Dev29 wrote:I am a bit of lurker here but my main question w/ vitamin d is whether or not it impact men and women equally. I don't have any paper reference handy, but that it doesn't "work" in men or at least not as well.
Does anyone here have any information?
I think the optimum amount to supplement with is different from person to person.
But here is a good graphic showing the relationship between supplementation with Vitamin D3 and your blood serum level:
You can see that blood serum level of 25OHD that is considered "toxic" by many doctors is 250 nmol/L. According to this data, taking 10,000 IU's of vitamin D3/day would raise your blood serum levels to around 200 nmol/L.
However, in a recent high dosage study involving people with MS and vitamin D, the treatment group received an average of 14,000 IU's over a 52 week period with a maximum dosage of 40,000 IU's (I posted this information previously, but I'll post it here again for conveinance):
And here is a graphic from this paper:
So you can see from the chart in the lower right that the highest levels of 25OHD blood serum for the treatment group ranged from about 250-550 nmol/L for the same dosage of 40,000 IU's.
Personally, I take 40,000 IU's/day and have a 25OHD blood level of 250 nmol/L. I am not recommending that anyone take this amount, but this is what I have to take to reach the lower end of the "toxic" range. Please note: Toxic in conventional medicine means that you become hypercalcemic which means you have too much calcium in your blood. However, the people in the trial had normal calcium levels even though they were supplementing with 1200mg/day. To me, this means that high doses of vitamin D does not cause hypercalcemia, and in my case my blood calcium levels are on the low end of the normal range (9 mg/dL) without supplementation.
So, it is not just a matter of taking a certain amount of vitamin D/day. You have to monitor your blood serum levels. From my own personal point of view I have decided to not believe in conventional medicine and increase my blood serum level to the upper end of normal because there is a lot of evidence that vitamin D prevents auto-immunity by promoting regulatory T-cell development. Since I have been on this dosage, I feel better than I have ever since I became sick and have not had any relapses like I used to. But my situation is anecdotal. We really need to find out what are the optimum blood levels to prevent autoimmunity. Unfortunately this is just starting to happen now and I fear it may take a decade or two before this testing is completed.
Here are the conclusions from the high dose vitamin D study I posted above: