I have two questions. First one is about vitamin D. So I've read about vitamin D quite a lot.
I know that in general, people who get a lot of sunshine lifeguards have levels between 40 and 60
mg. I know that you recommend something like that as well, 40-ish, 50-ish. My question is
anecdotally, I've seen a lot of people feel better with somewhat higher levels
closer to 80. So for someone who doesn't have any parathyroid issues or any other issues
related to vitamin D who's taking magnesium and K2 to help with vitamin D absorption,
would you see any dangers in trying to attain and keep a level kind of closer to 70 or 80?
Yeah. My baseline default is everyone should be 30 to 40 nanograms per milliliter.
I do think that there's considerable reason to think that people who are not of White European
ancestry can get away with lower levels, but I don't think there's any harm really going above
30 nanograms per milliliter in general. And so I think it's just a good default to say,
"Stay out of the lower than 30 nanograms per milliliter range." That's my baseline.
In terms of higher levels. So in the lifeguards, the data that was popularized,
especially by Reinhold Vieth about the Israeli lifeguards who had levels in the 50s that was used
15-20 years ago, was popularized as proxies for our ancestral levels, thinking that they were
more representative of the sunshine that we've had in our evolutionary environment.
Which I disagree with and I've written about why. But in that study, a couple of studies there,
they had like 20 times the risk of kidney stones. And so there was a little bit of controversy over
that because people were saying, well, they were also dehydrated and this and that. And of
course they probably weren't supplementing with vitamin A, they probably weren't supplementing
with vitamin K2 or magnesium. But we know from animal experiments that the most sensitive
problem with vitamin D toxicity is that you can get kidney stones before you ever get
hypercalcemia. And that's not surprising, because those lifeguards have hypercalciuria. So their
blood levels of calcium were being maintained at normal levels by increasing the amount of calcium
in their urine. And if the calcium is increased in the urine, then it's going to cause all the same
problems in the kidneys that it would cause in the other organs if you had systemic hypercalcemia.
And so in terms of why some people anecdotally feel so much better at 80,
my suspicion is that there are some people who have genetic differences in their
sensitivity to the vitamin D and that they may be benefiting from higher levels because of that.
But I feel like that's very speculative at this point. And yes, I know that there's some
single-nucleotide polymorphisms that have been identified in the vitamin D receptor.
But in terms of what they do and why they're associated with disease
risk in some cases is really wishy-washy. So I'm not really ready to say anything definitive about
the people who feel good at levels that high. What I would say, is at 80, you're probably
not at a risk for hypercalcemia, but you might be at a risk for hypercalciuria.
And so I would look for that. I think it would be good to just periodically, maybe
more frequently at first. Let's say the idea is to maintain someone on a lifelong
level of 80 nanograms per milliliter. Maybe four times the first year, two times the second year,
once the third year and then every few years thereafter, I would measure the urinary calcium
and make sure that that level is not associated with hypercalciuria in that person. Because if
it is, I think you're putting that person at an increased risk of kidney stones if nothing else.
And then I would say that person wants to get at least 200 micrograms of vitamin K2.
My default would be to say 10,000 IU of vitamin A, just off of the fact that I feel like you're
basically doubling the normal amount of vitamin D in someone who is 80 nanograms per milliliter.
And so, as a base case, you want to double the vitamin A. But I also think that you should
measure the serum vitamin A and make sure that you're not putting that person towards the top
10% of the reference range and pull back if you are. My assumption would be that the vitamin A
turnover is going to be higher in that person. And that a higher dose is not going to result
over the reference range vitamin A. But I would monitor it at the similar frequency as I just
mentioned, just to make sure that's not happening. And then all fat-soluble vitamins do cause
increased turnover of the others, even if they're not being used cooperatively. So vitamin A and D
do some things together. That's part of why they increase their turnover together. But
it's also the case that the machinery for breaking down fat-soluble vitamins is shared
among the fat-soluble vitamins. So if you megadose with one, you will deplete the others. And so
I actually would say this person should probably have like 400 micrograms of K2 and
40 IU of vitamin E per day as a default, just on the basis that you're kind of doubling everything.
There's not really a good marker for vitamin K status. I'm not really happy with them. There's
certainly no marker for too much. For vitamin E, more or less same thing. Plasma vitamin E is a
pretty decent marker of status, but not in terms of monitoring for too much. The only one I would
be worrying about pushing into the toxicity range would be A. And like I said before,
I just keep that at least 10% behind the top of the reference range. That's how I'd approach that.