Some foods that have low calcium values are legumes, mustard greens, concentrated orange juice, grains, raw kiwi, dried sunflower seeds, bok choy, brine-packed corn, kale and collard greens. One-half cup of cooked legumes has between 15 to 50 milligrams of calcium, while one cup of raw kiwi has 50 milligrams. One cup of orange juice made from concentrate contains 20 milligrams of calcium.
A vegetable like corn has a low value of calcium when compared to another vegetable like spinach. For example, a cup of corn packed in brine has 10 milligrams, while an equivalent amount of cooked spinach contains 240 milligrams, according to the University of California San Francisco Medical Center.
The National Institutes of Health Office of Dietary Supplements relates that most grains do not contain high values of calcium unless the product has been fortified. However, grains and their by-products still are a source of small amounts of this mineral because people tend to eat these products regularly. An example is a slice of wheat bread that has 30 milligrams, and most people may have bread on a regular basis.
Calcium is an important mineral in the body that is necessary for strong and healthy bones. People of all ages require calcium and should get the recommended dietary allowance (RDA) of calcium every day either through diet or supplementation. For adults between the ages of 19 and 50, the RDA is 1,000 milligrams of calcium a day. The foods that are highest in calcium are dairy products and vegetables like spinach.