I take a multivitamin daily + D3 suppl for a total of 1800iu. But is it ok to take extra supplementation of vitamin E and vitamin c? What about zinc?

Yes - depends a bit. Most adults need 5-8000 iu of d3/day to achieve optimal levels of 50-80. Most multivits have 30-60 iu of e but there are benefits to taking 400-800 iu of e a day, but only as natural e with mixed tocopherols- Alpha tocopherol alone may be hazardous.I advise people take 1-2, 000 mg of c 2x/day. Too much zinc can be toxic but doses up to 40 mg/day are safe-but balance with copper in a 10-15:1 ratio.