Hair needs enough building material. Low protein intake, low ferritin or vitamin D deficiency can add diffuse shedding on top of genetic hair loss.
In Lithuania, vitamin D is often discussed because of long low-light seasons. Testing is still better than guessing, especially when several supplements are already being taken.
Iron status matters for many women, but men can also have relevant deficiencies. Blood work should be interpreted with a clinician, not isolated from symptoms.
Correcting a deficiency will not replace a transplant, but it may make the treatment plan cleaner and easier to evaluate.