While we have started taking vitamin D, I'm reading that the recommended dosage should be closer to 1000 IUs and do see some taking as much as 10x this amount daily. Unlike vitamin C that is water soluble and your body will get rid of any excess amount, vitamin D is fat soluble, so excesses will get stored and can cause issues if levels are high enough.
It would suck if you were taking something to be healthier and it caused more harm than good. Unfortunately blood tests for levels of vitamins are not part of normal yearly physical bloodwork (at least for me), so hard to tell.
Another thing I was reading is that vitamin D3 should always be supplemented with vitamin K2 to get the most out of the D3. Tumeric is kind of like that and is recommended to be taken with a black pepper extract.
