Can alcohol abuse cause iron deficiency ? thank you

Possibly: alcohol itself can be toxic to bone marrow (where blood is made), but also can lead to blood loss from ulcers and varices (dilated veins) in the gut, leading to further or acute anemia, and poor diet often associated with alcohol abuse can worsen anemia. If with liver damage, can make factors in blood responsible for stopping bleeding become ineffective. Happy to consult but key is abstinence.

Not by itself: Alcoholics may have iron poor diets and may bleed from the stomach lining after drinking causing iron loss. This is why they are often iron depleted.