I have been making baby cereal powder by grinding rolled oats, flax seed, and hemp seed into a powder. I prepare this cereal by adding water and heat.
Many commercial powdered baby cereals (and general breakfast cereals) are iron-fortified.
What can I add to my homemade dry powder to fortify it with iron?
Note: Please hold off posting any opinions. I'm looking for factual answers with links to reference data.