I had covid (the 1st time) in Aug '21. A couple of mos. later, my hair started falling out in giant clumps/handsful. This continued for at least 3 mos. Then, it started slowing down. In the meantime, I had begun taking biotin per recommendation by my sister, who is a cosmetologist. I tried to tell myself it was just daily shedding adding up because I'd been too weak/sick to brush or wash my hair very often, but I knew there was no way that could account for all of the hair loss. When I finally went in to the salon for a trim about 6 mos. after I first got covid, my stylist was shocked to see how thin my hair had gotten. I had always had very thick hair before this. She said she could see my scalp! My son told me the same thing. I almost cried. But, my hair continued to regrow and, even though I got covid a 2nd time, my hair is back to its usual thickness again. My 2nd bout with covid was nowhere near as bad as the 1st. The 1st time, I had a fever for 11 days straight and couldn't eat almost anything at all for 2 weeks. This was too hard on my body and had caused my hair follicles to close up while my body focused on healing and surviving.

Like someone else said already, I, too, ended up with extremely low ferritin (a protein that stores iron). I also had low B12. The low ferritin, combined with a fungal ball in my sphenoid sinus that nobody discovered for almost 2 yrs, caused me all sorts of neurological issues, too ... hand tremors, 24/7 vertigo that lasted for 5 mos until I began taking iron supplements, continued vertigo multiple times a day for the next 1 1/2 yrs until an ENT told me I needed surgery to remove the fungal ball, dailtly excruciating and debilitating headaches, tingling all over my body, mobility/gait incoordination so bad I had to use a cane & walker for many months, confusion, heart palpitations, etc.

Good luck on the hair loss and any other long covid symptoms. Hang in there. Keep researching, pressing forward, getting 2nd & 3rd opinions, & pushing for testing until all of your issues are resolved. You won't regret it!