My Roomate Is 32 Years Old, She's In The Hospital

My roomate is 32 years old, she's in the hospital right now on a strong anti-biotic called cloxicillan dextrose 5%. She's fighting a tough infection right now and my question is if it's safe to give her natural things to help her body fight better. A healthier body in my mind can fight any infection better than an unhealthy body. Can I give her Milk Thistle, omega 3's, calcium, magnesium, holy basil and he B and D vitamins?