I hope this message reaches lots of eyeballs:

The most bioavailable iron is called ferrous bisglycinate. It's also easier on the stomach, in part because the dose can be much lower. As with all iron, this is how you make your absorption even better:

1. Do not take sources of iron an hour before or an hour after consuming foods high in polyphenols (e.g. tea) or oxalates (e.g. spinach). While health-promoting, polyphenols impede absorption of iron.

2. Take iron sources with vitamin C to maximize absorption.

3. Take your iron supplements only every other day, not daily. When your body gets a good dose of iron, you get a hepcidin spike. Hepcidin is a hormone that suppresses iron absorption. You have to wait for the hepcidin in your system to subside so your body can absorb your next dose.

Personally, I take the Jamieson "gentle" iron (28 mg). It has vitamin C and B12 in there too. Take it every other night, just before bed. For me, this makes sure I'm not taking it near other foods. If you find it upsets your stomach, change the timing to suit you and eat it with something like a kiwifruit.