I agree, it is confusing. I started off with items from this site, such as a bariatric multivitamin capsule that contains iron. I also got two different flavors of chewable calcium citrate from bariatric advantage. Although I was able to swallow the capsule, the chewable calciums were very large, gummed up in the back of my throat which made me gag, and tasted gross. My surgeon’s office recommended Citracal petites. I was able to swallow those.
Within a month, however, I had to change up everything. The iron in the capsule made me vomit, so I purchased a slow release iron tablet upon a pharmacist’s advice. This has been a godsend. I had to find a standalone multivitamin without iron, which I found at a grocery store. Then, The Citracal was making me vomit, so I found a liquid calcium citrate, not great tasting but I can definitely tolerate it.
Do some reading, look at reviews, and start with a small supply of what you think will be good for you: multivitamin, iron, and calcium citrate. Take them at the start of a meal to help prevent stomach upset. If something doesn’t feel right, contact your doctor or nutritionist, and there are so many other options! Good luck!