Calcium, a silvery metallic element and one of the alkaline earth metals is the most abundant metallic element in the human body. It is the fifth most abundant element in the Earth's crust and is essential for physiological functions. Calcium is a mineral that is essential for bones, to increase bone mineral density and improves the effectiveness of osteoporosis medications. Calcium has also been shown to decrease bone loss in postmenopausal women. According to a Woman's Health Initiative trial, incidences of hip fracture decrease in older women who supplement calcium in their diet.

As we age our calcium intake naturally increases due to the reduction of intestinal calcium adsorption after menopause for women. Post menopausal women also have reduced acid production in the stomach and lower intake of vitamin D therefore calcium citrate supplement should be taken increasing calcium levels to offset the lower intestinal adsorption and less efficient conversion of calcium by the kidneys. The national academies of sciences guidelines for calcium intake for women suggest 1,000 mg per day for women between the ages 31-50 years old; women older than 50 should take upwards of 1,200 mg calcium per day. The problem however is, most postmenopausal women in today's society either have poor diets, and or are vegans. The elderly may not have adequate calcium intake because of their dietary lack as well. In the USA, postmenopausal women have dietary intakes of around 600 mg per day which is below the recommended amount.

Calcium in the blood has roles in muscle contraction, nerve-impulse transmission, blood clotting, milk production (women), hormone secretion, and enzyme function. If there is a calcium deficiency in the diet, calcium is pulled from the bones and teeth so other body functions can continue. Therefore, it is important to calculate the amount of calcium supplementation you need. The first thing is to estimate your current dietary intake of calcium outside of any supplementation that you may take. Most women eat 2 to 3 meals a day so you can assume you get 250 mg calcium per day not counting dairy foods or calcium fortified foods. A lot of women take an additional 300 mg calcium by one serving of dairy products. If you drink one glass of milk then your total intake is calculated to be 550 mg calcium per day. Therefore you need an additional 650-950 mg per day.

Since we have determined that our intake of calcium is lacking, the next question you may have is what form of calcium should I be taking in a supplement to meet my needs? There are a few different forms of calcium found in your local health food store such as (i) calcium carbonate and (ii) calcium citrate. Some women who take calcium carbonate suffer from constipation, nausea and indigestion. Calcium carbonate is best taken with food because of improved adsorption. Calcium citrate on the other hand is best taken on an empty stomach for improved adsorption. Calcium citrate is less likely to cause constipation, nausea and indigestion therefore it is the better choice for older women with lower stomach acid and lower intake of vitamin D. Furthermore, some research has shown that combining Vitamin D with calcium can improve adsorption.

Calcium supplementation is extremely safe, even in quantities up to 1,500 mg per day from both diet and supplements there is no risk of increased kidney stones. However, calcium intake greater than 2,500 mg per day from diet and supplementation should be avoided unless recommended by your health care professional.