What Minerals Are Needed For Absorbing Calcium?

Calcium, the most abundant mineral in the body, is an extremely important nutrient. Not only is calcium an essential element of bone structure, but it also is necessary for muscle contractions, nerve signaling, and dilation and contraction of blood vessels. Several factors can influence the absorption of dietary calcium. No other minerals are necessary for absorption, but other dietary factors play a role.

Vitamin D

In general, calcium absorption from food sources is relatively low. On average, the gut is able to absorb 30 percent of ingested calcium. One of the most important nutritional requirements for maximum calcium absorption is vitamin D. The active form of vitamin D regulates the transfer of calcium across the cells of the intestinal wall. Without adequate levels of vitamin D, the body is unable to absorb calcium.

Calcium Intake

The amount of calcium ingested also affects the amount that is absorbed. Absorption is inversely related to intake, meaning that as calcium intake goes up, absorption decreases. If you take very large doses of calcium, the excess calcium will pass through your digestive system, then excreted. To ensure your body gets the calcium it needs, spread out your calcium intake over the course of the day.

Inhibitors of Absorption

Some food components can inhibit absorption of dietary calcium. Oxalic acid, which is abundant in spinach, collard greens, sweet potatoes, rhubarb and beans, binds with calcium, making it unavailable to the body. Phytic acid, an element of dietary fiber, also binds with calcium. Phytic acid is present in high-fiber whole grain foods. High sodium intake does not affect calcium absorption, but it does increase the loss of calcium through urine.

Recommendations

Though several factors affect the body's ability to absorb calcium from food, absorption is believed to be adequate when an individual consumes a healthy mixed diet. Your goal for intake should be the Recommended Dietary Allowance, which is 1,000 milligrams for adults and 1,200 milligrams for adults over 50. Get your calcium from dairy sources, soy products, dried beans, broccoli or kale spread throughout the day.