Osteoporosis

Osteoporosis, or "porous bones," is the weakening of bones caused by an imbalance between bone building and bone destruction. People typically lose bone as they age, even if they consume the recommended intake of calcium necessary to maintain optimal bone health. Osteoporosis can result in severe limitation of the body's ability to move and perform everyday tasks, and puts those affected by it (especially the elderly) at risk for fractures (especially hip fractures) and bone degeneration. An estimated 10 million Americans - 8 million women and 2 million men - have osteoporosis. Another 34 million have low bone mass, placing them at increased risk for osteoporosis.(1)

Achieving adequate calcium intake and maximizing bone stores during the time when bone is rapidly deposited (up to age 30) provides an good foundation for the future. But it will not prevent bone loss later in life. The loss of bone with aging is due to several reasons, including genetic factors, physical inactivity, and lower levels of circulating hormones (estrogen in women and testosterone in men).

Postmenopausal women account for 80 percent of all cases of osteoporosis because estrogen production declines rapidly at menopause. Not surprisingly, men are also at risk of developing osteoporosis, but they tend to do so 5-10 years later than women, since testosterone levels do not fall abruptly the way estrogen does in women. It is estimated that osteoporosis will cause half of all women over age 50 to suffer a fracture of the hip, wrist, or vertebra.

Without dairy products in the diet, it is very difficult to get enough calcium. Calcium supplements are useful if you do not consume enough dairy in your diet.

About half of all U.S. children less than 5 years of age don't get enough calcium in their diet. And once children reach their teen years, more than 85% of girls and 60% of boys fail to take in the recommended daily allowance (RDA) of calcium. According to z report made by the National Institutes of Health (NIH) in January, 2002, American children and teens are in the midst of a "calcium crisis" because nearly 90 percent of adult bone mass is established by the end of the teen years.

Recommended daily allowance for Calcium

The body gets the calcium it needs in two ways. One is by eating foods that contain calcium.

The other way the body gets calcium is by pulling it from bones. This happens when blood levels of calcium drop too low, usually when it's been a while since having eaten a meal containing calcium. Ideally, the calcium that is "borrowed" from the bones will be replaced at a later point. But, this doesn't always happen. Most important, this payback can't be accomplished simply by eating more calcium.

Bone is living tissue that is always in flux. Throughout the lifespan, bones are constantly being broken down and built up in a process known as remodeling.

In healthy individuals who get enough calcium and physical activity, bone production exceeds bone destruction up to about age 30. After that, destruction typically exceeds production.

Good sources of Calcium include:

A good food source of calcium contains a substantial amount of calcium in relation to its calorie content and contributes at least 10 percent of the U.S. Recommended Dietary Allowance (U.S. RDA) for calcium in a selected serving size. The U.S. RDA for calcium is 1,000 milligrams per day. The 1989 RDA has been set at 1,200 milligrams per day for women and men 19 to 24 years of age and 800 milligrams for women and men 25 to 50 years of age.

Milk, sardines, calcium fortified orange juice, yogurt, cheddar cheese, American cheese, canned salmon.

A glass of low fat milk, a low fat yogurt and 2oz of lower fat cheese provides the average person with the Calcium they need.

Calcium absorption is dependent upon:

the calcium needs of the body,
the foods eaten, and
the amount of calcium in the foods eaten.
Vitamin D, whether from diet or exposure to the ultraviolet light of the sun, increases calcium absorption.

Calcium absorption tends to decrease with increased age for both men and women.

Calcium from most plant sources is simply too poorly available to account for a high percent of the RDA. (If you are a vegetarian you may wish to read about calcium bioavailability at
http://www.nutritionnewsfocus.com/archive/a1/CalcBioAvl.html.)