Has anyone done a RCT of D3+K2? K2 seems to be important in the absorption of D3. Another aspect that bothers me with these studies is that we’re simply supplementing the vitamin D, seemingly without measuring the change in blood levels. I took 2000IU (+K2) a day for many years in between testing my blood levels and still had <30ng/ml and had to go up to 5000IU/day. I’d like to see some further study.

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cj a day ago | parent | next [-]

K2 is also known to prevent problems with calcium build up which can happen if Vitamin D is dosed too high. I personally would never take Viramin D without K2 alongside it.

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fridder a day ago | parent | next [-]

One problem: folks that are on blood thinners shouldn't supplement with vitamin k

	▲	anjel 21 hours ago \| parent \| next [-]
		Vitamin k and k2 are not at all the same with respect to blood thinning
	▲	moffkalast a day ago \| parent \| prev \| next [-]
		If you are on blood thinners you probably shouldn't be taking common advice on anything tbf. Or diabetic. Or heavily allergic. Cause you will straight up die.
	▲	freehorse a day ago \| parent \| prev [-]
		only if the blood thinners taken are vitamin k antagonists (not all are)

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throwaway613746 a day ago | parent | prev [-]

[dead]

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brandonb a day ago | parent | prev | next [-]

TARGET-D is an in-progress study that supplements vitamin D based on blood levels (your idea).

	▲	nradov a day ago \| parent [-]
		I think that study is already concluded but the results haven't been published yet. https://clinicaltrials.gov/study/NCT02996721?tab=study

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odie5533 a day ago | parent | prev | next [-]

Were you taking hard tablets? And were you taking them with a fatty meal?

Those are both very important. I take a Vitamin D + K2 softgel with a meal that has some fat in it.

	▲	aaronbrethorst a day ago \| parent [-]
		Costco sells D3+K2 softgels! Great price, of course. I started taking them at the recommendation of my podiatrist after I broke my foot last winter (third metatarsal fracture, specifically, ouch).

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nullc a day ago | parent | prev | next [-]

> I took 2000IU (+K2) a day for many years in between testing my blood levels and still had <30ng/ml and had to go up to 5000IU/day.

Likewise, 23ng/ml while taking 2000iu/day of dry vitamin-d.

Switched to 5000iu +K2 in MCT oil, -- 8 months later I'm at 64ng/ml.

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icedchai a day ago | parent | next [-]

I switched from 2000 to 5000iu about 8 years ago. My levels went up similar to yours, but I don't feel much different!

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rbjorklin a day ago | parent | prev [-]

Any noticeable difference how you feel health wise? Energy levels? Mood? Sleep quality?

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_0ffh a day ago | parent | next [-]

Not the same person here, but a data point nonetheless. Before supplementing D3 I had a cold basically every year, sometimes twice a year. Since I brushed up my levels I average 1 cold in 6 years.

	▲	ww520 a day ago \| parent [-]
		Oddly, since the Covid time, I haven't caught a cold or flu once. I'm not sure it's the vaccines, the flu shots, or the less physical contacts on things overall. I still go to crowded places from time to time, like plane or train rides. May be the population in general have less cold or flu virus overall to go around.

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nicman23 17 hours ago | parent | prev | next [-]

for me, i was so deficient that i would notice it the next morning. also probably not a placebo as the D supplement i am taking is not something my mind goes to 7 am pre coffee lol

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nullc a day ago | parent | prev [-]

Unfortunately too many other changes happened at the same time. I am enormously healthier now (in numerous measurable as well as subjective ways) but it may be that the D levels played no role.

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amelius a day ago | parent | prev [-]

What I found was that I had to dissolve vit D under the tongue, not immediately swallow it.