Calcium

Calcium is the most common mineral in the human body. Calcium is an important determinant of bone health and risk of fracture or osteoporosis. Approximately 99% of total body calcium is in the skeleton and teeth and 1% in blood and soft tissues. Calcium has four major biological functions:

1. skeletal structure
2. electrophysiological (carries charge during an action potential across membranes)
3. intracellular regulator
4. as a cofactor for extracellular enzymes and regulatory proteins

Deficiencies: Acute deficiency symptoms are avoided because of the large skeletal stores. Prolonged bone resorption from chronic dietary deficiency results in osteoporosis either by inadequate accumulation of bone mass during growth or increased rate of bone loss at menopause. Dietary calcium deficiency also has been associated with increased risk of hypertension, preeclampsia, and colon cancer.

Food sources: Calcium is present in variable amounts in all the foods and water we consume, although the main sources are dairy products and vegetables. Dairy products are the most concentrated, well-absorbed sources of calcium. Few other foods are rich sources of calcium. Foods which can contribute to dietary calcium include firm tofu (chemically set with calcium), dried beans, kale, broccoli, and bok choy. Calcium from oxalate rich foods such as spinach is generally poorly absorbed. Some fortified foods are available on the market.

2000-Calorie Diet Recommendations

Shown below are the reference numbers used to compute the Daily Value percentages that appear on the Nutrition Facts labels on foods sold in the U.S. These numbers are meant to approximate the nutrients needed for the average person consuming 2000 calories per day.

Click any of the vitamin or nutrient names below to learn more about the importance of each element, and to see detailed dietary allowances for specific population groups.

***Daily Value recommendations are based on a 2000-calorie diet. Recommendations for individuals will vary depending on gender, age, weight, and other factors.