Calcium, the most common mineral in the body, plays an essential role in blood clotting, muscle contraction, nerve impulse transmission, and bone and tooth formation.
Studies indicate that calcium plays a role in blood vessels contraction and dilation which effects blood pressure. Also, the role of calcium in helping with weight control appears is promising.
A constant level of calcium is maintained in body fluid and tissues so that these vital body processes function efficiently. More than 99 percent of body calcium is stored in the bones and teeth; the remaining 1 percent is found in blood, muscle and the fluid between cells.
Calcium is lost from the body every day in urine and feces, and trace amounts are lost in sweat, shedding skin, hair and nails. The lost calcium is normally replaced by calcium from food. If your diet does not contain enough calcium or if you don’t absorb enough calcium from your food or supplements to replace the lost calcium, the body breaks down bone to get the calcium it needs.
To absorb enough calcium, your body also needs vitamin D. Your skin can make vitamin D when it is exposed to direct sunlight. Other sources of vitamin D are fatty fish, eggs, liver, butter, fortified foods such as milk and multivitamins. People at risk for having too little vitamin D are elderly adults, those in institutions and some people with chronic neurological or gastrointestinal diseases. People living north of the 45th parallel may need supplements in the winter to maintain adequate vitamin D levels.
According to the U.S. Department of Agriculture (USDA), the amount of calcium you need each day depends on your age. Children ages 1 to 3 years need 500 mg a day; children 4 to 8 years old need 800 mg a day; and children 9 to 18 need 1,300 mg a day. Adults ages 19 to 50 should get 1,000 mg a day; those older than 50 need 1,200 mg a day. The best way to get calcium is from food. The USDA recommends a minimum of three cups of nonfat or low-fat vitamin D-fortified milk or equivalent milk products each day.
A consistent level of calcium in the body’s fluids and tissues is needed for muscle contraction, blood vessel contraction and expansion, the secretion of hormones and enzymes, and transmission of messages through the nervous system. Adequate intake of calcium and vitamin D may help prevent some conditions. Adequate calcium throughout a person’s lifetime can help build and maintain adequate bone mass, helping to prevent osteoporosis.
Calcium from dairy products in combination with a diet high in fruits, vegetables and low-fat dairy can help keep blood pressure in check and help prevent the absorption of dietary fat; this helps decrease blood cholesterol.
For people on weight-loss diets, three or more servings of dairy products a day may accelerate weight loss and may help prevent weight gain.
In a limited number of studies, consuming milk products has been related to a decreased risk for insulin resistance syndrome, otherwise known as syndrome X or the metabolic syndrome. This syndrome leads to an increased risk for type 2 diabetes and cardiovascular disease.
But calcium may need other nutrients to help achieve these health benefits. In most studies that looked at calcium and prevention of disease, milk was the major source of calcium. In addition to calcium, milk contains potassium, magnesium, vitamin D and vitamin A. The extent to which these other components work with calcium to prevent conditions is not known.
To help consume enough calcium each day, start with food and drink. . Calcium in food is better absorbed by the body than calcium in a supplement. The additional compounds in dairy products act with calcium to promote its benefits. Strive to consume at least three calcium-rich foods daily such as low-fat or nonfat yogurt, 1 percent or skim milk, low-fat ice cream, calcium-fortified orange or grapefruit juice, low-fat cheese and low-fat cottage cheese.
Also, look for foods with added calcium such as rice and some breakfast cereals.
If you're lactose intolerant, don't avoid dairy products. Lactose intolerance is easy to manage.
Aged cheese and yogurt tend to be more easily digested by people who are lactose intolerant; eat them in small quantities along with other food. Foods made with active or "live" cultures, like yogurt or buttermilk, are also easier to digest because their "friendly" bacteria help digest lactose. Other options include lactose-free milk, lactose-free cottage cheese and nondairy sources of calcium, such as calcium-fortified soy milk, tofu, baked beans, almonds, broccoli, kale and other dark green leafy vegetables, and canned salmon and sardines with the bones. For canned fish, you need to eat the bones to get the calcium.
Vitamin D is necessary for your body to absorb the calcium you get from foods or supplements. You can get vitamin D from foods fortified with it or by spending 10 to 15 minutes in the sun at least two times per week. Adults 19 to 50 need at least 200 IU of vitamin D a day; those 51 and older need 600 to 800 IU a day.
Although lots of foods contain calcium, for the most part, people are still not meeting the recommended intake.
If you're not consuming at least three calcium-rich foods per day, consider taking a calcium supplement. If you use a supplement, however, don't depend on it to meet your calcium needs.
A good bet: Take a 500 mg calcium supplement each day and try to get the remaining 500 to 700 mg of calcium from food.
Calcium supplements come in different forms, such as calcium carbonate and calcium citrate. Some have vitamin D added to them for extra benefit.
Research indicates that calcium citrate is absorbed better than other supplements, such as calcium carbonate. But to get the enhance a calcium supplement's absorption, take it with a citrus based food - like orange juice.
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