Calcium is a trace mineral essential for the proper functioning of all living organisms and an important constituent of bone, teeth and shells. It is an important nutrient of a healthy diet. Sufficient intake of calcium helps to build stronger bones. It helps to build denser bones early in life and keeps bones strong and healthy even later in life.

Below is a chart of recommended daily allowance of calcium for each age group by IOM

     Age                                          Amount of Calcium per Day

0–6 months                                                 200 mg
7–12 months                                               260 mg
1–3 years.                                                    700 mg
4–8 years.                                                    1000 mg
9–18 years.                                                  1300 mg
19–50 years.                                                1000 mg
51–70 years (male)                                     1000 mg
51–70 years (female)                                  1200 mg
71+years                                                       1200 mg

Dietary Sources of Calcium

Dairy products, such as milk, yogurt and cheese, are well-known sources of calcium

Beans, especially soybeans

Seaweeds such as wakame, hijiki and kelp.

Nuts and seeds such almonds, hazelnuts, almonds, pistachios and sesame seeds

Blackstrap molasses

Figs, quinoa, okra; rutabaga; broccoli; dandelion leaves; and kale.

Spinach, rhubarb and chard, amaranth, collard greens, chicory greens.

Several foods and drinks, such as soy milk, breakfast cereals, breads, tofu and orange juice are often sold after fortified with calcium.

Factors that Reduce the Absorption of Calcium

Vitamin D is an essential nutrient needed for calcium absorption. So, a deficiency in vitamin D leads to low level of calcium and that affects bone health. Some vegetables may contain oxalic acid that binds calcium and reduces its absorption. These vegetables include spinach, rhubarb, chard, amaranth and collard greens,

Calcium deficiency can lead to osteoporosis, a condition in which bone deteriorates and fracture readily. 99 percent of calcium in our body is present in the bones and teeth. Over-retention of calcium can cause hypercalcemia (elevated levels of calcium in blood), impaired kidney function and decreased absorption of the minerals.