Dairy products, green leafy vegetables, tofu made with calcium sulfate, sardines canned with the bones, and calcium-fortified foods are good sources of calcium. Complete the statement about factors that affect calcium absorption. Calcium absorption is enhanced ______________.
a. when the body's need for calcium is high
b. as you get older
c. when you consume more than 800 mg of calcium at one time
d. by consuming high-oxalate foods