily, and lived to the ripe old age of 93.

We can probably assume that there is an upper limit for health reasons, as vitamin C in too high of amounts actually contributes to oxidation. So the negative effects may not be acute for some, but from a practical standpoint, going above a certain amount might just be counterproductive to what you are trying to achieve in the first place, which is an antioxidant effect. The adverse effects of too high of intake that you would notice are almost strictly gastrointestinal (if one experiences them at all). You'd get stomach cramps and diarrhea. That's probably one way of telling if your dose is too high.

A study out of Cornell from some years ago tested the body's capacity to absorb vitamin C. They found that there is a relative limit and it depends on how high the dose is, i.e. there are diminishing returns. Once you hit a certain gram/day dose, you actually start absorbing less of it so its counterproductive.
A 5g/day dose was absorbed at a rate of 35%, with the rest being excreted in urine. At 10g/day in two divided doses, total absorption dropped to around 25%. Some people will absorb more, some less. I'd imagine Linus, even if he was at the high end of the distribution, was probably only absorbing 3-5 grams of what he was taking each day.

According to the author, the limit of absorptive capacity of the human intestine for vitamin C is reached at about 3 g per day. 4 grams daily is probably safe. But for me, its an issue of usefulness. 500mg-1000mg doses taken with meals 3 meals a day should be just fine.

I believe A < R was doing around 4 grams daily, and said good things about this.

Thanks anthony. The reason I ask is because there is another individual I know taking around 9 grams MSM daily with 4 g vitc and he has noticed substantial thickening of his hair over 4-5 months. I am already taking 2 g vit c daily and wanted to increase to 4 but was worried about side effects such as kidney stones, which is well documented with vit c toxicity. Some various sources on the net claim above 2g daily could be considered toxic for some so I wanted to check here with you guys.

I'm currently taking about 6 gm of C/day along with an equivalent amount of MSM and I too am noticing thicker hair. C and MSM are a great combo!

No need to be concerned about safety.

http://www.doctoryourself.com/vitaminc.html

[excerpt]

Vitamin C is remarkably safe even in enormously high doses. Compared to commonly used prescription drugs, side effects are virtually nonexistent. It does not cause kidney stones. In fact, vitamin C increases urine flow and favorably lowers the pH to help keep stones from forming. William J. McCormick, M.D. used vitamin C since the late 1940's to prevent and treat kidney stones. Vitamin C does not significantly raise oxalate levels, and uric acid stones have never resulted from its use, either. Said Dr. Klenner: "The ascorbic acid/kidney stone story is a myth."

How much vitamin C is an effective therapeutic dose? Dr. Klenner gave up to 300,000 milligrams (mg) per day. Generally, he gave 350 to 700 mg per kilogram body weight per day. That is a lot of Vitamin C.

But then again, look at that list of successes.

Dr. Klenner emphasized that small amounts do not work. He said, "If you want results, use adequate ascorbic acid (Vitamin C)."

Keep in mind of imbalances when a large amount of a nutrient is consumed.

So in the case of vitamin C, some may (not all) need additional bioavailable copper.

In cases of large doses of MSM, molybdenum should be added (since it can be depleted).

Hm, wasn't aware of the MSM/molybdenum issue, thanks.
I did a search and found a product that combines them: http://www.seekinghealth.com/msm-vitamin-msm-supplement.html

I see that my diet is pretty rich in molybdenum. Peas, liver, greens. But I'll check out that product.

I am taking blackstrap molasses which I think will provide enough copper to balance the C.

Hey CS, thanks for the info. Are there any good resources you know of that lay out these types of relationships. It would be nice if there was some resource that aggregated it all so that you could just look up a nutrient and see how other nutrient levels are effected by it.