Dinner deserves this pairing. Beans supply iron, but adding vitamin C-rich bell peppers can help your body absorb more of it, making an ordinary bowl work harder without requiring another supplement purchase. The pepper earns its place. If you already cook beans for their protein and fiber, this is one more reason to give them a crunchy companion.
Your gut needs persuasion. Beans contain non-heme iron, a form whose absorption varies with the rest of your meal, including compounds such as phytates that can bind iron and limit its availability. Vitamin C changes that. Also called ascorbic acid, it helps convert ferric iron into ferrous iron and keeps iron soluble, so more remains available for absorption in the intestine. No miracle multiplier applies. The size of the benefit depends on your iron stores, the amount of vitamin C, and what else shares the plate.
Keep the cooking simple. Spoon black beans over rice, fold chickpeas into a salad, or warm white beans with tomatoes, then add chopped bell pepper so its vitamin C arrives in the same meal. A little crunch helps. Because prolonged heating can reduce vitamin C, stirring peppers in near the end or serving them raw is a sensible way to retain more of it. Dinner is not treatment. If you have diagnosed iron deficiency, this pairing can support your diet but cannot replace prescribed care; for tonight, which bean dish gets the peppers?