Do prenatals or men taking multivitamins help you conceive??

I just don't see how. Has anyone or their SO tried for a long time started taking prenatals/men's multivitamins and conceived soon after? I feel like we've tried everything :( scared to do <a href="https://glowing.com/glow-fertility-program">iui</a> or <a href="https://glowing.com/glow-fertility-program">ivf</a> cause it probably won't work for us like everything else