Chocolate: Does it impair calcium absorption?

Chocolate contains oxalate — a naturally occurring compound in cocoa beans — which in large amounts may inhibit absorption of calcium. However, the amount of oxalate in chocolate is small, so any effect on calcium absorption is likely to be very minimal. In fact, a small study published in 1989 reported no difference in calcium absorption between plain milk and milk flavored with chocolate. Also, many chocolates are now fortified with calcium.

Oxalate is found in varying amounts in many other foods, such as spinach, sweet potatoes, okra, kale, collards, chard, berries and tea.