Space Colonies - Not Enough Iron (YA?)

For some reason, colonies further from Earth have less iron, and it gets worse the further from Earth. This causes nutritional and other social problems. Protagonist is son of the leader of an early colony who is leading movement to fix things. Kinda like Dune for kids.

I vaguely recall protag was genetically engineered because his mother kept having miscarriages due to lack of iron. Maybe in secret from the father (ie secretive trip off world while pregnant).

Read it in the early or mid 1990s. Maybe about the same time I read Prince Ombra.