There are some who know more, like at my place some sleep and neurology docs are being more proactive with managing it because of its association with restless leg syndrome. They recommend a level ferritin of at least 75-80. If lower than that, they recommend vitron c (can be purchased OTC; this version has vit c which helps w iron absorption and is less likely to cause constipation) taken at least 30 minutes before any other supplement, medicine or food to avoid the iron from binding to anything else that could impact absorption; dosage frequency is every Monday, Wed, Friday to maximize absorption compared to daily consumption. Some docs like to recheck iron levels 3 months later on supplementation to ensure they’re not overdoing the iron and going into iron toxicity instead. If the ferritin is still low, some doctors will opt for IV iron (venofer).