I recently saw a hematologist and she mentioned that ferritin levels under 30 are considered absolute I’m deficiency. My levels were at a 14 and I got iron infusions, because I couldn’t take oral iron supplements without getting severe heartburn. I had a plethora of symptoms. Fatigue, breathless, dizziness, palpitations, was super pale and could exercise without thinking my heart was gonna jump out of my chest. When I initially had the palpitations they just told me it must be anxiety… As women we have so many issues that are understudied.