The widely used daily recommended amounts of Vitamin D (600 IU in the US and Canada) are wrong, by a factor of 10, and based on a math typo that no one caught until 2017: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5541280/. I guess many still don't realize this fact.
"We call public health authorities to consider designating as the RDA ... around 8000 IU for adults"
Vitamin K is needed so that calcium doesn't build up in the vessels but goes to the bones where it's supposed to be. But, taking D and K at the exact same time reduces the absorption of D.
Not at all. Suboptimal, but far better than taking nothing at all.
There are loads of nutrients that technically compete for absorption, but generally it isn’t a concern unless you are taking a huge dose of one. Even then, it’s not like little dog is completely blocked. I’d have to look at the studies the above comment is referencing to determine how much of a concern it actually would be.
Even if taking both together was 30% less effective than taking them apart, in the context that getting people to take a single pill daily with regard to timing is hard enough, it’s still a overall win. That said, I would agree such a situation should be reflected on the label.
“Less effective” is odd here because other commenters are saying that K2 ensures D gets deposited in the right places rather than build up in the arteries (as plaques presumably). So if it is, say 30% less effective, then taking them apart wouldn’t that mean that rather than getting (example) 1,000 IU in the wrong place, you’d get 700 IU deposited in the right place, so it would be more effective rather than less?
The whole idea is that some research suggests that vitamin D may be harmful without vitamin K to offset its effects ("so that calcium doesn't build up in the vessels but goes to the bones where it's supposed to be"). That's all there is to it.
No need to discuss absorption. Furthermore, the idea "taking D and K at the exact same time reduces the absorption of D" is unsubstantiated in medical research
As mentioned, K is more to make sure the calcium absorbed as a result of vitamin D can be properly put away instead of hanging around in the arteries.
Magnesium is very important cofactor for metabolism of Vitamin D (and many other things, it’s a cofactor involved with hundreds of enzymes and such), which people are also generally low on.
I think there may be another big cofactor or two, but they escape my offhand recollection.
absolutely on the Magnesium. Due to our diets being primary processed wheat, sugar, oil, and animals, (and partially due to soil mineral depletion) our diet is persistently low on Magnesium by quite a large margin. the impact of this on the population is not consistent. this really doesn't get enough attention in the media or many other places.
https://vitamindforall.org/letter.html is a letter that goes into why >= 4000 IU daily is recommended based on blood serum levels with more literature review.
"We call public health authorities to consider designating as the RDA ... around 8000 IU for adults"