Calcium is one of the most necessary minerals that the body needs in all age stages (children, adults, or elderly and males or females). Calcium has a role in many vital functions that the body should perform to grow, develop, and maintain health. Calcium is mainly essential for bone and teeth health; it contributes to bone development in children and keeps the bone density in adults, which protects against osteoporosis. Not only bone and teeth, but also calcium is essential for muscles, nervous system, immune system, and cardiovascular system. Calcium is a necessary element in the muscle contraction process for cardiac, smooth, and skeletal muscles. When the nervous system instructs a muscle to contract, calcium enters inside the muscle cells and causes contraction. After contraction, calcium exists from the muscle cell, and relaxation occurs. As the muscles need the calcium to contract, the nervous system can’t conduct the nerve signals to the muscles without calcium. The nervous system needs enough level of calcium to conduct the signals between the brain and the rest of the body. The cardiovascular system also needs calcium in a lot of its vital functions. As we said, calcium is necessary for muscle contraction, and this includes the heart muscle; thus, calcium is essential for the heart to beat at normal force and rate. Also, adequate calcium lowers the risk of hypertension (especially for pregnant females and young people) because it relaxes the muscles in the wall of blood vessels. Blood coagulation is another vital process that calcium plays an essential role in it. This process involves many chemicals, and calcium is one of them. Calcium activates platelets and some coagulation factors. Calcium also represents a cofactor for many enzymes that contribute to vital biochemical processes in our cells, and these enzymes can’t function without it.
All of the previous vital functions require us to pay attention to keep the calcium level in blood within the healthy range (9:11 mg/dl). But, your body can’t produce calcium; thus, you will depend mainly on your diet to get what your body needs from calcium. Calcium presents in many foods, such as dairy products (milk, cheese, and yogurt), sardines, dark green vegetables (kale and broccoli), and orange juices. Calcium also is available as food supplements, such as calcium carbonate and calcium citrates. Some people may need calcium supplements if they don’t get an adequate amount from their diets, such as people who suffer from lactose intolerance and vegans.
Calcium in the body concentrates in the bone (99% of the body calcium). The bone acts as a calcium store. When the blood calcium becomes low, the body moves calcium from the bone to the blood by parathormone hormone, and the opposite occurs by calcitonin hormone.
You can’t benefit from your dietary calcium unless you have enough vitamin-D because it is necessary for calcium absorption. Your skin can synthesize vitamin-D by adequate sun exposure. Also, you can get vitamin-D from some foods, such as egg yolks, salmon, and mushrooms, or food supplements. Calcium supplements may lead to side effects, such as constipation, abdominal gases, itching, and drowsiness; thus, you should discuss taking it with your doctor to see if you need it or no.
The recommended daily intake of calcium depends on your age, as follow:
- Children up to twelve months need about 200:250mg daily.
- Children from one to three years need about 700mg daily, and from four to eight years need about 1000mg daily.
- Children from nine to thirteen years and teens from fourteen to nineteen years need about 1300mg per day.
- Adults, up to fifty years, need about 1000mg daily, either males or females.
- From fifty to seventy years, male needs about 100mg and female about 1200mg. After seventy years, both of them will need 1200mg daily.
- Pregnant and breastfeeding females will need about 1000mg daily for teens or 1300mg for adults.
As with all nutrients that you need, either excess or deficient intake can lead to health problems. Low calcium may predispose to osteopenia (low bone density), osteoporosis, fractures, fatigue, loose teeth, brittle nails, arrhythmias, and tetany. Excess calcium may lead to constipation, renal stones, abdominal pain, arrhythmias, dry skin, and itching. These manifestations mainly occur after a long period of disturbed calcium intake and with people who have other health problems or take medications.
To take enough amount of calcium from the diet, you should be aware of the foods that rich in it to include it in your diet, which may eliminate the need for food supplements and protects you from problems of low or excess calcium.
» Now, we will focus on foods rich in calcium «
1. Cheese
Cheese is a dairy product that is popular worldwide and has a high nutritional value. Cheese is a rich source of calcium and other essential minerals and vitamins. We have various types of cheese that supply calcium in varying quantities. Parmesan cheese provides 91% of the recommended daily intake (about 1185mg) from 100 grams. Other types of cheese contain calcium, such as:
- Swiss cheese: one ounce (28 grams) provides 19% of the recommended daily intake of calcium.
- Feta cheese: four ounces contain 140mg of calcium.
- American cheese: one-ounce supplies 195mgof calcium.
Other types have various amounts of calcium. Besides its content of calcium, the calcium of the cheese and other dairy products are easily absorbable than calcium of plant sources. Also, cheese may be suitable for some people with lactose intolerance because aged and hard cheese is low in lactose.
Cheese doesn’t provide calcium only, but also, it is rich in proteins and vitamins (A and B). It lowers the risk of heart disease, stroke, diabetes, and metabolic syndrome (obesity, high blood pressure, and raised lipids and glucose).
2. Yogurt
Yogurt is a healthy dairy product of excellent nutritional value. It is a rich source of calcium, and it is also high in proteins, potassium, phosphorus, magnesium, and zinc. We can get 30% of the recommended daily intake from one cup (or 245 grams) of plain yogurt. Low-fat yogurt is higher in calcium; it supplies 45% of the recommended daily intake from one cup. Greek yogurt contains lower calcium, but it is higher in protein (it adds extra protein to your diet).
Besides this high nutritional value, yogurt improves the overall quality of health; it lowers the risk of hypertension, heart disease, and diabetes. Yogurt improves the health of the digestive system because it is a fermented dairy product, which promotes the growth of beneficial intestinal bacteria (intestinal flora).
3. Milk
Milk is a rich, cheap, and good source of calcium. Either cow or goat milk, both are rich in calcium. One cup of cow milk provides 257mg (whole milk) or 350mg (non-fat milk). Goat milk gives 237mg calcium from one cup. As with calcium, milk is also a rich source of protein and vitamins (A and D). Remember that calcium from dairy products, such as milk, cheese, and yogurt, is easily absorbable than calcium from plant sources.
Dairy products are the richest source of calcium, but dairy foods may be unsuitable for some people, such as lactose intolerants. They don’t have to worry because we have other non-dairy foods that high in calcium.
4. Seeds
Seeds are tiny foods, but their nutritional value makes them small powerhouses. The Seeds rich in calcium includes chia seeds, poppy, sesame, and celery. We can get 126mg calcium (or about13% of the recommended daily intake) from one tablespoon or 9 grams of poppy seeds. We don’t get calcium only from the seeds, but also some of them are rich in protein, good fats, and minerals. Chia seeds are rich in omega-3-fatty acids. From sesame seeds, we can get 9% of the recommended daily intake from one tablespoon in addition to other vital minerals, such as iron, copper, and manganese.
5. Beans and lentils
Beans and lentils are highly nutritious foods that contain suitable amounts of calcium. We can get 24% of the recommended daily intake of calcium from one cup of cooked winged beans (around 170 grams) and 14% from one cup of cooked white beans. Other types of beans and lentils contain lower amounts of calcium.
Beans and lentils are also rich in fibers, protein, folic acid, and other minerals, such as iron, potassium, zinc, and magnesium.
Scientific research found a beneficial effect for beans and lentils on the level of bad cholesterol (LDL) and the risk of Diabetes Miletus.
6. Almonds
Almonds are nuts that are rich in calcium, protein, good fats, fibers, vitamin-E, and other minerals (manganese and magnesium). We can get 8% of the recommended daily intake from one-ounce (or about 22 nuts). Also, one-ounce provides 3 grams of fiber. Nuts lower the risk of obesity, hypertension, diabetes, and heart diseases.
7. Sardines and Salmon
These tiny and delicious fish are of high nutritional value and contain a lot of valuable elements. These fish are rich in calcium; we can get 35% of the recommended daily intake from 4 ounces (or about 100 grams) of sardines and 21% of the RDI of calcium from 3 ounces (or about 85 grams) of canned Salmon.
Sardines also rich in vitamin-D, Vitamin-B12, selenium, iron, copper, phosphorus, and magnesium. Sardines and canned Salmon also contains proteins of high biological value and omega-3-fatty acids, which are useful for your skin, heart, and brain.
8. Dark leafy vegetables
Dark leafy vegetables contain a variety of useful minerals and have a lot of health benefits. Some of these vegetables are rich in calcium, such as spinach, kale, and collard greens. We can get 25% of the recommended daily intake (or about 266mg) of calcium from one cup (or 190 grams) of collard greens and 20% (or about 180mg) from one cup of kale. Spinach gives 245mg calcium (or about 19% of the RDI) from one cooked cup, but it is also high in oxalates, which binds to calcium and impairs its utilization by the body. Other green vegetables contain calcium, such as broccoli, cabbage, bok choy, and turnip greens.
Dark leafy greens are also a rich source of fiber, vitamins (A, C, E, and K), minerals (potassium and manganese), folic acid, and antioxidants (lutein and B-carotene). Consumption of many leafy greens in the diet reduces the risk of hypertension, heart diseases, obesity, and problems.
9. Fortified foods
Fortified foods are a great way to obtain the majority of the required intake of calcium. We can get about 100% of the recommended daily intake from some types of fortified cereals. Other foods fortified with calcium include flour and cornmeal. These foods are high in calcium, but your body can’t absorb all of this calcium at once; thus, you should distribute your intake all over the day.
10. Fortified drinks
Fortified drinks also represent a rich source of calcium. The fortified drink is an excellent choice for those who don’t drink milk. From one cup (or 237ml), we can get 30% of the recommended daily intake of calcium. Other types of fortified milk, such as nuts and see-based milk, contain higher amounts of calcium. Not only milk, other fortified drinks, such as orange juice, can give 50% of the recommended daily intake of calcium from one cup.
11. Figs
Figs are dried fruit that contains calcium more than other dried fruits. One-ounce (28 grams) provides 5% of the recommended daily intake of calcium. Figs also are rich in antioxidants, fiber, vitamin-K, and potassium.
12. Edamame and tofu
Edamame and tofu contain high amounts of calcium. One cup (about 155 grams) of edamame provides 10% of the recommended daily intake of calcium and 100% of the required daily consumption of folic acid. It is also a good source of protein.
Tofu (prepared with calcium) gives 86% of the required daily intake of calcium from half a cup.
13. Whey protein
Whey protein is rich in calcium; we can get 200mg calcium (or 20% of the recommended daily intake) from a one-ounce (28 grams) scoop of whey protein. Whey protein is also rich in protein and easily digested amino acids. Whey protein also plays a role in weight loss and improves blood glucose control.
Finally, calcium is essential for all people, in all age groups, both sexes, and patients and healthy individuals. We need calcium, but also, we should take it with suitable amounts to avoid hyper and hypocalcemia; thus, we should be aware of the recommended daily intake that matches our age, sex, and health status.