Vitamin yucky
What are the problems they are causing you?
Are you sure you need to take biotin and a B complex? biotin deficiency is super rare so it is very unlikely you actually need to take biotin, though of course you should ask your doctor if you're not sure. The ASMBS says a B complex is optional. Now, if you are low in some of the B vitamins, then you should probably take it, but otherwise, maybe you would prefer to opt to skip it, at least for now. Again, you should ask your doctor.
Before someone jumps on me for telling you not to take your vitamins, that is NOT what I am doing. I am suggesting some possible options and recommending you discuss them with your doctor.
You can purchase dry D3 in a very large dose, 50,000 IU, and take it a couple times a week (how often depends on your labs) instead of taking it every day. I use the Tender D3 50,000 from vitalady.com and it is a very small capsule and easy to take. I take it three times a week, based on my labs - you might need it more or less often. If you're not sure how often, talk with your doctor.
What type of iron are you taking that's causing you problems and what problems is it causing? Carbonyl iron is a lot easier on the tummy than ferrous sulfate and the other ferrous salts and rarely causes constipation.
Please note: I AM NOT A DOCTOR. If you want medical advice, talk to your doctor. Whatever I post, there is probably some surgeon or other health care provider somewhere that disagrees with me. If you want to know what your surgeon thinks, then ask him or her. Check out my blog.