My grandma went to the ER due to feeling nauseous and confused and they concluded it was Vitamin D toxicity from supplementation. She heard online that it’d help her avoid catching the flu.

Just a reminder that you should get a blood test and advice from a medical professional before taking anything above the daily recommended amount.

I agree 100%. But even with a blood test you need to be careful! I was taking 1000iu (doctors orders after a blood test) for about a month and it made my calcium spike above the normal range. I have freaky genes when it comes to Vitamin D and should have been taking more Vitamin K7 with it. But I now get it all from seafood, mostly salmon, since salmon also contains calcitonin [1].

[1] Evidence that calcitonin stimulates 1,25-dihydroxyvitamin D production and intestinal absorption of calcium in vivo.

https://pmc.ncbi.nlm.nih.gov/articles/PMC423580/

They were only prescribed 5000 IU? I was prescribed a dosage of 60,000 IU to treat my Vit. D deficiency!

60,000 IU per day or per week?

5,000 IU is most likely a daily dosage in this instance.

It was indeed per week, for 8 weeks. If it is 5000 IU, how many days do they usually prescribe it for?

Most likely the rest of their life.

5000 IU is largely the minimum effective dose for supplementation. The FDA still recommends less than half of this, and it is a shame.

Disclaimer: I take 5k IU a day due to the past 2 decades of research on the efficacy.

A doctor who has written a good series of article on Vitamin D advises to be cautious about taking it "for life" - https://www.devaboone.com/post/vitamin-d-part-2-shannon-s-st... ... See also How long does it take for vitamin D to work? - https://www.drugs.com/medical-answers/long-vitamin-d-work-35...

The first link aligns with what I know about it: above 70 ng/ml is where side effects start happening. I stay below 70 with 5000, but for other people, they may need less or even more, depends entirely on where you live, and other factors that are known to burn through Vitamin D (such as being overweight or drinking caffeinated beverages or experiencing high stress).

Based research I've seen, for optimal wakefulness and cognitive ability, 50-60 is optimal, below 40 is too low, above 70 is too high.

You may have to adjust dosage over time to dial this in.

Is this how you chose your username?

It's amazing to get tested and thinking you're heavy dosing and when tests come back it turns out you're barely in the green (low).

In my case, with 8 doses of 60,000 IU / week, I am no longer deficient, but the blood test in the 9th week also revealed that I have slightly crossed the margin of safe levels (borderline toxicity) for Vitamin D.