Your body absorbs iron and vitamin A from meat and animal products way better than the versions found in plants.

We analyzed one assertion on this topic and found it supports the idea that heme iron and retinol from animal sources are absorbed more efficiently by the body than non-heme iron and beta-carotene from plants [1]. This single piece of evidence suggests that when you eat meat, eggs, or dairy, your body may take up these nutrients more easily than when you get them from plant foods like spinach, beans, or carrots. Heme iron is the type found in animal tissues, and it’s structured in a way that seems to pass through the gut lining more readily than non-heme iron, which comes from plants and can be blocked by other compounds in food like fiber or phytates. Similarly, retinol — the active form of vitamin A in animal products — can be used directly by the body, while beta-carotene from plants must first be converted into retinol, and that conversion doesn’t always happen well in everyone. What we’ve found so far is limited to just one assertion with no opposing studies to compare it against. That means we can’t say how strong or consistent this difference is across different people, diets, or health conditions. We also don’t know how much of an impact this has on overall nutrient status in real life. The evidence we’ve reviewed leans toward the idea that animal sources of these nutrients are more readily absorbed, but we don’t have enough data to say how much more, or whether this matters for people eating balanced diets. If you’re trying to get enough iron or vitamin A, it may help to include some animal-based foods — but it doesn’t mean plant sources are useless. Pairing plant iron with vitamin C, for example, can boost absorption, and cooking or fermenting plants can help too.