# What's up with Vitamin C? **URL:** \ **Category:** Factual Questions\ **Created:** [September 12, 2009, 1:25pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817 "2009-09-12T13:25:48Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Cat\_In\_A\_Top\_Hat](https://avatars.discourse-cdn.com/v4/letter/c/f6c823/32.png) [@Cat\_In\_A\_Top\_Hat](https://boards.straightdope.com/u/Cat_In_A_Top_Hat)\ **Post date:** [September 12, 2009, 1:25pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/1 "2009-09-12T13:25:48Z")
So I noticed that just about all of the sport/energy/health drinks seem to have at least 100% of the recommended daily allowance of Vitamin C in them, these days. Some have two or three times that. Despite this, they tend to have much less of other vitamins in them. What is it about Vitmain C that makes it so easy or feasable to put into things in such comparably large amounts? Or is it just that one doesn’t need much of it to meet the RDA? Thanks, –CiaTH ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [September 12, 2009, 2:13pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/2 "2009-09-12T14:13:20Z")
Vitamin C tastes good. ---
**Author:** ![foolsguinea](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foolsguinea/32/14751_2.png) [@foolsguinea](https://boards.straightdope.com/u/foolsguinea)\ **Post date:** [September 12, 2009, 2:51pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/3 "2009-09-12T14:51:18Z")
And it’s water-soluble, so if you ingest a lot of it, it’ll just flush out easily. Might make you a little too acidic for a while. ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [September 12, 2009, 3:05pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/4 "2009-09-12T15:05:30Z")
There was some big hubub about vitamin C being a cure-all. Was before my time, though. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [September 12, 2009, 3:21pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/5 "2009-09-12T15:21:46Z")
Vitamins A and D are toxic in megadose quantities, i.e., multiple times the RDA. For D in particular the healthy range between “too little” and “dangerously too much” is relatively narrow. Except thiamine (B-1), excessive quantities of the B vitamins are not known or theorized to provide any health benefits beyond those the RDA provides, and excesses of these water-soluble vitamins are excreted. C, on the other hand, is different. Toxicity level is quite high (meaning there’s a wide safe range) and some people report increased resistance to, and more rapid recovery from, viral infections such as the common cold and influenza from taking it in quantity. AFAIK, tests of this claim are at best inconclusive, but there remain a group of people who are apparently sincere in their anecdotal claim that it helped them. Needless to say, the whole subject of “vitamin therapy” is hotly debated. I would say the majority of medical practitioners would call it bullfeathers, or at best non-proven. But there is limited, anecdotal evidence that for some people and some ailments, higher-than-needed doses of water-soluble vitamins, particularly C, has some health benefits. ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [September 12, 2009, 3:49pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/6 "2009-09-12T15:49:13Z")
> [@Polycarp](#): > > For D in particular the healthy range between “too little” and “dangerously too much” is relatively narrow. I think you’re mistaken there. From wiki: > [@](#): > > In 1997 the U.S. Dietary Reference Intake Tolerable Upper Intake Level (UL) of vitamin D for children and adults was set at 50 micrograms/day (2,000 IU), but this is viewed as outdated and overly restrictive. A 2007 risk assessment suggested that 250 micrograms/day (10,000 IU) in healthy adults should be adopted as the tolerable upper limit… In adults, sustained intake of 2500 micrograms/day (100,000 IU) can produce toxicity within a few months. 10,000 IU is 25x the RDA sustained over time. Also, noone is putting megadoses of C into drinks, but everyone loves to adverise how their drink has “100% of it.” Frankly, drinks should have 100% of a lot of other things too… And getting 100% (or a bit extra) of all your vitamins and minerals is NOT “hotly debated”! ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [September 12, 2009, 4:03pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/7 "2009-09-12T16:03:14Z")
> [@Alex\_Dubinsky](#): > > I think you’re mistaken there. From wiki: > > 10,000 IU is 25x the RDA sustained over time. > > Also, noone is putting megadoses of C into drinks, but everyone loves to adverise how their drink has “100% of it.” Frankly, drinks should have 100% of a lot of other things too… And getting 100% (or a bit extra) of all your vitamins and minerals is NOT “hotly debated”! You’re right. But you misinterpreted my comments. First, regarding Vitamin D: The “safe range” for D is from 1X to 5X the RDA. That’s what I meant by “relatively narrow.” That toxicity shows up at 25X is irrelevant – it’s fat-soluble, so it tends to accumulate if consumed at higher-than-needed doses on a consistent basis. Second, there is absolutely no question, as you say, that getting one’s RDA, or at least MDA, of all vitamins is necessary to continued good health. What I meant was “hotly debated” was “vitamin therapy,” i.e., the claimed practice of giving megadoses of vitamins, particularly C (and often E), for additional health benefits, including incrreased resistance/improved recovery from viral infections. By all means, people should get their RDA for good health. But it’s highly questionable if doses at multiples of the RDA have any benefits beyond what one gets from the RDA. That’s what I intended to convey by that comment. By the way, thanks for the disagreement – without it, I would not have realized how easily what I said could have been misunderstood, and would be guilty of “Handy posting” – giving false information on health matters, though inadvertently. ---
**Author:** ![Khadaji](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Khadaji](https://boards.straightdope.com/u/Khadaji)\ **Post date:** [September 12, 2009, 4:05pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/8 "2009-09-12T16:05:55Z")
> [@Polycarp](#): > > Vitamins A and D are toxic in megadose quantities, i.e., multiple times the RDA. For D in particular the healthy range between “too little” and “dangerously too much” is relatively narrow. \ Not according to [**Reinhold Vieth**](http://www.ajcn.org/cgi/content/full/69/5/842) > [@](#): > > Throughout my preparation of this review, I was amazed at the lack of evidence supporting statements about the toxicity of moderate doses of vitamin D. Consistently, literature citations to support them have been either inappropriate or without substance. The statement in the 1989 US nutrition guidelines that 5 times the RDA for vitamin D may be harmful ([3](http://www.ajcn.org/cgi/content/full/69/5/842#R3)) relates back to a 1963 expert committee report ([5](http://www.ajcn.org/cgi/content/full/69/5/842#R5)), which then refers back to the primary reference, a 1938 report in which linear bone growth in infants was suppressed in those given 45–157.7 µg (1800–6300 IU) vitamin D/d ([119](http://www.ajcn.org/cgi/content/full/69/5/842#R119)). The citation is not related to adult nutrition and it does not form a scientific basis for a safe upper limit in adults. The same applies to the statement in the 1987 Council Report for the American Medical Association that “dosages of 10,000 IU/d for several months have resulted in marked disturbances in calcium metabolism…and, in some cases, death.” Two references were cited to substantiate this. One was a review article about vitamins in general, which gave no evidence for and cited no other reference to its claim of toxicity at vitamin D doses as low as 250 µg (10000 IU)/d ([120](http://www.ajcn.org/cgi/content/full/69/5/842#R120)). The other paper cited in the report dealt with 10 patients with vitamin D toxicity reported in 1948, for whom the vitamin D dose was actually 3750–15000 µg (150000–600000 IU)/d, and all patients recovered ([121](http://www.ajcn.org/cgi/content/full/69/5/842#R121)). If there is published evidence of toxicity in adults from an intake of 250 µg (10000 IU)/d, and that is verified by the 25(OH)D concentration, I have yet to find it. Michael Holick, Ph.D., M.D., is the Professor of Medicine of Physiology and Biophysics at Boston University School of Medicine says: > [@](#): > > You can definitely overdose on vitamin D, but you have to take huge amounts of vitamin D to do so. Usually, you have to take more than 10,000 units of vitamin D a day for at least half a year before you even have to begin to worry about vitamin D intoxication. Now the normal range for the 25-hydroxy vitamin D is 30 to 100, but you could easily go even up to 150 because we see lifeguards that are outside all the time, making lots of vitamin D. They are at 125 nanograms per milliliter. They are not vitamin D toxic. So vitamin D is relatively safe, but you do have to be careful, and you don’t want to overdose on vitamin D. There is more and more research that many of us are D deficient and that current recommended doses are too low. Also B1 is not the only B to worry about: B6 can be dangerous - I’ll let you do the Google yourself, but from one site: > [@](#): > > Too much vitamin B6 can result in nerve damage to the arms and legs. This neuropathy is usually related to high intake of vitamin B6 from supplements, [[28](http://ods.od.nih.gov/factsheets/vitaminb6.asp#en28)] and is reversible when supplementation is stopped. According to the Institute of Medicine, “Several reports show sensory neuropathy at doses lower than 500 mg per day” [[12](http://ods.od.nih.gov/factsheets/vitaminb6.asp#en12)]. As previously mentioned, the Food and Nutrition Board of the Institute of Medicine has established an upper tolerable intake level (UL) for vitamin B6 of 100 mg per day for all adults [[12](http://ods.od.nih.gov/factsheets/vitaminb6.asp#en12)]. “As intake increases above the UL, the risk of adverse effects increases [[12](http://ods.od.nih.gov/factsheets/vitaminb6.asp#en12)].” ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [September 12, 2009, 4:24pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/9 "2009-09-12T16:24:25Z")
Hmmmm… I was trying to answer the basic question about “What are people claiming about Vitamin C, and is there anything real to it?” using such information as I thought I had. Apparently research has gone on beyond what I thought I knew. Probably it would be best for someone with medical expertise, like the **Chief Pedant** or **Qadgop** , to comment based on current research. My apologies for any false information I may have purveyed. ---
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [September 12, 2009, 4:57pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/10 "2009-09-12T16:57:28Z")
As others said, it’s very difficult to ingest so much Vitamin C that you overdose on it. So it makes a great marketing ploy. Vitamin C is a cure all for the common cold, cancer, and all sorts of things :D, well supposedly anyway It’s also cheap, put in Vitamin C and raise the cost of the product. One thing to remember though is smoking cigarettes actually does deplete the body of vitamin C quicker than non-smokers, so smokers should take in “a little more” between 10 and 50 mg per day, depending on how much you smoke ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [September 12, 2009, 5:01pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/11 "2009-09-12T17:01:35Z")
[Cecil says this.](http://www.straightdope.com/columns/read/241/will-vitamin-c-cure-the-common-cold) ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [September 12, 2009, 5:08pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/12 "2009-09-12T17:08:36Z")
Ascorbic acid (vitamin C) is also added to many processed foods because it acts as a preservative. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [September 12, 2009, 8:11pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/13 "2009-09-12T20:11:46Z")
> [@foolsguinea](#): > > And it’s water-soluble, so if you ingest a lot of it, it’ll just flush out easily. Might make you a little too acidic for a while. People’s pH generally doesn’t change much. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [September 12, 2009, 8:23pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/14 "2009-09-12T20:23:42Z")
> [@Markxxx](#): > > Vitamin C is a cure all for the common cold, cancer, and all sorts of things :D, well supposedly anyway Anything that starts with _c_, really. Crabs, canker sores, carpal-tunnel syndrome, crotch-rot. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [September 12, 2009, 9:30pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/15 "2009-09-12T21:30:36Z")
> [@Musicat](#): > > [Cecil says this.](http://www.straightdope.com/columns/read/241/will-vitamin-c-cure-the-common-cold) That article is old and outdated. Recent studies have shown that vitamin C (ascorbic acid) does shorten the duration of a cold and alleviates the cold’s symptoms to some extent. There was a time, a short while ago, that the _Wellness Health Letter_ recommended that the daily requirement of vitamin C be raised to 250 mg, and that this was going to be done. However, that health letter changed its mind due to some new studies. Anecdotal evidence: I have found that it does lessen my symptoms and has helped me on several occasions. But you have to take megadoses. Linus Pauling recommended taking a couple of grams every couple of hours (IIRC) once you have a cold. When I get a cold, I take enough to stifle my symptoms. When the symptoms recur, I take another gram or two, until I get diarrhea. Then I stop. The only side effect from too much vitamin C is diarrhea. I don’t know why sports drinks would add vitamin C, except as a selling point. Some sports drinks add the B vitamins, since those are necessary to use the fuel for energy. As to vitamin D, it comes in several forms. Your body cannot make toxic amounts of vitamin D no matter how much sun you get because the form your body makes is safe in megadoses. This is what I recall, but I’d have to do some searching to verify, which I may do later. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [September 12, 2009, 9:59pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/16 "2009-09-12T21:59:38Z")
It seems, after all, that vitamin C is necessary for energy: [Vitamin C | Linus Pauling Institute | Oregon State University](http://lpi.oregonstate.edu/infocenter/vitamins/vitaminC/) > [@](#): > > In addition, vitamin C is required for the synthesis of carnitine, a small molecule that is essential for the transport of fat to cellular organelles called mitochondria, for conversion to energy ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [September 12, 2009, 10:59pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/17 "2009-09-12T22:59:54Z")
> [@](#): > > But it’s highly questionable if doses at multiples of the RDA have any benefits beyond what one gets from the RDA. Well, no. By definition, 90% of people need less than RDA, and 10% of people need more than RDA. Sometimes considerably more. However, RDA is often just a guess (in which case we don’t know if RDA is really sufficient for 90%). I wish we spent even a fraction of what we do on drug research (and bullshit ‘nutrition’ research of what does and does not give us cancer) on knowing more about vitamins. ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [September 12, 2009, 11:03pm UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/18 "2009-09-12T23:03:56Z")
> [@](#): > > There was a time, a short while ago, that the Wellness Health Letter recommended that the daily requirement of vitamin C be raised to 250 mg, and that this was going to be done. However, that health letter changed its mind due to some new studies. Are you sure it wasn’t due to a thundering herd of cynics still hung up on the old debate? ---
**Author:** ![qazwart](https://avatars.discourse-cdn.com/v4/letter/q/5fc32e/32.png) [@qazwart](https://boards.straightdope.com/u/qazwart)\ **Post date:** [September 13, 2009, 1:55am UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/19 "2009-09-13T01:55:22Z")
Vitamin C is a necessary nutrient, but the mega doses specified by some people have never been shown to be of any benefit. The big thing about Vitamin C is that it is cheap, water soluble, and won’t kill you if you over dose on it. Thus, you can pack a drink with Vitamin C, advertise the _benefits_, and watch the dough roll in. When I was a kid, there was some sugary punch drink called "Hi-C’ which was advertised as being good for you because it contained 100% of your daily needs of Vitamin C, or that it had more Vitamin C than orange juice. Quick Google reveals it is still around, but now sold as a energy drink. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [September 13, 2009, 2:41am UTC](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817/20 "2009-09-13T02:41:44Z")
> [@barbitu8](#): > > That article is old and outdated. Recent studies have shown that vitamin C (ascorbic acid) does shorten the duration of a cold and alleviates the cold’s symptoms to some extent. If so, Cecil needs to be notified _immediately_ so that report can be brought up to date. Got some cites to help him? > [@](#): > > Anecdotal evidence: I have found that it does lessen my symptoms and has helped me on several occasions. But you have to take megadoses. Linus Pauling recommended taking a couple of grams every couple of hours (IIRC) once you have a cold. Also anecdotal: Thomas Glovich says Pauling was once asked if he and his wife ever caught colds. He said, “It’s true. We don’t get colds at all. Just sniffles.” [Next page](https://boards.straightdope.com/t/whats-up-with-vitamin-c/509817.md?page=2)