If i already take multivitamins, is it safe to also take vitamin c and vitamin d? not asking if it's necessary. just asking if it is safe to take

Safe and wise: I advise my patients to take 500-2000 mg of Vitamin C 2x/day, though larger amounts are also safe (the only issue is more than 5-10,000 mg a day may cause loose stools). I advise adults take 5-8000 iu of Vit D3 a day in fall and winter, year-round if you don't get much sun in spring and summer. Too much D can be toxic but usually at doses of 40,000 iu/day or more. See http://tinyurl.com/2chkcer