hough the role of calcium in building strong bones and teeth is well-known, not many of us are aware of the importance of calcium in maintaining other vital body processes such as blood clotting, transmission of nerve signals, supporting normal heartbeat, assisting in muscle contraction and production of hormones and other chemicals. Given its multiple uses, among the different minerals found in the human body concentration of calcium is, therefore, the highest. Almost 99% of the body’s calcium is present in the bones, and the remaining 1% is found in the body tissues, nerve cells, blood, and other body fluids. 
Consumption of calcium-rich foods helps in sustaining the healthy calcium reserve in your body. A calcium deficient diet tends to weaken the bones and affects your general health by impairing the important body functions. To avert calcium deficiency, add calcium-rich foods to your diet that could meet your body’s daily calcium requirement.
How Much Calcium You Need Daily
The amount of calcium an individual should consume daily depends upon age and gender. The Dietary Reference Intake developed by America’s Institute of Medicine’s Food and Nutrition Board is followed all over the globe in determining the appropriate amount of calcium that an individual should try to consume daily. When the recommended calcium intake is based on evidence provided by scientific research, the term Recommended Dietary Allowance (RDA) is used. The term Adequate Intake (AI) is used when the recommended calcium intake is not supported by adequate scientific research.
According to the dietary guidelines, AI for calcium for babies up to six months of age is 200 mg per day and for babies from 7 to 12 months, 260 mg per day is considered as adequate intake. The RDA for children from 1 to 3 years of age is 700 mg per day, from 4 to 8 years of age is 1000 mg per day and from 9 to 18 years of age, it is 1300 mg per day.
In adult men and women from 19 to 50 years of age, the RDA for calcium is 1000 mg per day. Men can continue with the same daily calcium intake up to the age of 70. After 70, their RDA for calcium increases to 1200 mg per day. Women after the age of 50 are required to increase their daily calcium intake to 1200 mg. The RDA for calcium during pregnancy and breastfeeding is the same as the RDA for the specific age group.
Though the RDA for calcium is considered adequate for meeting the body’s nutritional need in 97% to 98% healthy people, in specific situations, a higher amount of calcium can be consumed. The maximum amount of calcium intake considered safe for children is between 2500 to 3000 mg per day. Adults should limit their maximum calcium intake to 2000 to 2500 mg per day. 
Foods High in Calcium
However, studies have revealed that the average dietary calcium intake in most countries is below the recommended amount. The average dietary calcium intake in most of the Asian countries is found to be lower than 500 mg per day. In countries of Africa and South America, the average dietary calcium intake is between 400 and 700 mg per day. Only in the countries of Northern Europe, the average calcium intake is above 1000 mg per day.  However, calcium deficiency can be easily averted by increasing the consumption of foods in which calcium is found in large quantities.
1. Plain Low Fat Yogurt
An 8-ounce serving of low-fat plain yogurt contains 415 mg of calcium, which is equivalent to 42% of the Daily Value (DV) for calcium.
Cheese is an excellent source of calcium. However, the exact amount depends upon the type of cheese. 1 ½ ounce of part-skim mozzarella contains 333 mg of calcium. The same amount of cheddar cheese provides 307 mg of calcium. Your body will get about 138 mg of calcium from one cup of cottage cheese with 1% milk fat.
The calcium content in milk is inversely associated with fat content. The calcium level is therefore found to be highest in nonfat milk and lowest in whole milk. An 8-ounce serving of nonfat milk contains 299 mg of calcium, the same amount of milk with 2% milk fat provides 293 mg of calcium and an 8-ounce serving of whole milk with 3.25% fat contains 276 mg calcium. Eight ounces of low-fat buttermilk provides 284 mg of calcium.
By consuming 3 ounces of canned sardines with bones, you will get about 325 mg of calcium.
The concentration of calcium is higher in soymilk fortified with calcium. Eight ounces of calcium-fortified soymilk provides 299 mg of calcium which is the same as the amount of calcium found in nonfat milk.
Tofu prepared by coagulating soymilk with calcium sulfate is a good source of calcium. Half a cup of firm tofu contains 253 mg of calcium and the same amount of soft tofu contains 138 mg of calcium. However, tofu made with salts other than calcium sulfate is a poor source of calcium.
7. Turnip Greens
Among vegetables, green leafy vegetables are good sources of calcium. You will get 99 mg of calcium from half a cup of fresh boiled turnip greens.
A cup of freshly cooked kale contains 94 mg of calcium, which is equivalent to 9% of the Daily Value for calcium. From an 8-ounce serving of frozen kale, you will get about 200 mg of calcium.
9. Collard Greens
An 8 oz serving of collard greens provides 360 mg of calcium.
Half a cup of raw broccoli contains 21 mg of calcium. Eight ounces of freshly cooked broccoli provides 60 mg.
11. Broccoli Rabe
Rapini, commonly known as broccoli rabe, is another good source of calcium. Eight ounces of the vegetable contains 200 mg of calcium.
12. Fortified Juice and Cereal
You can get a significant amount of calcium by consuming calcium-fortified orange juice or ready-to-eat cereal. Six ounces of calcium-fortified orange juice contains 261 mg calcium. A cup of calcium-fortified ready-to-eat cereal can provide 100 mg to 1000 mg of calcium.  
Health Benefits of Calcium-Rich Foods
The Following are the amazing health benefits of Calcium-Rich Foods:
1. Builds Strong Bones
Calcium is the major constituent of the bones. Our bones go through a continuous remodeling process that involves removal of a small amount of calcium from the bones, which is then replaced with new calcium. The bone weakens when the amount of calcium lost from the bones exceeds the amount of new calcium that enters the bone. The bones maintain their own calcium reserve that enables them to sustain the normal remodeling process. Increased intake of foods rich in calcium is therefore encouraged during childhood and adolescence when the calcium reserve increases in the bones. However, the calcium reserve reaches its maximum level at the end of adolescence. After the teen years, the dietary goal of an individual should be to maintain the existing calcium reserve. 
2. Supports Weight Loss
Recent studies suggest that diets high in calcium could help in reducing obesity risk. According to a study, middle-aged women with the highest dairy intake are able to maintain their normal body weight whereas women who consume minimal dairy product are susceptible to weight gain. However, increased dairy intake could only help you in managing healthy body weight only when you control your total calorie intake. Calcium stored in the fat cells regulates metabolism and storage of fats. A higher level of calcium in fat cells helps speed up the burning of fats. 
3. Helps Reduce High Blood Pressure
A high calcium diet is believed to be effective in lowering the high blood pressure level. A study had found an association between low intake of dairy products, calcium and vitamin D and a higher risk of hypertension in middle-aged and older women.  In another clinical study, researchers found that increased calcium intake was more effective in reducing the diastolic blood pressure level. 
4. Helps Lower Cholesterol Level
Some studies suggest that calcium can help in decreasing the total cholesterol level in some individuals. A study revealed that in hypertensive individuals, calcium supplementation did not cause any significant change in the total cholesterol level. However, in mildly hyperlipidemic individuals with normal blood pressure significant reduction in total cholesterol level following calcium supplementation was observed. 
5. Helps Reduce Risk of Pre-Eclampsia
Pre-eclampsia is a hypertensive disorder that affects pregnant women. It is one of the major causes of preterm birth and maternal mortality. Usually, the blood pressure level tends to fall during early pregnancy and it gradually increases during the last stage of pregnancy. Risk of pre-eclampsia is higher in pregnant women who are obese, diabetic or pregnant with twins. A calcium deficient diet is also a possible cause of pre-eclampsia. Babies born to women with this hypertensive disorder are susceptible to respiratory and long-term neurological disorders. The World Health Organization (WHO) has recommended daily supplementation with 1.5 g to 2 g of calcium for pregnant women who do not get sufficient calcium from the diet. 
6. Helps Decrease Diabetes Risk
It is believed that altered calcium and vitamin D homeostasis is associated with the development of type 2 diabetes. Observational studies have shown the people with type 2 diabetes usually have lower levels of calcium and vitamin D intake. Evidence from clinical trials suggests that supplementation with calcium and vitamin D can help in lowering diabetes risk in individuals who are susceptible to the condition due to a higher rate of glucose intolerance. 
7. May Help Reduce Risk of Certain Cancers
Some studies have found an association between higher calcium intake and lower risk of certain cancers. Calcium intake is believed to reduce the risk of colorectal cancer. Studies suggest that people who take more than 700 mg of calcium daily have 35% to 45% less risk of developing cancer in the lower part of the colon than individuals who take no more than 500 mg calcium per day. Risk of developing colorectal cancer appears to be 28% lower among people whose daily calcium intake is from 800 mg to 1000 mg than those who consume 400 to 500 mg calcium per day. Calcium seems to help in reducing recurrence of colorectal polyps or adenomas that are known to be precursors of most colorectal cancers.
It is believed that in the gastrointestinal tract calcium combines with fatty acids and bile acids and forms complex compounds called calcium soaps. Calcium soaps are insoluble. They help in protecting the cells in the colon lining from the harmful activities of the acids and their metabolites. Calcium soaps are also known to repair the damaged tissue by inducing growth of new cells. Calcium is also believed to play a role in improving signaling within the cells that promote the death of the cancer cells.
In healthy postmenopausal women, calcium supplementation along with vitamin D appeared to reduce the risk of all types of cancers by 60%. Increased intake of low-fat milk and dairy appears to reduce the risk of developing ovarian cancer. 
Symptoms of Calcium Deficiency
The symptoms of calcium deficiency are both acute and chronic. Short-term deficiency is known to cause excessive sweating during heavy exercises. Calcium deficiency alters neuromuscular function that leads to muscle cramps. However, calcium is not the only mineral associated with muscle cramps. Depletions of potassium, magnesium and sodium reserves in the muscle are the major causes of cramps. Muscle cramps caused by loss of calcium and other minerals through sweat can be relieved by drinking electrolyte beverages.
Prolonged calcium deficiency causes bone loss or osteoporosis. This chronic symptom of calcium deficiency is usually observed after the age of 60. However, in a small number of cases, osteoporosis occurs in young adults due to athletic amenorrhea. 
Risks of Excessive Calcium Intake
The tolerable higher limit of daily calcium intake is 2500 mg for children from 1 to 8 years of age, 3000 mg for children aged 9 years and above and teenagers, 2500 mg for adults up to 50 years of age and 2000 mg for adults above 50 years of age.
Excess calcium intake elevates the serum calcium level, leading to hypercalcemia. It causes calcification of vascular and soft tissues, renal insufficiency, high level of calcium in the urine and kidney stones. Too much calcium intake is one of the major causes of constipation. It impairs iron and zinc absorption. In some cases, the risk of developing prostate cancer may increase because of excess calcium intake. However, the adverse effects are primarily associated with calcium supplement intake. Calcium overload from consumption of calcium-rich foods is rare.  Therefore, you can devour foods high in calcium without worrying about harmful side effects.