Calcium

Calcium is the most plentiful mineral in the human body and it has several significant roles. It is one of the skeleton’s primary building blocks. We find more than 99% of the body’s total calcium is in bones and teeth, where it provides structural support. The rest is found throughout the body: fluid between cells, blood and muscles. Outside its function in bone, it plays other important ones: in secreting hormones and enzymes and regulating their activity, it is used to send messages throughout the nervous system, it is involved in blood clotting and it aids in blood vessel and muscle contraction and expansion, it also contributes to normal heart rhythm.

For these important processes to take place efficiently, body fluids and tissues must maintain a constant level of this mineral. The skeleton stores calcium and other minerals. If the blood content of this mineral is too low, the body replenishes it with calcium stored in the bones.

Calcium deficiency is not often detected because of the lack of symptoms. Often it is only detected when there has been an extensive amount of bone mass lost. Diets high in protein and sodium can limit the bioavailability of this mineral. As Americans consume more and more protein in their diet, they may be impacting their absorption of this mineral.

When the reservoir of calcium in your bone is depleted, bone fractures can occur even under minimum stress. Outside of its effects in bone, the risk of inadequate intake can lead to increased risk of high blood pressure. Some studies suggest that there is an increased risk of colon cancer linked with poor intake.

Osteopenia, often the beginning of osteoporosis, is also caused by deficiency of this mineral in diet. Bones are dynamic tissues and they are constantly going through a process of breakdown and deposition. As people grow older, the amounts of breakdown and deposition are altered. More formation and less breakdown happens during childhood. With older people happens the opposite. You get one shot to build the skeleton, and that’s during the period of rapid bone formation from age 11 to 24. If you miss this bone formation time you won’t have the chance to do it later in life.

In early-middle adulthood, breakdown and deposition are nearly the same. In aging adults, and particularly in post-menopausal women, bone loss surpasses deposition. This bone loss increases the risk for osteoporosis. Some studies suggest that within the first year after menopause, women can lose up to 7% of bone. Exercise and diet can help to reduce the loss. Make sure to include strength training to your routine.

Calcium alone doesn’t improve bone mass. Too little calories, too little vitamin D and the wrong form of exercise can contribute to bone loss in even young women. Deficiency can also lead to poor blood clotting.

What about excess? Excess intake of this mineral can lead to a condition called hypercalcemia. This condition is often due to excessive vitamin D intake and is rarely caused by diet alone. In individuals with cancer, hypercalcemia may be present due to cancer’s effect on the bone. Cancer can chew up the bone and release calcium onto the bloodstream. Hypercalcemia causes fatigue, depression, confusion, loss of appetite, nausea, vomiting, constipation, pancreatitis and increased urination.

Daily Recommended Amounts

Infant, 0–6 months	210 milligrams
Infant, 7–12 months	270 milligrams
Child, 1–3 years	500 milligrams
Child, 4–8 years	800 milligrams
Male, 9–18 years	1300 milligrams
Male, 19–50 years	1000 milligrams
Male, 51–70 years	1300 milligrams
Female, 9–18 years	1300 milligrams
Female, 19–50 years	1000 milligrams
Female, 51–70 years	1200 milligrams

Food Sources

1 cup cottage cheese, 2% fat	206 milligrams
3 oz sardines	325 milligrams
1 cup milk, 2% fat	296 milligrams
8 oz yogurt, fruit, low-fat	345 milligrams
1 cup broccoli, cooked	62 milligrams
1 cup navy beans	126 milligrams
1 cup kale, cooked	94 milligrams