Which vitamin supplements should i take i am already 75mg thyroxine and 50mg of fluoxetine daily?

None: If you eat a healthy diet, you don't need any vitamins. In fact, vitamins cannot be taken with two hours before or after thyroxin or they will alter it's absorption. Make sure you're taking brand name T4 replacement as the generics are unreliable.

If depressed . . . : Depression and hypothyroidism do often run together, but thyroxin alone may not eliminate your depression. For my depressed patients i often suggest a high epa fish oil such as omega-brite, so that they can have at least 1-2 grams epa/day in only 3 capsules. Take this with full meals. Also, consider a multivit that contains 1000mcg l-methylfolate & 1000mcg B12 (methylcobalamin) daily as well.