It is hard to find advice on K2 doses, isn't it?
I spent ages looking around a year ago, and ended up coming to the following conclusions:
- no need to worry at all about having too much
- 100-300 units seemed like a min-max amount, and matching it to D3 intake made sense. By that, I mean that the more D3, the more K2.
As for your doc’s advice...
With D levels that low, what the heck difference does he think adding a measly extra 600 units a day is going to make? And are you taking D3 or D2(cheaper and significantly less effective).
When I was at your levels i took 6,000-10,000 units D3 a day for 6 months and only just scraped up into the middle of normal.
I started off at a level of 25.
At your levels I have heard of docs prescribing mega doses of 40,000 (or more) units weekly, for several weeks, because sometimes they do that rather than drip feeding daily doses. I think it is cheaper for the NHS to do fewer bigger amounts.
Another thing to remember with Vit D testing, is that the test should not be taken within 48 hours of taking a supplement. This allows the last dose of the supplement to be absorbed out of the bloodstream to where it needs to go, and reveals the true actual levels of D3.
I believe/have read/understand that those of us with capacious fat storage (me!) need significantly more, higher dose, Vit D3 than slim people to address a deficiency. This is because all of us (including fat storage cells) have been deficient because the body strips nutrients from storage (fat) to use in core systems. So whenever we take a supplement, the D3 circulates in the bloodstream and is sucked out of it into the cells which are deficient. And that is every cell, and fat cells will take a lot of it. Kind of like a dry sponge sucking in liquid. So the goal isn’t to just take the RDA, it is to make sure the deficiency is redressed in every cell throughout the body, and then make sure you continue to get enough to keep those levels topped up optimally.
I would say (based purely on my own experience) that a daily dose of 1,600 won’t make up your deficit any time soon.