How bad is it consuming calcium with iron rich meals? How much does the amount matter. Any good alternatives for yogurt

I try to make iron rich melas

Breakfast example I make eggs with whole grain bread and

Oats, hemp seeds, walnuts, a bit of yogurt (because of probiotics) and something containing a lot of vit c

How bad is the calcium in the mixture.

Does the iron in the meal even get absorbed or does the yogurt totally kill it? What can i exchange it with?