Posted by tealady on November 4, 2004, at 21:00:32
In reply to Re: Vitamin D, and safety » tealady, posted by JLx on November 2, 2004, at 11:20:57
> > haven't read your posts but my view differs from Lar..
>
> Well, I hope you get a chance to read the links I posted as well as the links on those links, when your exams are over.I promise :)
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> In this one, subjects were given either 1000 or 4000 IU for 2-5 months and as a result the "serum calcium and urinary calcium excretion did not change significantly at either dosage during the study."
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> Of the 4000 IU dose, they said,
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> "Because all available evidence indicates that a long-term vitamin D consumption of 1000 µg/d is needed to cause hypercalcemia, there is a large margin of safety with 100 µg/d. [I welcome any discussion of evidence implicating harm with vitamin D3 (not D2) in adults at doses <1000 µg/d. There is simply nothing published about this, except in infants.]" http://www.ajcn.org/cgi/content/full/74/6/863
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> So, he's saying that it takes 40,000 IU of long term consumption of Vit D to cause hypercalcemia.
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> Here's his discussion of "no observed adverse effect level" and the upper limit established by the Food and Nutrition Board. He makes the point, if I'm reading this correctly, of the same thing I wondered about re children versus adults: FNB).http://www.ajcn.org/cgi/content/full/74/6/866
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> "Unlike the ULs for most other nutrients, the UL for vitamin D is not internally consistent across age groups. According to the model for deriving ULs, adjustments rely on body weight ratios (4). On the basis of what is probably a more rigorously established UL for vitamin D for infants and assuming a body weight ratio of 10, the infant data imply that the adult UL should be 250 µg/d; this value is within the adult physiologic production rate for vitamin D (5)."
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> That's 10,000 IU.maybe due to needing to grow infants and kids need more anyway? they have to form a lot of new bone completely from scratch ?
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> The later he says,
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> "The FNB has not made it clear to health professionals that the LOAEL (not the UL) should be used as the numerator in calculations of the therapeutic index for nutrients. As a result, pharmacists almost always warn patients against taking the highest dose of vitamin D available over the counter (25 µg/pill, 1000 IU). They are warning patients against taking the very dose that adults need to ensure that 25-hydroxyvitamin D concentrations exceed the decision point for vitamin D insufficiency (11). To see first-hand the real-life effect of the current UL for the public, I suggest that readers pose a naive question to their local pharmacist about the risk of taking the 1000-IU vitamin D pills."
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> > Personally if I was you I wouldn't go overboard on VitD(considering your calcium stone history)..and yes, it is probably possibly to overdose from sunlight but most peope tend to burn and move out of the sun after a while<g>
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> Actually, from what I read, the skin system of Vit D intake automatically only allows so much through, and that is the time it takes for a Caucasian to read 1/4 of the way to a sunburn.over here thats maybe a 3 minutes?sometimes..less for babies. Had a kid that would blister in less very quickly..maybe a couple of minutes?...just white skin, nothing wrong.
What strength sun are they measuring?>So, there is no way in effect to overdose no matter how long in the sun.
I know someone who suspects he may have when in Arabia..thinks he went manic from the overdose of sun possibly.
> But what's really interesting is that there doesn't seem either to be any toxicity from the buildup over time, which we're told is the big concern with Vit D supplementation. Which makes sense. As numerous people are now pointing out, our ancestors spent plenty of time in the sun, and yet here we are.
I agree most of us need more time in the sun.
The really poor folk are the women in those muslim countries who are required to cover up fully..they apparently suffer from VitD deficiency..hardly surprising.Most folk who get sunburn don't go and repeat the experience every day:) Actually one likes to stay right out of the sun the next few days...so its inbuilt for sure!..any tiny amount of sunlight stings!
But it IS lovely to sunbake..especially in early spring(or last Month of winter really)..so that tells me that I benefitted from that dose of sun.
If I lived in a cold climate, like say the UK or Canada or parts of the US, I definitely would take some halibut liver oil or cod liver oil daily from November to March say.
Over here its good in winter too, but not in Qld(subtropics and tropics).>
> I think it was on the Mercola site where he makes the point that anybody who lives in a latitude above 30 is at risk for overall Vit D deficiency, simply because we're just not that close to the sun even during our summer months. I checked and see I live at 43.well I agree for the winter months anyway.
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> From your article:
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> >Even in long-term vitamin D deficiency, the plasma calcium level can be maintained by PTH-- at the expense of the bones, which are tapped as a calcium reservoir and gradually are depleted of their mineral content. PTH also reduces the level of circulating phosphate by inhibiting renal phosphate reabsorption. More than 99% of our calcium and phosphate is in the extra-cellular matrix of bone, and the depletion of total body stores of calcium and phosphate in vitamin D deficiency leads to soft, poorly mineralized bones that bend rather than break under stress.
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> That's what I'm worried about. My mother, who is 79, now has osteoporosis. And she had a better head start in terms of diet habits than I have. My 6-year-older sister broke her foot recently by just turning her foot off her shoe. A couple studies that talk about Vit D and parathyroid status: http://www.ajcn.org/cgi/content/full/74/2/206
> http://jcem.endojournals.org/cgi/content/full/86/3/1212
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> >In the absence of sunlight, a daily intake of 5 to 10 microgram (200 to 400 IU) of cholecalciferol is considered adequate.
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> That is the point of contention with the current research, which I am finding compelling and convincing.
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> > Hypervitaminosis D, caused by the overuse of vitamin D supplements, leads to rampant hypercalcemia, hypercalciuria, and metastatic calcification. The toxic state persists for a few months after discontinuation of the offending agent if the overuse of cholecalciferol is the cause, but it lasts for only a week or so if toxicity is caused by calcitriol. Chronic hypercalcemia can result in irreversible cardiovascular and renal damage.
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> This has been the conventional wisdom, but where's the proof?I'm not sure JL of the proof, but I thought maybe this was based on something.
I've heard that taking large doses of both VitD and calcium supps could cause kidney stones..which I thought you had had..so the warning was more to do with that than VitD toxicity in itself. I don't know what level would be needed though.
Maybe you should just get your calcium from diet only if you are going to take large doses of VitD? just in case? Larrian (the urologist whose done kidney ops etc) reckons its dangerous for most women to take calcium supps, and they should try to get the calcium via diet. I only take it as I already had osteopenia and was already on a high calcium diet. I probably should check out all my PTH pathway levels as my phosphate levels are high.I guess one's phosphate level as well as PTH would play a part in the overall picture..not to mention the immune system<g>
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> > my thoughts added
> > and colchicine is in gingko ..so gingko and lithium may tend balance out each other to an extent in their effect on the parathyroids.
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> Not sure why you're telling me this. I don't take lithium, or gingko either at the moment.Oh, I was just trying to do a quick post that I assumed would be maybe read by others as well :) ]
Came across that info when I was looking at the effects of supps to answer a post for TJ I think, but I saw later he isn't on them any more. However many here are so I thought I'd add it anyway, just in case anyone wanted to know.>
> We all know that the medical establishment is notoriously short-sighted and prone to scare tactics concerning nutritional supplements, yet don't think twice about prescribing drugs long term, even for children, that have been tested on limited adult populations for a short time. I'm not much of a conspiracy theorist, but it's a fact that a lot of prevention of disease will put them out of business! ;)LOL..yes I agree
>
> JL
poster:tealady
thread:410247
URL: http://www.dr-bob.org/babble/alter/20041022/msgs/411910.html