Chocolate whether emulsifying agents are added. Different manufacturers develop their own "signature" blends based on the above formulas, but varying proportions of the different constituents are used. The finest, plain dark chocolate couvertures contain at least 70% cocoa (both solids and butter), whereas milk chocolate usually contains up to 50%. High-quality white chocolate couvertures contain only about 35% cocoa butter. Producers of high-quality, small-batch chocolate argue that mass production produces bad-quality chocolate. Some mass-produced chocolate contains much less cocoa (as low as 7% in many cases), and fats other than cocoa butter. Vegetable oils and artificial vanilla flavor are often used
Chocolate milk in the intestine. However, it is present in small enough amounts that the effect on calcium absorption is negligible. As chocolate contains relatively small amounts of oxalate, it is unclear to what extent chocolate consumption affects healthy people with calcium-rich diets. In a 2008 study, participants who consumed one or more servings of chocolate on a daily basis had lower bone density and strength than those participants who ate a serving of chocolate six times a week or less. Researchers believe this may be due to oxalate inhibiting calcium absorption – but it could also be due to sugar content