Thanks for visiting! My goal here is to discuss the latest scientific research to separate the good from all that "guff" in nutritional sciences and all aspects of human health. Because the more you Know, well...the more you Know!

Looking for a specific post? You can browse the Most Read Posts, the Blog Archives, or use the Search function in top left of this page. Thanks for your support and stay healthy!

Monthly 3D Poll


Most Cost-Effective Way to Reduce Premature Death? Double Vitamin D Levels

This is getting a little ridiculous...this is the third study on vitamin D I'm covering in three days, so even if I come across another study tomorrow, I'm not going to cover it because you should know by now, how important this nutrient is for all aspects of health.

However, before I get to the study... the answer to my riddle from last week...

If you've tried to guess -- or even better, posted an answer -- to the riddle, the answer, as a couple of commenters have figured out, was water... the letters "H to O" were listed on the barrel.

I got this from an interactive story app I downloaded on my iPhone to read with my oldest son last year while he was learning to read. That was a tough one for us.

Well, on to discuss this study on vitamin D, where the goal was to estimate the reduction in mortality rates for six geopolitical regions of the world under the assumption that serum 25-hydroxyvitamin D (25(OH)D) levels increase from 54 to 110nmol/l (21.6 ng/mL to 44 ng/mL).

To make a long story short, the results showed a reduction in "all-cause mortality rates" ranging from 7.6% for African females to 17.3% for European females. Reductions for males averaged 0.6% lower than for females. The estimated increase in life expectancy is 2 years for all six regions studied.

Considering the low cost of vitamin D supplements, or the fact that "smart" exposure to UVB rays from the sun is free, it's one of the easiest ways we can improve or maintain our health.

Most vitamin D experts are saying 5000 IU daily from supplements is what is needed to ensure the whole body has enough of this essential nutrient. Apparently, according to surveys, even those those doctors who take a cautious and conservative approach by only recommending 2000 IU/day for their patients, are taking 5000 IU/day themselves. Hmmm...

In the ideal situation, when taking large doses of vitamin D3 as supplements, you'll want to get a product that contains a little vitamin K2 as well, or in the absence of a D3 product that contains some K2, I would advise you take some K2 separately. This is because vitamin D increases the absorption of calcium by the intestines. Vitamin K2, will help maximize the calcium's benefit to bones, while minimizing the risk of calcium's undesirable side-effects like arterial calcification or kidney stones (as discussed in previous posts).

Source: An estimate of the global reduction in mortality rates through doubling vitamin D levels

Related posts:
Click HERE to subscribe to Know Guff by email


  1. Do you have a suggestion for how much K2 is needed? I know that Now Brand D3+K2 has 1000 IU Vitamin D3 + 25mcg K2 but I do not know where that ratio came from. I also see references to the Japanese taking up to 45mg of K2 which would be absurdly expensive since it is sold in microgram amounts as far as I can tell. How much K2 do we need to fully activate vitamin K dependent proteins?

  2. Hi Peter,

    I'm not entirely sure myself, and I believe it's definitely related to type of vitamin K being used. The 45 mg you talk about was for bone health using MK-4.

    Where I live (Canada), Health Canada limits the amount of vitamin K companies can recommend (as a supplement) to 120 mcg. Of course this looks to be subtherpeutic if taking MK-4.

    This is likely the reason why most Canadian brands use MK-7, which seems to be therapeutic at doses as low as 45 mcg.

    I remember reading one study that used MK-7 and when they looked at osteocalcin (as an indicator of vitamin K status), what they found was that 45 mcg of MK-7 daily reduced the amount of uncarboxylated (inactive) osteocalcin by about 40%. According to the researchers, this 40% drop was sufficient to reduce the risk of fracture to a significant degree.

    There have been other studies that have showed varying doses as being sufficient, therapeutic, or optimal. However, I think it's still too early in the game for anyone to come to a definitive conclusion.

    Personally, I take about 140 - 200 mcg/day of MK-7 (this is an estimate since I take drops and don't really count the drops). Of course, there are days where I'll not take any, or take a lot less than 140 mcg...but also because MK-7 has such a long half-life compared to K1 or MK-4, I feel I don't need to be so diligent in consistent dosing.



Please use your name or alias. Due to a large volume of spam comments (as "Anonymous") all comments from "Anonymous" will be automatically deleted. Thanks.