18 replies to this topic

[stocks]

The human body can generate 10,000 to 12,000 international units (IU) of vitamin D from a half-hour of summer-sun exposure.

http://www.sciencene...041009/bob8.asp

[OEXCHAOS]

I'm told that it's not so easy to get 3 minutes of real exposure to the sun at any time. I've got long sleeves on often, and I go from home to car pretty quickly. I'm never without a shirt. During the winter, I'd be lucky to get 30 minutes a month. Mark

[OEXCHAOS]

MM, I can tell you lots of stories about alcohol poisoning and even death. That hasn't caused me to change my regular consumption of red wine.

I say this with respect, but waving folks off a suppliment just because excessive does MIGHT be toxic is conservertive to the point of damaging. At least that's what I conclude reading this synopsis:

http://www.npr.org/t...storyId=5503161

So we have these potential benefits with plenty of promising research behind them, plus some evidence of health risk from inadequate vitamin D, evidence of 400% of what I just suggested taking being harmless, as well as a high probability of at least my wife and I NOT getting enough sun during the winter months and thus having a shortage of D in our systems.

It strikes me that my risk at 1000 IU a day during periods when I'm not getting any sun is nil, while my risk of some illness or another from a lack of D is at least measurable.

And then I have the unreliable anecdotal evidence that I've not gotten sick since I started taking D on that regimen (take it when I'm not in the sun, don't when I am).

I'm always concerned with medical practitioners freak out when the see an OD case on anything. People do stupid things. They also lie about it afterwards. A few cases of D poisoning, when 100's of thousands of folks have been increasing their consumption shouldn't be surprising. It has nothing to do with the safety of D and a lot to do with the fact that some folks consume anything good to the point of it being bad. I hate policy being catered to the dumbest common denominator.

Best,
Mark

[maineman]

Here's the "doctor's" dilemma. Can a doctor, in good faith, reccomend something that is not proven? Our motto is "first do no harm". If you take some time to read through the good literature, say, the New England Journal of Medicine for instance, and its editorials, you will see how we grapple with these ethical questions. We WANT to do the right thing, but as scientists, we want to be pretty dang sure that we know what that right thing is. You are perfectly correct in your assumptions: "How bad can a 1000 units of Vitamin D be?". And, you are "probably" safe. And it "might' help prevent some illness and it "probably" won't cause you to suffer from Hypervitaminosis D. Just do your best to educate yourself on the risks and rewards of ANYTHING you consume, or any therapy you opt for. Anyway, don't get me wrong. I didn't mean to imply that anyone who took extra Vitamin D was at risk for toxicity, I only tried to point out that there is no free lunch, and Vitamin D is potentially toxic and not exactly the "low risk" option. The good news, as I've pointed out here before, is that I have great faith in our scientific process and proof is proof. When science proves one way or another on Vitamin D it will become standard of care. This is how science has always worked. THEN one can still choose to ignore the findings or not, but at least the evidence will be available. Until then, caution is a good thing. mm

[stocks]

Here's the "doctor's" dilemma. Can a doctor, in good faith, reccomend something that is not proven?

mm

Rather than recommend you could just explain the pro's and con's.
BTW I have taken 800 IU of vitamin D daily for 25 years.

[OEXCHAOS]

Actually, MM, you can put that conservative nature to good use and tell us what levels of D consumption start putting us at risk of OD? Are the some contexts that are more dangerous than others? With my openness to fluid risk-reward relationships, comes a need to know where the line is so I stay well away from it. Mark

[maineman]

Actually, MM, you can put that conservative nature to good use and tell us what levels of D consumption start putting us at risk of OD? Are the some contexts that are more dangerous than others?

With my openness to fluid risk-reward relationships, comes a need to know where the line is so I stay well away from it.

Mark

Well, my name should be motor mouth, not maineman, as I am NOT known for my short replies, but here goes.

THere are 2 MAJOR aspects to Vitamin knowledge. The first was the discovery YEARS ago that certain nutrients, which came to be known as the vitamins, were needed to prevent (or cure) a variety of diseases. These include rickets, beri beri, sub-acute combined systems disease, scurvy and many others. As science got better we were able to isolate these substances and measure them and, like any other drug therapy, evolve an amount that was considered appropriate for the treatment or prevention of these unfortunate illnesses. These are now known as the RDA or reccomended daily allowances. These diseases are SO unfortunate that an international effort led to supplementation in basic foods and we've done a terrific job helping millions.

The SECOND part of the Vitamin story is the home-grown "intuitive" or "I can figure this out on my own" story, which has led to Vitamin stories, theories, testimonials and all-out kookiness that has so infiltrated society that Vitamin sales now exceed medical prescription sales by billions of dollars and is one of the most lucrative industries around. The vitamin industry was and is the King of the Scam. That said, there has been only ONE scientific study to date that has shown any benefit to taking MORE than the RDA.

In other words, we know well what you need to prevent and cure some serious illness and we know that by years of hard work and excellent science. That same hard work and excellent science has NOT shown any benefit by taking MORE vitamins. (not because of some "agenda", but those were the results of the science) It's all out there in black and white.

Except FOLIC ACID in pregnant women. This clearly reduces the risk of neural tube defects and is well documented.

So, to answer your question. EVERYONE'S diet and lifestyle is different, as is our skin tone, ability to absorb light, synthesize vitamin D, etc. Having said that, it appears that vitamin D "may" be safe up to 2000 units a day. Caveat emptor. Current RDA is 200 kids 400 adults. I've already shared with you this summer's studies on higher doses and the increased incidence of kidney stones and ectopic calcification of tissue.


mm

[EntropyModel]

...high probability of at least my wife and I NOT getting enough sun during the winter months and thus having a shortage of D in our systems.
...
And then I have the unreliable anecdotal evidence that I've not gotten sick since I started taking D on that regimen (take it when I'm not in the sun, don't when I am).

Best,
Mark

An alternative to remove toxicity risk is too get a UV lamp during the winter, as interestingly you cannot get toxic effects from sunlight production of Vitamin D.

As for fat buildup of vitamin toxicity, I'd thought i'd pass along a technique well know to athlete's with regard to reducing toxicity of any suppliment which is called 'cycling', where an athlete will 'period on, period off' a suppliment - you NEVER take it everyday. That allows your body time to remove any toxic effects that may exist( you hope, large amount guesswork).

For example, you could suppliment 1000units 5 days a week, 2 days off...5 on..2 off etc Of course its very much trial and error.

But since you've already conducted an experiment on yourself by taking it at 1000units daily, and as you say have not suffered toxicity, probability is high your risk of toxicity is low at your current suppliment level, and 'cycling it' is unnecessary, but it would reduce your risk further.


FYI - Personally I do not take any vitamin suppliments, for a few reasons. This is a huge topic in its own right of 'how to make health decsions'. I don't claim I can prove what i'm doing it 'right', or anyone else should do the same because the science of nutrition if very weak unfortunately due to inherant complexities of studies in human beings. That leaves us all in a difficult position of 'guesstimating', but you gotta' make choices. I make mine in order of priority based on -

a. weighing up what limited science there is. I understand mainman's position as a Doctor of restricting himself in advice to peer reviewed science to forefill 'first do no harm'. The harm in his case means 'direct harm'.

Like yourself though, I agree there is also indirect harm by 'missing out' on something that might do us good, so we are left the difficult task to assess the 'less certain science'. This is only possible if you have a thorough understanding of science of the body, because most 'scientific claims' are flawed, usually inversely proportional to the marketing campaigns behind the ( though to be truthful, even the peer reviewed science ain't that certain either due to methodlogical problems, statistical problems and peer review problems.)

b. personal experience - if (a) is inconclusive, I try it and see, of course that's only possible for short term effects, not long term. Such a limited personal 'study' is fatally flawed and not science, but hey if its appear to work for a person...I'm not going to argue it.

I take little notice of anecdotal stories...I hear them all day and night ( due to being surround by fitness freaks like myself) .... about this and that wonder substance...but my own person experience tells me this is wishful thinking, like trading there are no 'silver bullets' in heath. I don't trust most 'science' either, because I know alot about science, and most of it is terrible.


So with all that said, here why I don't take suppliments:

1. As maineman has stated well, vitamins ( and most anything you consume) are biologically active. The cause-effect relationship LONG TERM is currently beyond our science to assess, so its a gamble what its doing to you over a a lifetime. My current assessment is its likely damaging.

2. Even on the short term, the science is very unclear whether the body utilizes vitamin suppliments the same way as foods, because foods contain complex cocktails of biologically active nutrients, which studies suggest act in synergy, and isolating them removes that, and may infact be damaging.

3. I can obtain close to RDA from my diet, and claims that food don't contain the nutrients they're supposed to, ignore the fact the body has a far higher absorbtion rate from food.

4. Vitamin's are just a small subset of the bio-available nutrients. Unless a person intends popping hundreds of pills to obtain them(which may not work anyway) its far easier to obtain a 'full spectrum' of nutrients from food. Put it another way, I suppliment with 'food', consuming as many different foods as possible to maximize my nutrient profile.


Mark

Edited by entropy, 22 December 2006 - 02:28 PM.

[stocks]

Actually, MM, you can put that conservative nature to good use and tell us what levels of D consumption start putting us at risk of OD? Are the some contexts that are more dangerous than others?

With my openness to fluid risk-reward relationships, comes a need to know where the line is so I stay well away from it.

Mark

In terms of the likelihood of poisoning, Vitamin D seems to be one of the least poisonous substances known. Overdose occurs at more than 100 times the daily RDA (more or less a bottle of vitamin D tablets per day), for several months. Acute one-time overdose requires over 50mg (ten thousand times the RDA). Foods contain low levels, and have not been known to cause overdose. Overdose has occurred due to industrial accidents, for example when incorrectly formulated pills were sold or missing industrial concentrate cans misused as cans of milk.


Comparative safety statistics

Deaths by vitamin poisoning appear to be quite rare in the US, typically none in a given year. However before 1998, several deaths per year were typically associated with pharmaceutical iron-containing supplements, especially brightly-colored, sugar-coated, high-potency iron supplements, and most deaths were children[1]. Unit packaging restrictions on supplements with more than 30 mg iron have since reduced deaths to 0 or 1 per year[2]. These statistics compare with 59 deaths due to aspirin poisoning in 2003, 147 deaths associated with acetaminophen-containing products in 2003, and an average of 54 deaths per year due to lightning for 1990-2003.


http://www.answers.c...ervitaminosis-d