Lifestyle risk factors for osteoporosis

MedSurg Nursing, Oct, 1997 by Terry N. Thomas

Ninety-nine percent of the body's calcium is used by the body to strengthen bone and teeth. Calcium is important to bone health throughout the lifespan. Peak bone mass usually occurs by age 17, but some further bone mass growth continues into the 30s. Low calcium intake may be directly related to failure to achieve peak bone mass in adolescence. Adequate calcium intake should occur throughout the lifespan as it is an important adjunct to bone strength (Wardlaw & Weese, 1995). Calcium is best absorbed through the upper gastrointestinal tract and is better absorbed in younger women (Wardlaw & Weese, 1995). This increased absorption in younger women may be due to higher estrogen levels. Estrogen increases synthesis of calcitriol, the vitamin D hormone which plays a large role in calcium absorption in the upper small intestine. Therefore older women who have inadequate intake of calcium, have a decreased ability to absorb calcium, are postmenopausal, and drink alcohol excessively are at high risk for developing osteoporosis.

Combined with all of the above is the fact that high alcohol consumption can lead to balance difficulties which place a woman at risk for falls. If a woman with poor bone health falls, she is more likely to break a bone than a woman with good bone health. A fracture can lead to other complications, such as pain and further immobility, which together increase the risk for osteoporosis.

Caffeine Intake

Caffeine intake puts women at risk for osteoporosis for a different reason than the physiology mentioned earlier. Caffeine causes increased calcium excretion in the urine. This increased excretion of calcium in the urine could lead to bone maintenance problems, especially if calcium intake is low. Since there tends to be high consumption of caffeine-containing beverages (coffee, cola) in adult women, women of all ages should be informed that high caffeine intake coupled with inadequate calcium intake could lead to decreased bone density (Wardlaw, 1993; Wardlaw & Weese, 1995).

Calcium Intake

Low calcium intake is a major cause of decreased bone density which may lead to osteoporosis (Wardlaw, 1993). Young girls at the start of menses and throughout their teens and 20s should ingest adequate calcium (Cerrato, 1992; Miller, 1995). Calcium intake should continue throughout adulthood. For ages 25 to 49 and ages 50 to 64 for women on hormone replacement therapy, 1,000 mg per day is recommended. For ages 50 to 64 in women not on hormone replacement therapy, and women over 65, 1,500 mg of calcium is recommended (Whipple, 1995). According to Wardlaw and Weese (1995), most people obtain 50% of their calcium from dairy products. White bread, rolls, crackers, and other foods made with milk account for another 20%. Calcium-enriched foods are also available in grocery stores for those who do not ingest enough calcium from dairy products. Calcium supplements may also be used. Calcium citrate is best utilized by the body (Dawson-Hughes et al., 1990) but is expensive. A calcium supplement should be chewable and taken between meals for greater absorption in women under 60 (Miller, 1995). For women over 60, calcium supplements are better absorbed when taken with meals (Sardana, 1992).