@godincenter Up to Date shows a reference range for his age of 11-13.5 g/dL, so he’s just below the target range. Iron-deficiency anemia is pretty common in 1 year olds, and isn’t dependent on what he ate yesterday. In general, people store a little extra iron when it’s plentiful and during short periods of lower iron intake can dip into their reserves, and you can be iron deficient without fully reaching anemia if your reserves are low. You measure the reserves by looking at blood ferritin level. So the bottom line is that if he’s anemic, you might be able to get his hemoglobin levels up by 0.3 g/dL to normal within a few days, but you’re not going to fix his ferritin levels and iron reserves without a larger change. It’s also worth asking your pediatrician if they want to do follow-up testing - things like B12 deficiency can also cause anemia, as well as genetic conditions and the like, so you want to know whether it’s actually iron deficiency or something else.
There are other nutrients and foods that can reduce your ability to absorb iron, like dairy, while vitamin C increases your iron absorption, so it could be in part due to what he’s eating with the iron-rich foods. Also, heme iron (from animal sources) is easier to absorb than non-heme iron (plant sources, supplements, etc).
As for things like behavior disorders and low IQ with iron deficiency, there’s some evidence for long-term sleep trouble and resulting behavioral issues, but the effect size seems to be measurable but small, and there are confounding factors like medical care in general, parental socioeconomic status, parental IQ, other environmental factors, etc. I wouldn’t be concerned about long-term effects so much as I would short-term - having been anemic, it certainly affected my mood, energy levels, mental acuity at the time because I was so fatigued, sleep, and anxiety levels. Since he can’t really tell you how he feels, you definitely want to address it with his pediatrician to make sure he’s feeling and functioning at his best.
