Question: Do oxalates interfere with the absorption of calcium?
Is it true that that the oxalates in tea/milk or chocolate/milk interfere with the absorption of calcium from milk?
Kehkashan - About.com User
Answer: Yes, the oxalates in tea will interfere with the calcium absorption from the milk. The oxalate in the tea binds to calcium and is removed through the digestive tract and not absorbed. Chocolate also contains oxalic acid which will bind up some calcium.
A cup of tea may only have a small amount of milk added, so the tea may bind up a fair amount of the calcium, but a glass of chocolate milk would contain a lot more calcium than oxalate and would still be a good source of calcium.
Sources: Charrier MJS, Savage GP, Vanhanen, L. "Oxalate content and calcium binding capacity of tea and herbal teas." Asia Pacific Journal of Clinical Nutrition 11 (4), 298-301. Brinkley L, McGuire J, Gregory J, Pak CY. "Bioavailability of oxalate in foods." Urology. 1981 Jun;17(6):534-8.
