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Nutrition: Vitamins on trial (nature.com)
64 points by sizzle on July 3, 2014 | hide | past | web | favorite | 51 comments

Aside: I found the following visualisation fun and somewhat interesting (on supplements and the ailments they might be good for). It's changed a lot over the years and it links off to the underlying spreadsheet.


This is a nice graph (but does the X axis have a meaning?)

But the important thing there is that they're measuring their role as a supplement, however, most of them are needed (and present in a healthy diet), while some aren't

Potassium is a needed element of a diet, and as the article mentioned, there seems to be a lot of deficiency, but maybe a better understanding of deficiency/needed dose is needed.

Scroll down the page and you'll see a description.

"This image is a “balloon race”. The higher a bubble, the greater the evidence for its effectiveness. But the supplements are only effective for the conditions listed inside the bubble.

You might also see multiple bubbles for certain supps. These is because some supps affect a range of conditions, but the evidence quality varies from condition to condition. For example, there’s strong evidence that Green Tea is good for cholesterol levels. But evidence for its anti-cancer effects is conflicting. In these cases, we give a supp another bubble."

edit: Apologies, I misread your comment. The X-axis can be modified on the interactive version to sort by: alphabetically, popularity or scientific interest. The static version is alphabetical. Beyond that, it's just to help spread things out to be readable.

I'm asking about the position of the bubble on the X axis (maybe it doesn't mean anything), I know about size and Y axis position.

It does not appear to me that the X axis has significance; perhaps the arbitrary spacing (especially at the top) is just for readabilitys' sake.

Alphabetic order.

Yeah, looks like it

This article is a good example of the arrogance around nutrition. A third possibility is that we don't know enough to be able to manufacture vitamins in a factory.

When one eats un-manufactured food

* for a given nutrient there are many different forms of it

* there are many inter-related nutrients that effect each other (nutrient synergy)

Take a look at how many forms of Vitamin A there are on the Wikipedia entry. The idea that we can pick one and load up on it may not be correct. This is true of many minerals also because they need to be bound with something else (magnesium malate, etc).

The odd thing about nutrient synergy is that it is very well established scientific phenomenon. But it just doesn't fit well with our reductionist approach to science.

I work for the FMCG (Fast moving consumer goods) and can tell you vitamins do one thing very well: help sell stuff. (Vitamin c is easily added to just about anything to make it 'more healthy' looking. I think vitamin c is probably the most abused added vitamine...

> Vitamin c is easily added to just about anything to make it 'more healthy' looking.

No, it's for increasing shelf-life and maintaing the flavor/aspect. Vitamin C is an antioxidant.

There's a bunch of Cosmetic companies using Vitamin E in their products too. With slightly more evidence that it does something... if I remember correctly.

Not counting what vitamin E may do to skin (it supposedly helps it), it keeps other oils from going rancid. So, it's a kind of a preservation measure.

Also the LD50 of vitamin c is so high that it's practically not possible to die from over-consumption of it. Not that anyone really would try, but I find it amusing for some reason.

Isn't vitamin C a pretty good preservative agent for food?

It's an antioxidant. You sometimes see it on labels as ascorbic acid (if the product isn't touting its health credentials).

Our current causal models of how nutrients behave in our bodies are woefully incomplete. Many of the substances referred to under the term "Vitamin X" come in many forms that do different things. It is unsurprising that an isolated compound doesn't help much. MealSquares address exactly this issue. We know we're supposed to eat a variety of whole foods but we don't. So we put a whole bunch of nutrient dense foods in a convenient package. Bioavailability is much much better than supplements.

There's also the fact that the absorbtion of a nutrient can depend on what other nutrients are being digested at the same time. For example, adding iron to breakfast cereals is completely ridiculous.

First of all, it's added as pure iron. You don't absorb iron in its mineral form, it needs to be in some organic form to be digested. So that already makes it totally pointless.

But let's ignore that for a moment and pretend we could digest mineral iron. Turns out that if your food contains iron and calcium, the calcium will take precedence and effectively block the absorption of iron. And what do we pour on our breakfast cereals? Oh, right. Milk.

It also can work the other way around: vitamin C helps with the absorption of iron.

It shouldn't matter whether something is a drug, vitamin, or dietary supplement. What matters is whether there is scientific proof of efficacy for what you are trying to accomplish.

I have long struggled with social anxiety, and under stressful situations severe panic attacks. I found out via examine.com (fantastic website for getting scientific info on supplements) that inositol (vitamin b8) is potentially more potent than SSRIs in treating anxiety disorders. I bought a tub of the stuff and sure enough there has been a dramatic dose-dependent reduction in symptoms.

Unfortunately, because it's "just a vitamin" there is limited data available, so I have no idea how safe it is or whether it has any long-term effects.

I wish there were small supplements that contained maybe 10-20% of the recommended amounts of things. I eat reasonably well. Most of the time. So I probably get enough of most of the vitamins and minerals. But I'm sure some I get more than others so a small boost might help overall.

But I don't want to take one of the multivitimins that has 100% of everything in, that just ensures that I have way too much of some things.

> "... that just ensures that I have way too much of some things."

That only matters if the body cannot quickly flush or discard the things it doesn't need. It's probably different for each type of supplement. As a supporting example, it would be quite difficult to drink too much water as there's an easy mechanism to deal with it [1].

[1] Before anyone leaps on that statement, yes, I'm aware that it is possible to overdose on water. http://en.wikipedia.org/wiki/Water_intoxication

Vitamin A and D are more problematic because they are fat-soluble and the excess can’t be flushed away in pee. Other vitamins, like vitamin C, are water-soluble so a little excess is not so bad, but IANAMD. http://www.medicinenet.com/script/main/art.asp?articlekey=10...

In fact, last time I looked into multivitamins, most have "megadoses" of nutrients - doses far in excess of the DRV. Either because it's easier for the manufacturer to produce that way, or because 1000% of something sounds better to a layperson than 100%. The major advertised brands like Centrum are especially guilty of this and the generics copy to look equivalent.

To even get a multivitamin with only 80-100% of DRV max, you have to look for a "mature" multivitamin, usually labeled as age 50+ - 60+.

I don't have a varied or complete diet, so I take a mature multivitamin - Kirkland (Costco house brand) Mature Multi, well reviewed in Consumer Reports and elsewhere when I looked into vitamins. And really cheap, as low as $10 for a 400 count bottle.

If you're really interested in less than 100%, most ought to be easy to split in half with a pill splitter.

Split pills in half. Or just take them every couple days, instead of everyday.

My thinking on vitamins is governed by several principles:

The data is inconclusive

As a recreational and occasionally-competitive athlete in powerlifting, my vitamin requirements are likely abnormal, especially during intensive training

Medical studies usually focus on mortality, whereas I'm also interested in athletic potential and quality of life

I take a multivitamin and sometimes macro-dose on C and E.

All drugs are prescribed to cure diseases. Feeling or performing "better than well" is not considered an acceptable reason to take any vitamin, supplement or drug according to traditional medicine.

And no D?

I take D in the wintertime.

I'm not sure I completely understand the criticism of the negative results. All of the supposed biases seem to apply equally to the control group (more healthy to start with, different baseline intake, not completing the course of pills) and to other studies in different areas.

The supplements industry is basically snake-oil so far as I can tell. Unless you have a known deficiency, or a horrifically unbalanced diet, as far as anyone can tell they're a waste of time and money.

"... so far as I can tell."

Look - anyone of us can just spout our opinion. What separates HN is that people take the time to explain their reasons and often credentials. If you said, "Here's why and BTW I've worked in this industry as an XYZ for 25 years" - your opinion might matter. But as stated you've just stated your own personal opinion as though it is fact. Downvoted for that reason.

>> What separates HN is that people take the time to explain their reasons and often credentials.

You must be thinking of HN from a few years back, it's basically just a discussion site these days AFAICT.

My opinion wasn't on the supplements by the way, it's on the industry. The industry which in Europe has to include disclaimers in all its advertising to the effect of "this stuff might be useful for the elderly and those on restricted diets" because there's no evidence for anything. The industry which heavily resists any effort to regulate it various medical claims in the same way actual medicines are regulated. It's shady as hell.

I assumed this was common knowledge.

>>or a horrifically unbalanced diet

Heh, have you seen the average US citizen's diet? I think a significant percentage of diets among USA inhabitants can be called "horrific" without being an exaggeration.

We have stuff like this happening... http://www.heartattackgrill.com/heart-attack-grill.html

"Over 350lbs? Eat for Free!!!" ---Seriously, that's a policy of this business.

So, I mean, the food on there is probably not the healthiest (the unhealthiest thing about it are probably the portion sizes, though, not anything it contains) and it might be a bit unbalanced from a macronutrient point of view (though I’m not even sure about that, maybe it’s a bit low on proteins and a bit high on fats, also, including the sodas it’s certainly high on sugar and very probably also high on salt) but I’m not sure you would end up with any deficiencies by eating that stuff. Meat, cheese, vegetables, bread. It’s all in there. The vegetable part is a bit small, but that’s about it.

In terms of variety burgers really aren’t that bad. It would be much more concerned about getting too much of something, not too little.

Diet issues are one of those things that are really easy to miss. You can easily get used to feeling a little worse every day until significant issues sneak up on you. With that in mind a basic multivitamin is a cheap option.

You don't need to taken them every day, one multi vitamin ever other day or even one day a week can actually help with a lot of issues over the long term. Much like exercise consistency is more important than a few years of excess.

PS: I have actually been referred to a nutritionist due to medical issues.

So basically... vitamin D and probably not much else.

If you have a known deficiency, sure, but a quick web search will show you that it's arguable what level is deficient, and that it's arguable that supplementation has a good effect on anyone that's not suffering from a few specific conditions.

So I'll repeat - unless you have a known deficiency or a restricted diet, they're a waste of time and money, and the industry is snake-oil.

While I agree, at least for Vit. D, the issue is what is considered 'deficiency' is quite low by doctors/blood tests. I don't remember the values, but even doctors that a few years ago laughed (yes, laughed) on my wife and mine face because we we concerned about it and the effects of low Vit. D in her pregnancy are now recommending to their patients some supplementation even for known normal levels. (One doctor told us the only concern for low Vit. D levels were for the +65 year olds for example)

But real clinical evidence is still pretty shaky at best. Like 5 years ago there was a lot of hype about Vitamin D and a lot of hope that new studies would conclusively show value in supplementation, but it didn't turn out that way, e.g. http://www.medscape.com/viewarticle/819670

It is also dependent on your profession and location. If you are a collegiate or professional athlete living in the Northern US where sunlight exposure is generally bad for 6 months out of the year, then while your Vit D levels may just be below-average (but nothing major for a normal human), this could be a real issue regarding athletic performance.

Supplementation and testing must always be taken in context. The average sedentary human does not have the same caloric needs as the aspiring professional athlete, nor do they have similar supplementation needs either.

I fully agree. Athletes, pregnancy, high-stress jobs, depression, etc. Each have different concerns and specific nutrition focusing on them can be quite efficient at mitigating symptoms/improving results. Also location as you mentioned and genetics as well can influence the requirements of certain nutrients.


I don't remember the exact numbers, but if the sun is out there, around 10min (or maybe up to 30min) under the sun with light clothing will give you the needed Vitamin D dosage.

Now, in high latitude winter, the time needed is in the order of hours. With heavier clothing this becomes much harder.

My parents are general practicioners, and for the last few years they have basically been told that the rule of thumb is to assume everyone is vitamin D deficient until proven otherwise (where "works outside in the sun all day" is an example of proven otherwise).

That doesn't mean that they have evidence that supplementation would actually help people. The currently available data says it could help, could do nothing, and could harm: http://www.medscape.com/viewarticle/819670

I have regularly read that all it takes is 15-30 minutes of direct sun exposure per day to generate the RDA of vitamin D. Is that inaccurate (as someone who slathers his kids with sunscreen I would really like to know)?

Here's a nifty calculator that tells you vitamin D values for exposure times taking season and latitude into account.


I don't know the answer to that. However, assuming you are correct, I live in a country where direct sun exposure is a rare commodity even in summer, so the recommendation to my parents could still make sense then.

magnesium is also often deficient

And iron.

years ago, probably also in nature, I read that the only certain thing that the studies found about vitamins was that it made for expensive urine.

It's even worse: For decennia it was thought too much vitamin C would exit your body easily by urinating. Instead it's rather harmful: http://www.nytimes.com/1998/04/09/us/taking-too-much-vitamin...

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