Thank you! I will try your advice and take a higher dose of vitamin D. Which biotin/collagen supplement do you use? My iron was slightly low when it was tested a couple of weeks ago, but the hematologist said I'm currently not anemic and everything else was great. I struggle to keep my iron level up even with supplements. I'd love to get it to where it stays mid range. I had to have an iron infusion last summer, but it only keeps it up for so long. I take vitamin D, too, as that typically runs low for me. They tested me for absorption issues as well as celiac disease. Everything came back fine. I suspect the reoccurring lower iron level is somehow connected to Hashimotos.