Hi Heather @heathert, the research on iron supplementation and mycobacterial growth has been contradictory. More of the research has been done in Africa with populations regularly having high iron loads in their diets, and even overloading of dietary iron on a frequent basis. in those studies, people tended to have poorer outcomes with mycobacterial infections.
Some other studies have found conflicting results -- iron supplementation even during TB had no effect on the mycobacterial burden in the lungs.
However, recent research with other populations found that if you routinely have low levels of iron in your diet, and have had some degree of anemia -- for example many vegetarians -- then supplementation with iron has no effect on increasing mycobacterial growth.
So if you continue to be a vegetarian, you should be safe to take iron supplements.
(See "Iron Supplementation Therapy, A Friend and Foe of Mycobacterial Infections?", R. Agoro and C. Mura, 2019 -- Pharmaceuticals 2019, 12, 75; doi:10.3390/ph12020075 http://www.mdpi.com/journal/pharmaceuticals).
Hugs, Annie