Osteoporosis and calcium
Calcium is the most abundant mineral found in the body and most of it is found in our bones. It is one of the most important minerals involved in the treatment and prevention of osteoporosis. Calcium alters the bone-related hormones and possibly the local hormones induced by mechanical stress. Calcium could alter the physical-chemical properties of the bone
mineral. The major mechanism whereby calcium effects bone is probably through inhibition of PTH secretion. Direct effects of calcium on the calcium receptor could also play a role.
The bones of the human skeleton contain 99.5% of the total calcium in the body. The calcium within bones is available to the body should the body need it for other purposes (see the chapter on the symptoms of hyperparathyroidism for more on this topic). It is the activity of bone osteoclasts which absorb the calcium in the bone and release it into the blood stream (more about this on our parathyroid and osteoporosis page). Unlike most of the people think, there is an intense biological activity inside our bones. They are being renewed constantly by new tissue replacing the old one. During childhood and adolescence, there’s more production of new tissue than destruction of the old one, but at some point, somewhere around the 30 or 35 years of age, the process is inverted and we start to loose more tissue than what we can replace. In women the process is accelerated after the menopause (he period marked by the natural and permanent cessation of menstruation, occurring usually between the ages of 45 and 55); this is because their bodies stop producing the hormone known as estrogen, one of which functions is to preserve the osseous mass.
Not only is calcium vitally important in preventing osteoporosis, the correct form of calcium is just as important. The daily recommended dietary calcium intake varies by age, sex, and menopausal status. In young people, calcium intake should be 800 mg per day for children ages three to eight and 1,300 mg per day for children and adolescents ages nine to 17. The standard recommended dose for people over 50 is about 1,200 mg per day, but may be higher or lower depending on risk factors. Even doses of 1,000 mg may help preserve bone in many postmenopausal women without osteoporosis, including during winter months (when bone loss is greatest). In women who have already experienced osteoporosis-related fractures, however, 1,000 mg daily may not add any protective benefits without bone-building medication.
Dietary protein and caffeine can increase urine loss of calcium, but they do not affect the absorption from the intestines. These effects can be measured and are statistically significant, but becomes clinically significant only at large intakes. In fact, a latte will result in positive calcium balance! Calcium absorption is inhibited to a modest degree by fiber in the diet. Although the calcium content in spinach is high, almost none gets absorbed. Vitamin D must be adequate for optimal absorption of calcium. The vitamin D has a very long half-life and does not need to be taken at the same time as the calcium.
Calcium may cause constipation, nausea, or vomiting. Individuals who have had kidney stones should have the calcium level in their urine checked to see if the increased calcium ingestion will contribute to kidney stones. Vitamin D doses recommended by your doctor should not be exceeded. Taking high-dose vitamin D for a long time can lead to toxicity and cause symptoms such as weakness, headache, drowsiness, muscle pain, bone pain, and elevated liver enzyme levels.
Calcium supplements exist in different compounds, such as calcium carbonate (Caltrate, Os-Cal, Tums), calcium citrate (Citracal), calcium gluconate, and calcium lactate. The best source of calcium in the diet is from milk fortified with vitamin D. Four glasses of milk provide about 1,200 mg of calcium. Skim milk and non-fat dairy products are the best choices and provide the same calcium as dairy products with fat. Adolescents should drink about three 8-ounce glasses of low-fat milk daily. (Teenage girls who fear that milk is fattening can take comfort in a study reporting that girls who consumed lots of dairy products were no more likely to become overweight than their milk-shunning peers.) In fact drinking carbonated beverages, particularly cola, increases the risk for bone fractures. Other calcium-rich foods include shrimp, canned salmon or sardines, black strap molasses, calcium-fortified tofu, and almonds. A number of commercial foods, including orange juice and some cereals, are now calcium fortified. Dark green vegetables (broccoli, kale, turnip greens) are rich in calcium but little of it is absorbed (kale is best).
More information on osteoporosis
What is osteoporosis? - Osteoporosis is a thinning and weakening of the bones, usually associated with the aging process. Osteoporosis is a disease, often with no detectable symptoms.
Building and maintaining skeletal health - Factors involved in building and maintaining skeletal health are adequate nutrition and body weight, exposure to sex hormones at puberty, and physical activity.
What types of osteoporosis are there? - Osteoporosis can be classified in various ways based on diagnostic categories, etiology. Osteoporosis can be classified as either primary osteoporosis or secondary osteoporosis.
What causes osteoporosis? - Osteoporosis is related to the loss of bone mass that occurs as part of the natural process of aging. Osteoporosis results when there is excess bone loss without adequate replacement.
What are the risk factors for osteoporosis? - Many disorders are associated with increased risk of osteoporosis. Osteoporosis is far more prevalent in women after menopause due to the loss of the hormone estrogen.
What're the risk factors for primary osteoporosis? - Risk factors for primary osteoporosis include age, gender, race, figure type, lifestyle, diet, and lack of sunlight.
What're the risk factors for secondary osteoporosis? - Risk factors for secondary osteoporosis include genetic disorders, hypogonadal states, endocrine disorders,hematologic disorders, nutritional deficiencies, drugs.
What are the consequences of osteoporosis? - Consequences due to osteoporosis are increased risk of fracture with minor trauma, frequency of traumatic events from lifting and bending impact.
What are the symptoms of osteoporosis? - Patients with uncomplicated osteoporosis may be asymptomatic or may have pain in the bones or muscles, particularly of the back. Osteoporosis becomes apparent in dramatic fashion.
How is osteoporosis diagnosed? - The diagnosis of osteoporosis is usually made by your doctor using a combination of a complete medical history and physical examination.
What're the treatments for osteoporosis? - Treatment for osteoporosis includes eating a diet rich in calcium and vitamin D, getting regular exercise, and taking medication to reduce bone loss and increase bone thickness.
What osteoporosis medications (drugs) are available? - Medications (drugs) to cure osteoporosis include bisphosphanates (Fosamax), calcitonin (Miacalcin), raloxifene, estrogen, and selective estrogen receptor modulators (SERMs).
How to treat osteoporosis in men? - Alendronate and teriparatide have been approved to treat osteoporosis in men. Calcitonin may work in men, treatment with testosterone appears to increase bone density.
How to treat osteoporosis in women? - The non-hormonal bisphosphonate drugs, alendronate and risedronate prevent and treat postmenopausal osteoporosis. Raloxifene is approved for preventing and treating osteoporosis.
What lifestyle changes can help osteoporosis? - Alcohol consumption should also be kept within safe limits. Supplements of calcium plus vitamin D may help maintain bone density. Limiting sodium and avoiding junk food.
What osteoporosis exercises are suggested? - Exercise is very important for slowing the progression of osteoporosis. Taking regular exercise is the single most important action improve the strength of their bones.
What osteoporosis diet is suggested? - A good calcium intake is essential throughout life for healthy bones. Vitamin D helps the absorption of calcium from the intestines. Reducing salt may be useful for osteoporosis patients.
What can be done to prevent osteoporosis? - For prevention and treatment of osteoporosis, patients should be encouraged to stop smoking, limit alcohol consumption and perform weight-bearing exercise.
Osteoporosis and calcium - Calcium could alter the physical-chemical properties of the bone mineral. The daily recommended dietary calcium intake varies by age, sex, and menopausal status.
Osteoporosis and magnesium - Magnesium supplementation is as important as calcium supplementation in the treatment and prevention of osteoporosis.
Osteoporosis and vitamin D - Vitamin D is necessary for the absorption of calcium in the stomach and gastrointestinal tract and is the essential companion to calcium in maintaining strong bones to prevent osteoporosis.