Could an iron deficiency cause my Mom's dementia to worsen?

Low oxygen to the brain can cause the symptoms of dementia, so I imagine that low oxygen could also make symptoms worse for someone with dementia. Iron is essential for hemoglobin that carries oxygen to the cells. So if the iron level is low enough, there isn't enough oxygen delivered.

Along with taking the iron supplement, you may also want to invest in a pulse oximeter -- the little meter that clips on your finger. This will let you know how well you're doing at getting the O2 levels up. It will also let you see if there is any relationship between the O2 and amount of confusion. They are handy little things and don't cost much. I think mine cost about $20 on Amazon.

In my experience ANY less-than-optimal health condition caused increased dementia symptoms. If you mom has anemia I think treating it is worthwhile. Whether that should be a pill or a shot or some other approach I am not qualified to say. But getting the anemia addressed is a good idea.

Iron pills can make her constipated. Constipation will make her cranky. Ask the MD about a B12 shot instead of iron.