if sun has vitamin D, and sunblocks.....?

Yeah it blocks the production of vitamin D. But you only need about 20 or so minutes of unblocked sun about 3 times a week. It is nearly impossible to overdose on vitamin D pills. 2,000 IU (333%) a day is ideal. More than 10,000 iu a day reduces benefits after several weeks. A few million IU, accumulated over a couple months could be toxic. So if you spent thousands of dollars on 200 vitamin bottles and downed them all quickly then you might pull off a toxic amount.

You only need 30 mins of sun a day to get the recommend amount of vitamin D. That being said, the sunblock helps the skin because the damaging affects of UVA rays. Wearing the sunblock will not affect you negatively. Plus drinking milk is a good way to get vitamin d too.

Taking vitamin supplements is more complicated then people make it out to be. You can overdose on any vitamin.

The sun does not give off vitamin D. The sun makes our body to produce vitamin D. If we take vitamin supplements then our body will not produce the chemical vitamin. This is why supplements are not good for you. Most of my clients are Dr. and they won't take supplements because of this. They want to body to work as it was intended. This makes the immune system to work better which creates better health.