I take a calcium supplement that also has 200% of the RDA for D3. Back when this thing started - February or March - a doctor at our church told everyone to take zinc. He was popping zinc tablets himself. So I've been taking that, too, though not on a daily basis. Along with my O+ blood and lack of underlying conditions of any sort, I'm not too concerned.
200% of the RDA for D3 isn't all that much. It greatly depends on your daily exposure to sunlight. For a long time the RDA was 200 IU, then 400 IU and now I believe it is 600 IU.
I take 5,000 IU a day. Many doctors recommend between 2,000 and 5,000 a day.