Each time you donate blood, you lose between 220-250 mg of iron. It may take up to 24-30 weeks for your body to replace the iron lost through a blood donation. That time may vary, depending on what your iron level was before donating and if you take iron supplements or multivitamins with iron.
AFAIK many people are fine (no symptoms) with having low iron levels.
You lose quite a lot of iron when donating blood:
AFAIK many people are fine (no symptoms) with having low iron levels.