In nutrition, Calcium is essential to maintaining total body health and is the most abundant mineral in the body. Calcium is required for vascular contraction and vasodilation, muscle function, nerve transmission, intracellular signaling and hormonal secretion. 99% of the body's calcium supply is stored in the bones and teeth where it supports their structure and function.
 Food Sources
Milk, yogurt, and cheese are rich natural sources of calcium. Nondairy sources include vegetables, such as Chinese cabbage, kale, and broccoli
 Calcium Deficiency
Inadequate calcium intake causes osteopenia which if untreated can lead to osteoporosis. The risk of bone fractures also increases, especially in older individuals. Calcium deficiency can also cause rickets, though it is more commonly associated with vitamin D deficiency.
 Recommended Daily Dosage
- 0–6 months - 200 mg
- 7–12 months - 260 mg
- 1–3 years - 700 mg
- 4–8 years - 1,000 mg
- 9–18 years - 1,300 mg
- 19–50 years - 1,000 mg
- 51+ years - 1,200 mg
- Pregnant/Lactating - 1,300 mg
 Dietary Supplements
Calcium supplements are used to prevent and to treat calcium deficiencies. There are two main forms of calcium in supplements: carbonate and citrate. Calcium carbonate is more commonly available and is both inexpensive and convenient. Both the carbonate and citrate forms are similarly well absorbed, but individuals with reduced levels of stomach acid can absorb calcium citrate more easily. The body absorbs calcium carbonate most efficiently when the supplement is consumed with food. Calcium carbonate appears to cause more side effects than calcium citrate.
You probably heard "drink your milk" all the time from your parents when you were a kid, and you knew it was good for you. But now you may opt for sodas or sports drinks, and other than adding a splash to your morning Wheaties, you don't give much thought to milk.But your parents were right to make you drink milk when you were little. It's loaded with calcium, a mineral vital for building strong bones and teeth.
 Why Do I Need Calcium?
Bones grow rapidly during adolescence, and teens need enough calcium to build strong bones and fight bone loss later in life. But many don't get the recommended daily amount of calcium. In addition, people who smoke or drink soda, caffeinated beverages, or alcohol may get even less calcium because those substances interfere with the way the body absorbs and uses calcium.
Bone calcium begins to decrease in young adulthood and people gradually lose bone density as they age — particularly women. Teens, especially girls, whose diets don't provide the nutrients to build bones to their maximum potential are at greater risk of developing the bone disease osteoporosis, which increases the risk of fractures from weakened bones.
Calcium also plays an important role in muscle contraction, transmitting messages through the nerves, and the release of hormones. If people aren't getting enough calcium in their diet, the body takes calcium from the bones to ensure normal cell function, which can lead to weakened bones.
If you got enough calcium and physical activity when you were a kid and continue to do so as a teen, you'll enter your adult years with the strongest bones possible.
 How Much Do I Need and Where Can I Get It?
Teen guys and girls need 1,300 mg (milligrams) of calcium each day.
 Get it from
- Dairy products. Low-fat milk, yogurt, cheese, and cottage cheese are good sources of calcium.
- Veggies. You'll also find calcium in broccoli and dark green, leafy vegetables (especially collard and turnip greens, kale, and bok choy).
- Soy foods. Turn to calcium-fortified (or "calcium-set") tofu, soy milk, tempeh, soy yogurt, and cooked soybeans (edamame).
- Calcium-fortified foods. Look for calcium-fortified orange juice, soy or rice milk, breads, and cereal.
- Beans. You can get decent amounts of calcium from baked beans, navy beans, white beans, and others.
- Canned fish. You're in luck if you like sardines and canned salmon with bones.
 Working Calcium Into Your Diet
Looking for ways to up your dietary calcium intake? Here are some easy ones:
- Put some cheddar in your omelet.
- Pack a yogurt in your lunch.
- Add white beans to your favorite soups.
- Use whole-grain soft-taco shells or tortillas to make burritos or wraps. Fill them with eggs and cheese for breakfast; turkey, cheese, lettuce, tomato, and light dressing for lunch; and beans, salsa, taco sauce, and cheese for dinner.
- Create mini-pizzas by topping whole-wheat English muffins or bagels with pizza sauce and low-fat mozzarella or soy cheese.
- Try whole-grain crackers with low-fat cheese as an afternoon treat.
- Dig into chili with red beans and cheese.
- Eat low-fat or fat-free frozen yogurt topped with fruit.
- Create parfaits with layers of plain yogurt, fruit, and whole-grain cereal.
- You're never too old to enjoy a glass of ice-cold milk with a couple of cookies or graham crackers.
 If You're Lactose Intolerant
Teens who are lactose intolerant don't have enough of the intestinal enzyme lactase that helps digest the sugar (lactose) in dairy products, and may have gas, bloating, cramps, or diarrhea after drinking milk or eating dairy products.
Fortunately, there are low-lactose and lactose-free dairy products available, as well as lactase drops that can be added to dairy products and tablets that can be taken to make dairy products tolerable. Hard, aged cheeses (such as cheddar) are also lower in lactose, and yogurts that contain active cultures are easier to digest and much less likely to cause lactose problems.
 If You're a Vegetarian
It can be a challenge to get enough calcium in a vegetarian diet that does not include dairy, but you can enjoy good sources of calcium such as dark green, leafy vegetables, broccoli, chickpeas, and calcium-fortified products, including orange juice, soy and rice drinks, and cereals.
 Other Considerations for Building Bones
- Vitamin D is essential for calcium absorption, so it's important to get enough of this nutrient too. Made by the body when the skin is exposed to sunlight, vitamin D is also found in fortified dairy and other products, fish, and egg yolks.
- Exercise is very important to bone health. Weight-bearing exercises — such as jumping rope, jogging, and walking — can help develop and maintain strong bones. In fact, current scientific evidence suggests that for teens, exercise may be even more strongly linked to better bone health than calcium intake.
Although it's best to get the calcium you need through a calcium-rich diet, sometimes it may not be possible. Discuss calcium supplements with your doctor if you're concerned that you're not getting enough.
 The uses of calcium
- Calcium is an important nutrient that we need in our bodies. It has a number of important functions. It helps develop strong bones and teeth and is involved in blood clotting and muscle contractions.
- Most of the calcium is stored in our body's bones and teeth. When the calcium levels in the body drop below normal, calcium is taken from the bones and teeth resulting in a severe calcium loss. Low calcium leads to bone fractures and in many older people osteoporosis or porous bones.
- Calcium is one of the most plentiful minerals in the human body. The body needs Vitamin D to absorb calcium properly. Severe calcium loss in children can cause rickets. In adults it can cause muscle spasms, insomnia and irritability.
- The use of calcium can reduce high blood pressure, keep your heart regular, prevent gum disease, prevent cancer of the colon and rectum and help blood to clot. Most American do not get enough calcium from foods that they eat. Believe it or not, it's the fifth most abundant element on earth.
 Requirements for Children
What are some of the requirements for the use of calcium for children?
- Toddlers ages one to three require about 500 milligrams or two glasses of milk daily.
- Children four to eight-years-old require about 800 milligrams or three glasses of milk daily.
- Older children from the age of nine up to 18 require more calcium. They should consume about 1300 milligrams of calcium or four glasses of milk daily.
Calcium is lost in cooking so to retain as much calcium as possible, cook foods in a minimal amount of water. Another tip is to cook foods with calcium for as short a period of time as possible.
Make it even easier to meet your calcium requirements by taking calcium supplements with meals.