I have been taking vitamin C and vitamin D together for a while. Is it bad? I take them everybody but sometimes I skip too.

C AND D. There should be no interaction taking these together as long as they don't bother your stomach. It is easier on the stomach lining if you take these after eating.
D+C together is ok. Vitamins can be taken together but like anything else you can take too much. Unless you have a known medical problem that requires more than the daily amount you do not need to exceed this amount. For a young person, 1000 mg of Vit. C and 1000 IU of vit. D3 would be enough. You will get the best benefit if you take the Vits. daily. Increasing Vit C around or with illness is helpful to immunity sys.
Vitamin C. half-life is 12 hours. So, take a does in the morning and again in the evening. Peace and good health. Taking it along w/D is fine. Your doc can check your D level to help you determine how much to take. Many folks used 5K dailly.
Should be fine. Taking vitamin C is great for your immune system and connective tissue. Vitamin D also helps with your immune system, mood and many other things. There is no problem taking them together.
It is ok. not a problem taking both vitamins at the same time each day. want to be careful with vitamin D as it is a fat-soluble vitamin and you can get too much of it. Most experts recommend 600-800 international units a day if your vitamin D levels are within normal limits. This can be checked easily by a blood test from your doctor. Vit C at 75mg a day for your age. Don't forget calcium 1000mg a day. .