“With anything chronic or worse like cancer, or if you are closer to 300 lbs, take 10,000 IU.”
That could kill some people.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897580/
[Read under “Possible Deleterious Effects of Vitamin D in Cancer Patients.”]
No, it couldn’t kill some people. I stand by getting one’s blood level of d at 60, higher if fighting something chronic, but your study does suggest too high, like 90-100, might be deleterious in cancer patients. Non conclusive. But if you do all the testing and titrating your vitamin D3 dosages, then retesting in two months, flu season will be over. So while one SHOULD Get the blood test now, supplement if you are under 60, and test again in 2 months, it’s a lot of work when supplementing 5000 IU should get you through flu season for the time being.
But if you have cancer, I’d say on the basis of your study, stick to only 5000 IU if you are NOT getting your blood levels tested.