ORIGINAL: Red Lion
Garlic is suppose to be helpful in somewhat reducing cholesterol.
As is cinnamon. Never been proved in an official medical study, but I've seen it work for numerous patients in the past. As a corollary, I've also seen it not work more often than it works so I reserve it for patients with high cholesterol who don't want to take a med or who have adverse reactions to cholesterol meds.
Zinc is indeed a component in semen, whether or not consuming more zinc would actually help the quality of your excretions is not something I'm familiar with, but I doubt it would make much difference. Zinc has been shown to be involved in wound healing.
As far as claims about B1, garlic or zinc repelling mosquitoes, none has any verifiable scientific proof behind it. My mom had me take a B1 vitamin daily as a kid in the summer and it never seemed to do me much good. My thoughts are that you're better off buying Off and using bug zappers and citronella candles that are proven to work than buying vitamins that may or may not work.
Garlic, zinc, and B1 in excess of what your body needs (you get plenty of all of these from a normal diet) will mostly be excreted in your urine or your feces which is why many biochemists say Americans have the most expensive urine in the world. As is mentioned in Rebel Hog's link, we already exceed the recommended daily value of 99% of the vitamins our bodies need long before we take any un-tested pills.
For anyone considering spending any money on any kind of vitamin or supplement, I highly recommend reading the FDA mandated label on all vitamin and supplement containers that says "This product not intended to prevent, diagnose, treat or cure any disease of condition."
My question is this: If it doesn't treat, prevent or cure anything and isn't intended to do so, why pay $5 a bottle to take it?
Something else to keep in mind; it took very little effort aside from paying for permits and minor inspections to get Ephedra on the market and it took 20 deaths attributed to it for the FDA to pull it all the while "Health stores" were touting it's miracle powers and safety. How safe are the rest of the supplements on the shelves at GNC?