ויטמינים כאוכל נפש

I would like to know if, considering the recent scientific findings regarding the definitively positive role vitamins play as a preventative against heart problems, cancer, etc., and considering that one takes these vitamins not as okhel nefesh, there is any reason one should be concerned with the kashrut of the capsules?

Kosher vitamins are often not as potent and always twice the price. Since this is a life-long undertaking, does one have to be mahmir if in principle the capsules are permissible even if they contain gelatin?