I am not a doctor. You are not a doctor. 'There was another study' is a terrible way to self-medicate. Consequently, 'look up the studies yourself' is bad advice for self-medication.

If you do not have a deficiency, you can severely damage your health by taking high doses, like destroying your kidneys. I guess that happens because those kidneys need to wash out all the crap you feed your body that it doesn't want nor need.

5000 IU is not a low dose and should only be taken if you have a diagnosed vitamin D deficiency.