Posted by JLx on November 2, 2004, at 11:20:57
In reply to Re: Vitamin D and depression » JLx, posted by tealady on November 2, 2004, at 3:32:11
> 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.
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."
Of the 4000 IU dose, they said,
"Conclusions: The 100-µg/d dosage of vitamin D3 effectively increased 25(OH)D to high-normal concentrations in practically all adults and serum 25(OH)D remained within the physiologic range; therefore, we consider 100 µg vitamin D3/d to be a safe intake." http://www.ajcn.org/cgi/content/abstract/73/2/288?ijkey=0d2c692a66588c15ca6392da9466e0e5a83add24&keytype2=tf_ipsecsha
Some of the most intereting links are those Dr. Vlieth makes to his critics.
"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
So, he's saying that it takes 40,000 IU of long term consumption of Vit D to cause hypercalcemia.
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
"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)."
That's 10,000 IU.
The later he says,
"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."
Now this is an interesting commentary by Dr. Vlieth, where he discusses and explains the difference between the "required daily allowance" and "adequate intake".
"To qualify as an RDA, a dietary recommendation must meet the known needs for the nutrient of practically all healthy people.15 This is an objective criterion which requires evidence that almost all adults taking the RDA achieve a tangible health benefit or, alternatively, a target blood level that would imply a health benefit. Thus, in contrast to the situation for an RDA, we are not safe in assuming that taking the AI for vitamin D will do anything at all."
"Long-term use of the official toxic dose, the "lowest observed adverse effect level," 100 µg (4000 IU) of vitamin D3 per day, is in reality a physiologic dose that has no effect on calcium levels in serum or urine.20 ... The physiologic, sun-derived product is vitamin D3 (cholecalciferol). ... All iatrogenic cases of vitamin D toxicity in the literature seen by us have involved vitamin D2, a product not normally present in humans.16 Yes, poisonings have occurred with the physiologic molecule, vitamin D3, but all of those cases involved intake on an "industrial scale," with unintended, prolonged daily consumption far beyond 1000 µg (>> 40 000 IU).21
Until vitamin D is consumed by all adults in amounts much greater than is the case today, in accord with an RDA that has not yet been established, many adults at northern latitudes will continue to exhibit undesirably low concentrations of 25(OH)D.6,7,8,9,10,11 In the interim, we believe that a daily supplement of 25 µg (1000 IU) of vitamin D3 is advisable for all adults." http://www.cmaj.ca/cgi/content/full/166/12/1541
> 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>
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. So, there is no way in effect to overdose no matter how long in the sun. 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 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.From your article:
>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.
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>In the absence of sunlight, a daily intake of 5 to 10 microgram (200 to 400 IU) of cholecalciferol is considered adequate.
That is the point of contention with the current research, which I am finding compelling and convincing.
> 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.
This has been the conventional wisdom, but where's the proof?
> 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.Not sure why you're telling me this. I don't take lithium, or gingko either at the moment.
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! ;)
JL
poster:JLx
thread:410247
URL: http://www.dr-bob.org/babble/alter/20041022/msgs/410583.html