But during your preteen and teenage years, you can reduce your risk of fractured bones later in life with calcium-rich foods and physical activity.

Bone Behavior

Your body’s 206 living bones continually undergo a buildup, breakdown process called remodeling.

The body starts to form most of its bone mass before puberty, the beginning of sexual development, building 75 to 85 percent of the skeleton during adolescence. Women reach their peak bone mass by around age 25 to 30, while men build bone until about age 30 to 35. The amount of peak bone mass you reach depends largely on your genes. Then gradually, with age, the breakdown outpaces the buildup, and in late middle age bone density lessens when needed calcium is withdrawn from bone for such tasks as blood clotting and muscle contractions, including beating by the heart.

“You can’t do anything about the genes you’re dealt,” says Mona Calvo, Ph.D., a calcium expert for the Food and Drug Administration. “As a teenager, though, you can make the most of things you do control that can build your bones and help reduce the risk of fractures when you are older.”

Supporting the skeleton with healthful habits now so it can support you later in life is especially important if you have an increased risk of osteoporosis–for example, if you’re female or have a thin, small-boned frame. These habits are proper diet, exercise, and avoiding bone risks–lifestyle choices that are bad for bone, like smoking.

Eat Your Way to Strong Bones

The main mineral in bones is calcium, one of whose functions is to add strength and stiffness to bones, which they need to support the body. To lengthen long bones during growth, the body builds a scaffold of protein and fills this in with calcium-rich mineral. From the time you’re 11 until you’re 24, you need about 1,200 milligrams (mg) of calcium each day.

Adolescent bodies are tailor-made to “bone up” on calcium. Calvo says that with the start of puberty, “your body is at a higher capacity to absorb and retain calcium.”

Bone also needs vitamin D, to move calcium from the intestine to the bloodstream and into bone. You can get vitamin D from short, normal day-to-day exposure of your arms and legs to sun and from foods fortified with the vitamin. Also needed are vitamin A, vitamin C, magnesium and zinc, as well as protein for the growing bone scaffold.

Mother Nature provides many foods with these nutrients. One stands out, however, as “almost a perfect package,” according to Calvo. “Milk is rich in calcium and high-quality protein. Nearly all U.S. milk has vitamins D and A added. And it has magnesium and zinc.”

Still, as excellent as milk is for bones, it and other dairy products are not the only foods that contain calcium. All groups in the Food Guide Pyramid, in fact, offer calcium sources–from the pyramid’s grain-based foods that you need the most of, to the produce and high-protein groups in the middle, and even to the fats and sweets “use sparingly” group at the top. The importance of choosing calcium sources from the different food groups is that each group offers its unique package of other nutrients as well.

To learn how much calcium is in a food, you can read the food label’s Nutrition Facts panel. Look for the “percent Daily Value” (%DV) set by FDA for calcium. The calcium DV is 1,000 mg. But if you are 11 to 24 years old, your growing bones need more–the recommended 1,200 mg. So, each day’s calcium %DVs in the foods you eat should add up to 120 percent.

Because many foods are now fortified with calcium, your investigation of labels may turn up surprising sources. To identify foods with at least 10%DV of calcium per serving, FDA allows these terms on their labels:

• 20%DV or more: “High in Calcium,” “Rich in Calcium,” “Excellent Source of Calcium”
• 10% to 19%DV: “Contains Calcium,” “Provides Calcium,” “Good Source of Calcium”
• 10%DV calcium or more added: “Calcium-Enriched,” “Calcium-Fortified,” “More Calcium.”

An easy daily plan is to drink a calcium source at every meal and eat one calcium food as a snack, says Ruth Welch, a registered dietitian with FDA.

If the lactose sugar in dairy products causes problems like gas, bloating or diarrhea, try lactose-reduced or lactose-free milk. When fortified, these products can have up to 50%DV for calcium in one serving. Also available are lactase drops and tablets, which can help you digest dairy products like ice milk, yogurt, and cheese.

Get Enough Weight-Bearing Exercise

Growing bone is especially sensitive to the impact of weight and pull of muscle during exercise, and responds by building stronger, denser bones. That’s why it’s especially important when you’re growing a lot to be physically active on a regular basis.

And as far as bone is concerned, Calvo says impact activity like jumping up and down appears to be the best. “But the important thing is to get off the couch and get moving at some activity. It really is a matter of ‘Use it now, or lose it later’.”

Such activities include sports and exercise, including football, basketball, baseball, jogging, dancing, jumping rope, inline skating, skateboarding, bicycling, ballet, hiking, skiing, karate, swimming, rowing a canoe, bowling, and weight-training. And when your parents make you mow the lawn, rake leaves, or wash and wax the car, they’re doing your muscles and bones a favor.

FDA’s Welch adds, “Day-to-day activities that start in the teen years, like walking the dog or using stairs instead of elevators, can become life-long habits for healthy bones.”

Avoid Bone Risks

Some habits in the teenage years can steal calcium from your bones or increase the need for it, weakening the skeleton for life.

Skipping meals is risky for bone, Welch says. In our three-meal-a-day society, skipping a meal may reduce by a third your chance of getting your 120%DV for calcium–simply by eliminating one occasion to eat.

Replacing milk with nondairy drinks like soda pop or fruit-flavored teas or drinks is another eating habit that prevents bones from getting the calcium and other nutrients they need.

In a survey comparing 1994 daily beverage intakes with those in the late 1970s, the U.S. Department of Agriculture found a switch from milk to other drinks among young people:

• Milk drinkers among teenagers dropped from three-fourths to little more than half.
• Two to three times more children and teenagers drank non-citrus fruit juices.
• Teenage boys nearly tripled their intake of soft drinks, three-fourths of them drinking about 34 ounces; two-thirds of teenage girls drank 23 ounces.

Alcohol abuse and cigarette smoking can hurt bone. Calvo says, “Alcohol abuse can cause loss of calcium, magnesium and zinc in the urine. Many who abuse alcohol also have poor diets and malnourished, weaker bones.” Cigarette smoke is also toxic to bone and can influence how much exercise you get because it affects your stamina, she says.

Eating disorders can weaken bone. The repeated vomiting in bulimia and extreme dieting in the appetite disorder anorexia can upset the body’s balance of calcium and important hormones likebone-protective estrogen, decreasing bone density. And extreme exercising by young women with or without eating disorders can postpone or stop menstruation, when blood levels of estrogen are reduced.

Small Changes for Big Benefits

As a disorder of aging, osteoporosis may seem far away for worry when you’re 15. But, small changes today for better bones tomorrow may be more important than you might guess.

Laura Bacharach, M.D., of Stanford University, wrote in Nutrition & the M.D. last year that adolescents who make “even a 5 percent gain in bone mass can reduce the risk of osteoporosis by 40 percent.” And this is in addition to “immediate benefits of feeling stronger and more fit now with these changes!”

“Calcium! Do You Get It?”

Unlike boys, growing girls typically have low calcium intakes. Concerned about the low intakes, the Food and Drug Administration recently developed a pilot education program, funded by the agency’s Office of Women’s Health, just for girls ages 11 to 14. “Calcium! Do You Get It?” encourages girls to get enough calcium and exercise for healthy bones and to carry these healthy behaviors throughout life. This article includes much of the information in the program.

Girls Don’t Get Enough Calcium

Between the ages 11 and 24, people need at least 1,200 milligrams (mg) of calcium every day. A 1995 survey by the U.S. Department of Agriculture, however, found that girls and young women 12 to 19 got only 777 mg of the mineral daily, overall. Intake by boys and young men in the same age group was 1,176 mg daily.

Daily calcium intake by preteen girls was far short of the recommended level also in 1990-1992 and fell with age, wrote Ann Albertson, M.S., R.D., and others recently in the Journal of Adolescent Health. Calcium consumption was only 781 mg at ages 11 to 12, 751 at ages 13 to 14, and a mere 602 mg–barely half what it should be–at ages 15 to 18.

Why is calcium intake in girls and young women so low?

USDA’s Agricultural Economic Report No. 746 gives some clues. Compared with other children, female adolescents:

• drink the least amount of fluid milk
• have the highest tendency to skip morning meals, which offer the most calcium because of milk and cereals
• have the highest share of calories from fast-food places, which have a calcium density much lower than foods prepared at home, schools or restaurants.

Panic Disorder

Panic disorder includes repeated episodes of intense fear that strike often and without warning. Physical symptoms include:

• Chest pain
• Heart palpitations
• Shortness of breath
• Dizziness
• Abdominal distress
• Feelings of unreality
• Fear of dying.

Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is characterized by repeated, unwanted thoughts or compulsive behaviors that seem impossible to stop or control.

Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) consists of persistent symptoms that occur after experiencing or witnessing a traumatic event, such as:

• Rape or other criminal assault
• War
• Child abuse
• Natural or human-caused disasters
• Crashes.

Nightmares; flashbacks; numbing of emotions; depression; and feeling angry, irritable, or distracted are common. It is also common for people with PTSD to be easily startled. Family members of victims can also develop this disorder.

Phobias

The three types of phobias are social phobia, specific phobias and agoraphobia. People with social phobia have an overwhelming and disabling fear of scrutiny, embarrassment, or humiliation in social situations, which leads to avoidance of many potentially pleasurable and meaningful activities. People with a specific phobia experience extreme, disabling, and irrational fear of something that poses little or no actual danger. The fear leads to avoidance of objects or situations, and can cause people to limit their lives unnecessarily. Agoraphobia involves intense fear and avoidance of any place or situation where escape might be difficult or help unavailable in the event of developing sudden panic-like symptoms. Agoraphobia rarely occurs in the absence of panic disorder.

Generalized Anxiety Disorder

Generalized anxiety disorder is defined as constant, exaggerated worrisome thoughts and tension about everyday, routine life events and activities. These thoughts must last at least six months to be classified as generalized anxiety disorder. People with this condition almost always anticipate the worst, even though there is little reason to expect it. These feelings are accompanied by physical symptoms, such as:

• Fatigue
• Trembling
• Muscle tension
• Headache
• Nausea.

What Causes It?

Scientists aren’t quite sure why some people get anxiety disorders. Different people exposed to the same situation can react in very different ways. Part of this difference may be in the genes they have inherited.

Anxiety disorders run in families, so if a parent has an anxiety disorder, the children have a higher chance of developing one of these conditions. This may be due to the genes they’ve inherited, but the environment a child is raised in may be important, too. Ultimately, it’s probably an interaction between a person’s genetic predisposition and environment.

Scientists have recently been gaining insights into the development of anxiety disorders. Children of parents with panic disorders have a higher incidence of behavioral disorders very early in life, before you would think major environmental impacts would occur.

A growing body of evidence shows that infants who tend to be shy, timid, and constrained in social situations — even in the first few weeks of life — have higher rates of anxiety disorders when they get older.

Symptoms

Symptoms of anxiety can differ based on the specific anxiety disorder a person has. However, all anxiety disorders are linked together by common symptoms that include excessive, irrational fear and dread. Because these are also possible symptoms of other conditions, people who believe they have anxiety symptoms are encouraged to see a doctor for proper diagnosis.

Adolescents and Anxiety

Scientists have found that adolescence is an important period for the diagnosis and treatment of an anxiety disorder. Of adolescents who have any one of the mood or anxiety disorders, 42 percent still have an anxiety or depressive disorder in adulthood. In contrast, only 5 percent of adolescents who were healthy go on to develop one of the disorders. It is likely that if we aggressively treat adolescents who suffer from mood and anxiety disorders, we can prevent many of these disorders from becoming chronic.

Treatment Options

Anxiety treatment can be effective at any age. If you think you may have an anxiety disorder, don’t hesitate to discuss it with your healthcare provider. There are many different types of treatments available, and these can be tailored to specific problems. In some cases, psychotherapy, or counseling, is sufficient. In other cases, medication alone can be effective. Some people may need both.

A number of medications that were originally approved for treating depression have been found to be effective for anxiety disorders as well. Some of the newest of these antidepressants are called selective serotonin reuptake inhibitors (SSRIs). Other antianxiety medications include groups of drugs called benzodiazepines and beta-blockers. If one medication is not effective, others can be tried. New medications are currently under development to treat anxiety symptoms.

Two clinically proven effective forms of psychotherapy used to treat anxiety disorders are behavioral therapy and cognitive-behavioral therapy. Behavioral therapy focuses on changing specific actions, and uses several techniques to stop unwanted behaviors. In addition to the behavioral therapy techniques, cognitive-behavioral therapy teaches patients to understand and change their thinking patterns so that they can react differently to the situations that cause them anxiety.

(Click Anxiety Treatment for a closer look at the treatment options for this condition.)

Anxiety and Other Conditions

It is common for an anxiety disorder to accompany depression, eating disorders, substance abuse, or another anxiety disorder. Anxiety disorders can also co-exist with illnesses such as cancer or heart disease. In such instances, the accompanying disorders will also need to be treated. Before beginning any treatment, however, it is important to have a thorough medical examination to rule out other possible causes of symptoms.

(Click Anxiety and Cancer for more information.)

Statistics on Anxiety

Each year, approximately 19.1 million American adults ages 18 to 54 (about 13.3 percent of people in this age group) have an anxiety disorder.

Anxiety disorders frequently co-occur with depressive disorders, eating disorders, or substance abuse. Many people have more than one anxiety disorder.

Women are more likely than men to have an anxiety disorder. Approximately twice as many women as men suffer from panic disorder, post-traumatic stress disorder, generalized anxiety disorder, agoraphobia, and specific phobia, though about equal numbers of women and men have obsessive-compulsive disorder and social phobia.