May not be good
Some vitamins have a very strong odor to them because of the way they are made.
Multivitamins and b complexes are notorious for this. It could also be that they are not well made. To check the effcacy of your vitamins, put them in regular vinegar. If they dont dissolve in 15 minutes, throw them away. They have no bio-availability. I recommend physician grade products, capsules are great.