Posted by JLx on November 2, 2004, at 12:07:55
In reply to Vitamin D and depression, posted by JLx on November 1, 2004, at 17:27:18
Hi Larry,
From the "Supplements for brain fog" board,
>I'll just make a summary statement here, but the 4000 IU recommendation is based on solid research, and it's quite a new finding. It takes a while for the facts to filter through into what we know.
Yes, and often alternative med is on the cutting edge. I remember well how many years earlier I was reading about free radicals and antioxidants there before it hit the mainstream. And look at the medical establishment's refusal to pay attention to the guys who made the ulcers/H. pylori connection. My impression is that this might be one of those things, and if so, it could take years before we all "know different" and meantime we're setting our health back that much more too.
> I think the oral toxicity of vitamin D is related to the bolus effect. What that is is the huge serum concentration spike that comes from uptake across the gut wall. Vitamin D synthesized in skin trickles out into the blood, via diffusion. The total amount made from acute sun exposure is not just suddenly dumped into the blood. It's the essence of a timed-release vitamin D repository.Ok, I'm not understanding this I don't think. I read that it only takes 15-30 minutes of sunlight to get 20,000 IU of Vit D (if Caucasian). You're saying that amount is in the skin and then trickles out slowly into the blood? Then once it's in the blood, the excess accumulates in the fatty tissue. When needed and not being supplied through the skin or diet, the body then draws it out of the fat. I still don't see the difference between the Vit D that's stored in the fat that originally derived from the sun or that which originates in the diet per food or supplement. What if you were in the habit, as some people surely are or were historically, of eating a lot of salmon daily while also getting a lot of sun? No danger, surely! So, is there some difference simply in the supplemental form and what it does and how it's utilized later? That seems to me to be the crux of the problem and I haven't read anything to suggest that taking cholecalciferol is somehow different in the body other than as you say, a short spike as it's dumped rather precipitiously into the blood stream. But again, surely that is not so different than eating that salmon while basking in the sun.
And once it's in the fat, and NOT needed/drawn by the body as it must be for those who get a lot of sun day after day, then what?
This is interesting about obesity and Vit. D:
http://www.cholecalciferol-council.com/obesity.htm
"10. Obese subjects obtain lower 25(OH)D levels when exposed to ultraviolet light or when they take supplemental vitamin D.
A. True.
B. False.True. Obese subjects appear to deposit some their vitamin D in their excessive fatty tissue, thus impairing their ability to raise their 25(OH)D levels."
So the more fat you have, the more of the Vit D that you do get, is deposited in the fat. I would think all that fat stored Vit D would be a kind of insurance against becoming deficient. But it sounds like it's the opposite from that and the other correlations he notes.
That compounds my confusion about this storage business and how it becomes toxic. A saturation point is reached? So then too much is in the blood all the time?
And perhaps this is the stupidest of questions, but what happens to the Vit D stored in fat when a person loses weight? Is it broken down instead of released when the fat stores themselves are used for energy?
It sounds as if small doses of Vit D throughout the day would be the answer to the bolus problem. When physicians do supplement to bring up Vit D levels, they do so in pretty large doses of 10,000 IU. What do you think of that sublingual emulsified version? An advantage or problem in bypassing the stomach?
> Did you catch note of the positive effects arising from a single oral dose of 100,000 IU? I recall seeing that last night, as I was skimming. It gives one pause, with respect to oral toxicity.
>
> LarYes, I notice also that the massive by-accident doses, sometimes huge and over a fairly long period of time, were apparently not irreversible.
It's all very confusing. It sounds as if we've been scared a lot and thoroughly for no good reason.
JL
poster:JLx
thread:410247
URL: http://www.dr-bob.org/babble/alter/20041022/msgs/410598.html