Vitamin D is needed for the absorption of calcium in the intestines. To maintain healthy and strong bones, you need calcium. Calcium is absorbed mainly from food sources that are high in calcium such as sardines, oatmeal, milk, yogurt and soybeans. Vitamin D is made in the skin under direct sunlight. Adequate vitamin D intake from foods such as fish, eggs and cod liver oil helps prevent osteoporosis.
How the Body Regulates Calcium
Calcium is regulated by the thyroid and parathyroid glands; they produce calcitonin and thyroid hormone, respectively. The parathyroid gland produces parathyroid hormone when calcium is low; the parathyroid hormone causes the break down of bone, which releases calcium into the blood. Excess parathyroid hormone worsens an already weak bone. Elevated calcium in blood is reduced by calcitonin, which is produced by the thyroid gland.
Risk Factors
The risk for osteoporosis increases with advanced age; females are also at risk. In women, estrogen becomes deficient in menopause, leading to a rapid loss in bone strength; in males, a drop in the male sex hormone, testosterone, has less effect on bone.
Alcoholism and smoking in excess are toxic to bone-forming cells. Other risk factors include vitamin D deficiency and malnutrition. Lack of physical activity can also cause a major loss in bone strength.
Major Complications
Bone fractures in osteoporosis occur without significant stress on bone. Fractures can occur anywhere in the body. Fractures of bones in the back affect posture and reduce mobility. Fracture of a long bone, such as the one in the thigh, will require surgery. Osteoporosis increases the seriousness of injuries associated with falls in elderly people.
Preventative Measures
Lifestyle changes can dramatically reduce risk for osteoporosis. Quitting smoking and drinking are big steps in preventing osteoporosis; excessive smoking and alcoholism are damaging to cells that form bone. Bone weakens with age but regular exercise, such as walking and jogging, slows down the loss in bone strength. Exercise should take place for at least 30 minutes a day at least four days per week.
Treatment and Supplementation
Bisphosphonates such as sodium alendronate, risedronate or ibandronate are drugs of choice; they are very effective in reducing the risk of fracture in osteoporosis. Bisphosphonates are prescribed by a physician.
Estrogen prevents bone density loss in women. Post-menopausal women are unable to make estrogen, putting them at risk for osteoporosis. A 2006 article in BMJ only recommends the replacement of estrogen for younger post-menopausal women.
Vitamin D and calcium should not be used alone as treatment, since studies have not consistently demonstrated their effectiveness in preventing osteoporotic fractures. The supplementation of vitamin D should be at doses of 400 to 600 international units, or IUs, per day. Vitamin D should be given with calcium at doses of 500 to 1,200 mg per day.
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