Cacao is full of trace minerals and other nutrients. The exact mix varies depending on growing conditions, fermentation, and even grinding machinery. Unfortunately, cacao also contains numerous antinutrients: compounds that reduce our bodies’ ability to absorb things like iron and calcium from food.
On the one hand, chocolate contains copper, iron, magnesium, calcium, potassium, and zinc—all crucial, in small quantities, for our body. Some of those minerals come from the soil, but others may be deposited in chocolate by grinding machinery.
On the other hand, chocolate is high in antinutrients like flavonoids (yes, the very same beneficial chemicals from the previous section) and organic acids, which actually reduce nutrient absorption. As a result, it’s hard to tell what nutrients you’re really getting from chocolate.
Iron is a good example of this complexity. The iron in chocolate is more concentrated than chicken liver or beef. Unfortunately, chocolate—like all plants—contains mostly non-heme iron, which is less bioavailable than the heme iron in meat. So there’s plenty of iron in chocolate, but not all of it makes its way into your body. In addition, flavonoids and some organic acids can block iron absorption, so you’ll get even less iron from raw cacao or lightly-roasted chocolate. Not all organic acids block iron absorption, though; ascorbic acid actually assists with iron absorption.
Given the variability of cacao sourcing and processing, it’s very difficult to say for sure what nutrients you’ll ultimately get out of a given bean, let alone how your body will handle them.